Refactor html templates

This commit entirely refactors the use of html templates. Instead of
inheriting from a shared template, we insert the results into a base
template.

internal/dis/component/auth/auth.go

@@ -5,7 +5,7 @@ import (
 	"net/http"
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/sql"
 	"github.com/FAU-CDI/wisski-distillery/pkg/lazy"
 	"github.com/gorilla/sessions"
@@ -17,7 +17,7 @@ type Auth struct {
 	Dependencies struct {
 		SQL             *sql.SQL
 		UserDeleteHooks []component.UserDeleteHook
-		Templating      *templates.Templating
+		Templating      *templating.Templating
 	}
 
 	store lazy.Lazy[sessions.Store]

internal/dis/component/auth/login.html

@@ -1,5 +1,4 @@
-{{ template "_form.html" . }}
+{{ template "form.html" . }}
-{{ define "form/title" }}Login Required{{ end }}
 {{ define "form/button" }}Login{{ end }}
 {{ define "form/inside" }}
 <div class="pure-form-group">

internal/dis/component/auth/panel/panel.go

@@ -9,7 +9,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/auth/next"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/auth/policy"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/instances"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/ssh2/sshkeys"
 	"github.com/FAU-CDI/wisski-distillery/internal/models"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
@@ -20,7 +20,7 @@ type UserPanel struct {
 	component.Base
 	Dependencies struct {
 		Auth       *auth.Auth
-		Templating *templates.Templating
+		Templating *templating.Templating
 		Policy     *policy.Policy
 		Instances  *instances.Instances
 		Next       *next.Next
@@ -106,30 +106,25 @@ func (panel *UserPanel) HandleRoute(ctx context.Context, route string) (http.Han
 }
 
 type userFormContext struct {
-	templates.BaseContext
+	templating.RuntimeFlags
 	httpx.FormContext
 
 	User *models.User
 }
 
-func (panel *UserPanel) UserFormContext2(tpl *templates.Template[userFormContext], last component.MenuItem, gaps ...templates.BaseContextGaps) func(ctx httpx.FormContext, r *http.Request) any {
+func (panel *UserPanel) UserFormContext(tpl *templating.Template[userFormContext], last component.MenuItem, funcs ...templating.FlagFunc) func(ctx httpx.FormContext, r *http.Request) any {
-	var g templates.BaseContextGaps
+	funcs = append(funcs, func(flags templating.Flags, r *http.Request) templating.Flags {
-	if len(gaps) > 1 {
+		flags.Crumbs = append(flags.Crumbs, component.MenuItem{})
-		panic("UserFormContext2: gaps must be of length 0 or 1")
+		copy(flags.Crumbs[1:], flags.Crumbs)
-	}
+		flags.Crumbs[0] = component.MenuItem{Title: "User", Path: "/user/"}
-	if len(gaps) == 1 {
+		return flags
-		g = gaps[0]
+	})
-	}
-	g.Crumbs = []component.MenuItem{
-		{Title: "User", Path: "/user/"},
-		last,
-	}
 
-	return templates.MappedHandler(tpl, func(ctx httpx.FormContext, r *http.Request) (userFormContext, templates.BaseContextGaps) {
+	return func(ctx httpx.FormContext, r *http.Request) any {
 		uctx := userFormContext{FormContext: ctx}
 		if user, err := panel.Dependencies.Auth.UserOf(r); err == nil {
 			uctx.User = &user.User
 		}
-		return uctx, g
+		return tpl.Context(r, uctx, funcs...)
-	})
+	}
 }

internal/dis/component/auth/panel/password.go

@@ -9,14 +9,19 @@ import (
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	templating "github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx/field"
 )
 
 //go:embed "templates/password.html"
 var passwordHTML []byte
-var passwordTemplate = templating.Parse[userFormContext]("password.html", passwordHTML, assets.AssetsUser)
+var passwordTemplate = templating.Parse[userFormContext](
+	"password.html", passwordHTML, httpx.FormTemplate,
+
+	templating.Title("Change Password"),
+	templating.Assets(assets.AssetsUser),
+)
 
 var (
 	errPasswordsNotIdentical = errors.New("passwords are not identical")
@@ -40,7 +45,7 @@ func (panel *UserPanel) routePassword(ctx context.Context) http.Handler {
 		FieldTemplate: field.PureCSSFieldTemplate,
 
 		RenderTemplate:        tpl.Template(),
-		RenderTemplateContext: panel.UserFormContext2(tpl, component.MenuItem{Title: "Change Password", Path: "/user/password/"}),
+		RenderTemplateContext: panel.UserFormContext(tpl, component.MenuItem{Title: "Change Password", Path: "/user/password/"}),
 
 		Validate: func(r *http.Request, values map[string]string) (struct{}, error) {
 			old, passcode, new, new2 := values["old"], values["otp"], values["new"], values["new2"]

internal/dis/component/auth/panel/ssh.go

@@ -8,7 +8,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/auth"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/internal/models"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx/field"
@@ -22,10 +22,15 @@ import (
 
 //go:embed "templates/ssh.html"
 var sshHTML []byte
-var sshTemplate = templates.Parse[SSHTemplateContext]("ssh.html", sshHTML, assets.AssetsUser)
+var sshTemplate = templating.Parse[SSHTemplateContext](
+	"ssh.html", sshHTML, nil,
+
+	templating.Title("SSH Keys"),
+	templating.Assets(assets.AssetsUser),
+)
 
 type SSHTemplateContext struct {
-	templates.BaseContext
+	templating.RuntimeFlags
 
 	Keys []models.Keys
 
@@ -37,15 +42,16 @@ type SSHTemplateContext struct {
 }
 
 func (panel *UserPanel) sshRoute(ctx context.Context) http.Handler {
-	tpl := sshTemplate.Prepare(panel.Dependencies.Templating, templates.BaseContextGaps{
+	tpl := sshTemplate.Prepare(
-		Crumbs: []component.MenuItem{
+		panel.Dependencies.Templating,
-			{Title: "User", Path: "/user/"},
+		templating.Crumbs(
-			{Title: "SSH Keys", Path: "/user/ssh/"},
+			component.MenuItem{Title: "User", Path: "/user/"},
-		},
+			component.MenuItem{Title: "SSH Keys", Path: "/user/ssh/"},
-		Actions: []component.MenuItem{
+		),
-			{Title: "Add New Key", Path: "/user/ssh/add/"},
+		templating.Actions(
-		},
+			component.MenuItem{Title: "Add New Key", Path: "/user/ssh/add/"},
-	})
+		),
+	)
 
 	return tpl.HTMLHandler(func(r *http.Request) (sc SSHTemplateContext, err error) {
 		user, err := panel.Dependencies.Auth.UserOf(r)
@@ -114,7 +120,11 @@ func (panel *UserPanel) sshDeleteRoute(ctx context.Context) http.Handler {
 
 //go:embed "templates/ssh_add.html"
 var sshAddHTML []byte
-var sshAddTemplate = templates.ParseForm("ssh_add.html", sshAddHTML, assets.AssetsUser)
+var sshAddTemplate = templating.ParseForm(
+	"ssh_add.html", sshAddHTML, httpx.FormTemplate,
+	templating.Title("Add SSH Key"),
+	templating.Assets(assets.AssetsUser),
+)
 
 type addKeyResult struct {
 	User    *auth.AuthUser
@@ -123,13 +133,14 @@ type addKeyResult struct {
 }
 
 func (panel *UserPanel) sshAddRoute(ctx context.Context) http.Handler {
-	tpl := sshAddTemplate.Prepare(panel.Dependencies.Templating, templates.BaseContextGaps{
+	tpl := sshAddTemplate.Prepare(
-		Crumbs: []component.MenuItem{
+		panel.Dependencies.Templating,
-			{Title: "User", Path: "/user/"},
+		templating.Crumbs(
-			{Title: "SSH Keys", Path: "/user/ssh/"},
+			component.MenuItem{Title: "User", Path: "/user/"},
-			{Title: "Add New Key", Path: "/user/ssh/add/"},
+			component.MenuItem{Title: "SSH Keys", Path: "/user/ssh/"},
-		},
+			component.MenuItem{Title: "Add New Key", Path: "/user/ssh/add/"},
-	})
+		),
+	)
 
 	return &httpx.Form[addKeyResult]{
 		Fields: []field.Field{
@@ -139,7 +150,7 @@ func (panel *UserPanel) sshAddRoute(ctx context.Context) http.Handler {
 		FieldTemplate: field.PureCSSFieldTemplate,
 
 		RenderTemplate:        tpl.Template(),
-		RenderTemplateContext: templates.FormTemplateContext(tpl),
+		RenderTemplateContext: templating.FormTemplateContext(tpl),
 
 		Validate: func(r *http.Request, values map[string]string) (ak addKeyResult, err error) {
 			ak.User, err = panel.Dependencies.Auth.UserOf(r)

internal/dis/component/auth/panel/templates/password.html

@@ -1,3 +1,2 @@
-{{ template "_form.html" . }}
+{{ template "form.html" . }}
-{{ define "form/title" }}Change Password{{ end }}
 {{ define "form/button" }}Update{{ end }}

internal/dis/component/auth/panel/templates/ssh.html

@@ -1,8 +1,3 @@
-{{ template "_base.html" . }}
-{{ define "title" }}SSH Keys{{ end }}
-
-{{ define "content" }}
-
 <div class="pure-u-1">
     <p>
         This page allows you to add, view and remove ssh keys to and from your distillery account.
@@ -101,4 +96,3 @@ Host {{ .Domain }}.proxy
     </code>
 </div>
 </div>
-{{ end }}

internal/dis/component/auth/panel/templates/ssh_add.html

@@ -1,7 +1,4 @@
-{{ template "_form.html" . }}
-{{ define "form/title" }}Add SSH Key{{ end }}
 {{ define "form/button" }}Add{{ end }}
-
 {{ define "form/inside" }}
 <div>
    <p>

internal/dis/component/auth/panel/templates/totp_disable.html

@@ -1,5 +1,5 @@
-{{ template "_form.html" . }}
+{{ template "form.html" . }}
-{{ define "form/title" }}Disable TOTP{{ end }}
+
 {{ define "form/button" }}Disable{{ end }}
 
 {{ define "form/inside" }}

internal/dis/component/auth/panel/templates/totp_enable.html

@@ -1,5 +1,4 @@
-{{ template "_form.html" . }}
+{{ template "form.html" . }}
-{{ define "form/title" }}Enable TOTP{{ end }}
 {{ define "form/button" }}Enable{{ end }}
 {{ define "form/inside" }}
 <div>

internal/dis/component/auth/panel/templates/totp_enroll.html

@@ -1,5 +1,3 @@
-{{ template "_form.html" . }}
-{{ define "form/title" }}Enable TOTP{{ end }}
 {{ define "form/button" }}Enable{{ end }}
 {{ define "form/inside" }}
 <div>

internal/dis/component/auth/panel/templates/user.html

@@ -1,7 +1,3 @@
-{{ template "_base.html" . }}
-{{ define "title" }}{{ .User.User }}{{ end }}
-
-{{ define "content" }}
 <div class="pure-u-1">
     <p>
         <ul>
@@ -80,5 +76,3 @@
         </div>
     </div>
 </div>
-
-{{ end }}

internal/dis/component/auth/panel/totp.go

@@ -8,7 +8,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/auth"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx/field"
 
@@ -17,7 +17,12 @@ import (
 
 //go:embed "templates/totp_enable.html"
 var totpEnableHTML []byte
-var totpEnable = templates.Parse[userFormContext]("totp_enable.html", totpEnableHTML, assets.AssetsUser)
+var totpEnable = templating.Parse[userFormContext](
+	"totp_enable.html", totpEnableHTML, httpx.FormTemplate,
+
+	templating.Title("Enable TOTP"),
+	templating.Assets(assets.AssetsUser),
+)
 
 func (panel *UserPanel) routeTOTPEnable(ctx context.Context) http.Handler {
 	tpl := totpEnable.Prepare(panel.Dependencies.Templating)
@@ -34,7 +39,7 @@ func (panel *UserPanel) routeTOTPEnable(ctx context.Context) http.Handler {
 		},
 
 		RenderTemplate:        tpl.Template(),
-		RenderTemplateContext: panel.UserFormContext2(tpl, component.MenuItem{Title: "Enable TOTP", Path: "/user/totp/enable/"}),
+		RenderTemplateContext: panel.UserFormContext(tpl, component.MenuItem{Title: "Enable TOTP", Path: "/user/totp/enable/"}),
 
 		Validate: func(r *http.Request, values map[string]string) (struct{}, error) {
 			password := values["password"]
@@ -69,7 +74,12 @@ func (panel *UserPanel) routeTOTPEnable(ctx context.Context) http.Handler {
 
 //go:embed "templates/totp_enroll.html"
 var totpEnrollHTML []byte
-var totpEnrollTemplate = templates.Parse[totpEnrollContext]("totp_enroll.html", totpEnrollHTML, assets.AssetsUser)
+var totpEnrollTemplate = templating.Parse[totpEnrollContext](
+	"totp_enroll.html", totpEnrollHTML, httpx.FormTemplate,
+
+	templating.Title("Enable TOTP"),
+	templating.Assets(assets.AssetsUser),
+)
 
 type totpEnrollContext struct {
 	userFormContext
@@ -80,12 +90,13 @@ type totpEnrollContext struct {
 }
 
 func (panel *UserPanel) routeTOTPEnroll(ctx context.Context) http.Handler {
-	tpl := totpEnrollTemplate.Prepare(panel.Dependencies.Templating, templates.BaseContextGaps{
+	tpl := totpEnrollTemplate.Prepare(
-		Crumbs: []component.MenuItem{
+		panel.Dependencies.Templating,
-			{Title: "User", Path: "/user/"},
+		templating.Crumbs(
-			{Title: "Enable TOTP", Path: "/user/totp/enable/"},
+			component.MenuItem{Title: "User", Path: "/user/"},
-		},
+			component.MenuItem{Title: "Enable TOTP", Path: "/user/totp/enable/"},
-	})
+		),
+	)
 
 	return &httpx.Form[struct{}]{
 		Fields: []field.Field{
@@ -98,9 +109,7 @@ func (panel *UserPanel) routeTOTPEnroll(ctx context.Context) http.Handler {
 			user, err := panel.Dependencies.Auth.UserOf(r)
 			return struct{}{}, err == nil && user != nil && user.IsTOTPEnabled()
 		},
-		RenderForm: func(context httpx.FormContext, w http.ResponseWriter, r *http.Request) {
+		RenderTemplateContext: func(context httpx.FormContext, r *http.Request) any {
-			// TODO: Do we want to reuse the same function here?
-
 			user, err := panel.Dependencies.Auth.UserOf(r)
 
 			ctx := totpEnrollContext{
@@ -120,8 +129,10 @@ func (panel *UserPanel) routeTOTPEnroll(ctx context.Context) http.Handler {
 					ctx.TOTPURL = template.URL(secret.URL())
 				}
 			}
-			tpl.Execute(w, r, ctx)
+
+			return tpl.Context(r, ctx)
 		},
+		RenderTemplate: tpl.Template(),
 
 		Validate: func(r *http.Request, values map[string]string) (struct{}, error) {
 			password, otp := values["password"], values["otp"]
@@ -156,7 +167,12 @@ func (panel *UserPanel) routeTOTPEnroll(ctx context.Context) http.Handler {
 
 //go:embed "templates/totp_disable.html"
 var totpDisableHTML []byte
-var totpDisableTemplate = templates.Parse[userFormContext]("totp_disable.html", totpDisableHTML, assets.AssetsUser)
+var totpDisableTemplate = templating.Parse[userFormContext](
+	"totp_disable.html", totpDisableHTML, httpx.FormTemplate,
+
+	templating.Title("Disable TOTP"),
+	templating.Assets(assets.AssetsUser),
+)
 
 func (panel *UserPanel) routeTOTPDisable(ctx context.Context) http.Handler {
 	tpl := totpDisableTemplate.Prepare(panel.Dependencies.Templating)
@@ -173,7 +189,7 @@ func (panel *UserPanel) routeTOTPDisable(ctx context.Context) http.Handler {
 			return struct{}{}, err == nil && user != nil && !user.IsTOTPEnabled()
 		},
 		RenderTemplate:        tpl.Template(),
-		RenderTemplateContext: panel.UserFormContext2(tpl, component.MenuItem{Title: "Disable TOTP", Path: "/user/totp/disable/"}),
+		RenderTemplateContext: panel.UserFormContext(tpl, component.MenuItem{Title: "Disable TOTP", Path: "/user/totp/disable/"}),
 
 		Validate: func(r *http.Request, values map[string]string) (struct{}, error) {
 			password, otp := values["password"], values["otp"]

internal/dis/component/auth/panel/user.go

@@ -10,16 +10,20 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/auth"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/internal/models"
 )
 
 //go:embed "templates/user.html"
 var userHTML []byte
-var userTemplate = templates.Parse[userContext]("user.html", userHTML, assets.AssetsUser)
+var userTemplate = templating.Parse[userContext](
+	"user.html", userHTML, nil,
+
+	templating.Assets(assets.AssetsUser),
+)
 
 type userContext struct {
-	templates.BaseContext
+	templating.RuntimeFlags
 	*auth.AuthUser
 
 	Grants []GrantWithURL
@@ -31,41 +35,47 @@ type GrantWithURL struct {
 }
 
 func (panel *UserPanel) routeUser(ctx context.Context) http.Handler {
-	tpl := userTemplate.Prepare(panel.Dependencies.Templating, templates.BaseContextGaps{
+	tpl := userTemplate.Prepare(
-		Crumbs: []component.MenuItem{
+		panel.Dependencies.Templating,
-			{Title: "User", Path: "/user/"},
+		templating.Crumbs(
-		},
+			component.MenuItem{Title: "User", Path: "/user/"},
-		Actions: []component.MenuItem{
+		),
-			{Title: "Change Password", Path: "/user/password/"},
+		templating.Actions(
-			{Title: "*to be replaced*", Path: ""},
+			component.MenuItem{Title: "Change Password", Path: "/user/password/"},
-			{Title: "SSH Keys", Path: "/user/ssh/"},
+			component.DummyMenuItem,
-		},
+			component.MenuItem{Title: "SSH Keys", Path: "/user/ssh/"},
-	})
+		),
+	)
 
-	return tpl.HTMLHandlerWithGaps(func(r *http.Request, gaps *templates.BaseContextGaps) (uc userContext, err error) {
+	return tpl.HTMLHandlerWithFlags(func(r *http.Request) (uc userContext, funcs []templating.FlagFunc, err error) {
 		// find the user
 		uc.AuthUser, err = panel.Dependencies.Auth.UserOf(r)
 		if err != nil || uc.AuthUser == nil {
-			return uc, err
+			return uc, nil, err
 		}
 
-		// build the gaps
+		// replace the totp action in the menu
+		var totpAction component.MenuItem
 		if uc.AuthUser.IsTOTPEnabled() {
-			gaps.Actions[1] = component.MenuItem{
+			totpAction = component.MenuItem{
 				Title: "Disable Passcode (TOTP)",
 				Path:  "/user/totp/disable/",
 			}
 		} else {
-			gaps.Actions[1] = component.MenuItem{
+			totpAction = component.MenuItem{
 				Title: "Enable Passcode (TOTP)",
 				Path:  "/user/totp/enable/",
 			}
 		}
+		funcs = []templating.FlagFunc{
+			templating.ReplaceAction(1, totpAction),
+			templating.Title(uc.AuthUser.User.User),
+		}
 
 		// find the grants
 		grants, err := panel.Dependencies.Policy.User(r.Context(), uc.AuthUser.User.User)
 		if err != nil {
-			return uc, err
+			return uc, nil, err
 		}
 
 		uc.Grants = make([]GrantWithURL, len(grants))
@@ -74,11 +84,11 @@ func (panel *UserPanel) routeUser(ctx context.Context) http.Handler {
 
 			url, err := panel.Dependencies.Next.Next(r.Context(), grant.Slug, "/")
 			if err != nil {
-				return uc, err
+				return uc, nil, err
 			}
 			uc.Grants[i].URL = template.URL(url)
 		}
 
-		return uc, err
+		return uc, funcs, err
 	})
 }

internal/dis/component/auth/session.go

@@ -9,7 +9,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx/field"
 	"github.com/gorilla/sessions"
@@ -120,7 +120,12 @@ func (auth *Auth) Logout(w http.ResponseWriter, r *http.Request) error {
 
 //go:embed "login.html"
 var loginHTML []byte
-var loginTemplate = templates.ParseForm("login.html", loginHTML, assets.AssetsUser)
+var loginTemplate = templating.ParseForm(
+	"login.html", loginHTML, httpx.FormTemplate,
+
+	templating.Title("Login Required"),
+	templating.Assets(assets.AssetsUser),
+)
 
 var loginResponse = httpx.Response{
 	ContentType: "text/plain",
@@ -131,7 +136,15 @@ var errLoginFailed = errors.New("Login failed")
 
 // authLogin implements a view to login a user
 func (auth *Auth) authLogin(ctx context.Context) http.Handler {
-	tpl := loginTemplate.Prepare(auth.Dependencies.Templating)
+	tpl := loginTemplate.Prepare(
+		auth.Dependencies.Templating,
+		func(flags templating.Flags, r *http.Request) templating.Flags {
+			flags.Crumbs = []component.MenuItem{
+				{Title: "Login", Path: template.URL(r.URL.RequestURI())},
+			}
+			return flags
+		},
+	)
 
 	return &httpx.Form[*AuthUser]{
 		Fields: []field.Field{
@@ -141,16 +154,13 @@ func (auth *Auth) authLogin(ctx context.Context) http.Handler {
 		},
 		FieldTemplate: field.PureCSSFieldTemplate,
 
-		RenderForm: func(context httpx.FormContext, w http.ResponseWriter, r *http.Request) {
+		RenderTemplateContext: func(ctx httpx.FormContext, r *http.Request) any {
-			if context.Err != nil {
+			if ctx.Err != nil {
-				context.Err = errLoginFailed
+				ctx.Err = errLoginFailed
 			}
-			tpl.Execute(w, r, templates.BaseFormContext{FormContext: context}, templates.BaseContextGaps{
+			return tpl.Context(r, templating.NewFormContext(ctx))
-				Crumbs: []component.MenuItem{
-					{Title: "Login", Path: template.URL(r.URL.RequestURI())},
-				},
-			})
 		},
+		RenderTemplate: tpl.Template(),
 
 		Validate: func(r *http.Request, values map[string]string) (*AuthUser, error) {
 			username, password, passcode := values["username"], values["password"], values["otp"]

internal/dis/component/menu.go

@@ -19,6 +19,12 @@ type MenuItem struct {
 	Priority MenuPriority // menu priority
 }
 
+// DummyMenuItem is a dummy menu item
+// It should be replaced before being displayed to the user
+var DummyMenuItem = MenuItem{
+	Title: "* to be replaced *",
+}
+
 func MenuItemSort(a, b MenuItem) bool {
 	return a.Priority < b.Priority
 }

internal/dis/component/resolver/resolver.go

@@ -13,7 +13,8 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/auth"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/instances"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
+	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
 	"github.com/FAU-CDI/wisski-distillery/pkg/lazy"
 	"github.com/rs/zerolog"
 
@@ -24,7 +25,7 @@ type Resolver struct {
 	component.Base
 	Dependencies struct {
 		Instances  *instances.Instances
-		Templating *templates.Templating
+		Templating *templating.Templating
 		Auth       *auth.Auth
 	}
 
@@ -50,36 +51,30 @@ func (resolver *Resolver) Routes() component.Routes {
 
 //go:embed "resolver.html"
 var resolverHTML []byte
-var resolverTemplate = templates.Parse[resolverContext]("resolver.html", resolverHTML, assets.AssetsDefault)
+var resolverTemplate = templating.Parse[resolverContext](
+	"resolver.html", resolverHTML, nil,
+
+	templating.Title("Resolver"),
+	templating.Assets(assets.AssetsDefault),
+)
 
 type resolverContext struct {
-	templates.BaseContext
+	templating.RuntimeFlags
 	wdresolve.IndexContext
 }
 
 func (resolver *Resolver) HandleRoute(ctx context.Context, route string) (http.Handler, error) {
-	tpl := resolverTemplate.Prepare(resolver.Dependencies.Templating, templates.BaseContextGaps{
+	// get the resolver template
-		Crumbs: []component.MenuItem{
+	tpl := resolverTemplate.Prepare(
-			{Title: "Resolver", Path: "/wisski/get/"},
+		resolver.Dependencies.Templating,
-		},
+		templating.Crumbs(
-	})
+			component.MenuItem{Title: "Resolver", Path: "/wisski/get/"},
+		),
+	)
+	t := tpl.Template()
+
+	// extract a logger and the fallback
 	logger := zerolog.Ctx(ctx)
-
-	var p wdresolve.ResolveHandler
-	var err error
-
-	p.HandleIndex = func(context wdresolve.IndexContext, w http.ResponseWriter, r *http.Request) {
-		ctx := resolverContext{
-			IndexContext: context,
-		}
-		if !resolver.Dependencies.Auth.Has(auth.User, r) {
-			ctx.IndexContext.Prefixes = nil
-		}
-
-		tpl.Execute(w, r, ctx)
-	}
-	p.TrustXForwardedProto = true
-
 	fallback := &resolvers.Regexp{
 		Data: map[string]string{},
 	}
@@ -97,12 +92,26 @@ func (resolver *Resolver) HandleRoute(ctx context.Context, route string) (http.H
 		logger.Info().Str("name", domainName).Msg("registering legacy domain")
 	}
 
-	// resolve the prefixes
+	p := wdresolve.ResolveHandler{
-	p.Resolver = resolvers.InOrder{
+		HandleIndex: func(context wdresolve.IndexContext, w http.ResponseWriter, r *http.Request) {
+			ctx := resolverContext{
+				IndexContext: context,
+			}
+			if !resolver.Dependencies.Auth.Has(auth.User, r) {
+				ctx.IndexContext.Prefixes = nil
+			}
+			httpx.WriteHTML(tpl.Context(r, ctx), nil, t, "", w, r)
+		},
+
+		Resolver: resolvers.InOrder{
 			resolver,
 			fallback,
+		},
+
+		TrustXForwardedProto: true,
 	}
-	return p, err
+
+	return p, nil
 }
 
 func (resolver *Resolver) Target(uri string) string {

internal/dis/component/resolver/resolver.html

@@ -1,7 +1,3 @@
-{{ template "_base.html" . }}
-{{ define "title" }}Resolver{{ end }}
-
-{{ define "content" }}
 <div class="pure-u-1">
     <p>
         This page contains the global distillery resolver.
@@ -62,4 +58,3 @@
     </div>
 </div>
 {{ end }}
-{{ end }}

internal/dis/component/server/admin/admin.go

@@ -10,7 +10,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/exporter"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/exporter/logger"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/instances/purger"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/julienschmidt/httprouter"
 	"github.com/rs/zerolog"
 
@@ -32,7 +32,7 @@ type Admin struct {
 
 		Policy *policy.Policy
 
-		Templating *templates.Templating
+		Templating *templating.Templating
 
 		Purger *purger.Purger
 	}

internal/dis/component/server/admin/components.go

@@ -10,75 +10,71 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/instances"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
-	"github.com/FAU-CDI/wisski-distillery/internal/models"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
 	"github.com/FAU-CDI/wisski-distillery/pkg/lazy"
 	"github.com/julienschmidt/httprouter"
 )
 
-//go:embed "html/components.html"
+//go:embed "html/anal.html"
-var componentsHTML []byte
+var analHTML []byte
-var componentsTemplate = templates.Parse[componentContext]("components.html", componentsHTML, assets.AssetsAdmin)
+var analTemplate = templating.Parse[analContext](
+	"anal.html", analHTML, nil,
 
-type componentContext struct {
+	templating.Assets(assets.AssetsAdmin),
-	templates.BaseContext
+)
+
+type analContext struct {
+	templating.RuntimeFlags
 
 	Analytics lazy.PoolAnalytics
 }
 
 func (admin *Admin) components(ctx context.Context) http.Handler {
-	tpl := componentsTemplate.Prepare(admin.Dependencies.Templating, templates.BaseContextGaps{
+	tpl := analTemplate.Prepare(
-		Crumbs: []component.MenuItem{
+		admin.Dependencies.Templating,
-			{Title: "Admin", Path: "/admin/"},
+		templating.Crumbs(
-			{Title: "Components", Path: "/admin/components/"},
+			component.MenuItem{Title: "Admin", Path: "/admin/"},
-		},
+			component.MenuItem{Title: "Components", Path: "/admin/components/"},
-	})
+		),
+		templating.Title("Components"),
+	)
 
-	return tpl.HTMLHandler(func(r *http.Request) (cp componentContext, err error) {
+	return tpl.HTMLHandler(func(r *http.Request) (ac analContext, err error) {
-		cp.Analytics = *admin.Analytics
+		ac.Analytics = *admin.Analytics
 		return
 	})
 }
 
-//go:embed "html/ingredients.html"
-var ingredientsHTML []byte
-var ingredientsTemplate = templates.Parse[ingredientsContext]("ingredients.html", ingredientsHTML, assets.AssetsAdmin)
-
-type ingredientsContext struct {
-	templates.BaseContext
-
-	Instance  models.Instance
-	Analytics *lazy.PoolAnalytics
-}
-
 func (admin *Admin) ingredients(ctx context.Context) http.Handler {
-	tpl := ingredientsTemplate.Prepare(admin.Dependencies.Templating, templates.BaseContextGaps{
+	tpl := analTemplate.Prepare(
-		Crumbs: []component.MenuItem{
+		admin.Dependencies.Templating,
-			{Title: "Admin", Path: "/admin/"},
+		templating.Crumbs(
-			{Title: "Instance", Path: "* to be updated *"},
+			component.MenuItem{Title: "Admin", Path: "/admin/"},
-			{Title: "Ingredients", Path: "* to be updated *"},
+			component.DummyMenuItem,
-		},
+			component.DummyMenuItem,
-	})
+		),
+	)
 
-	return tpl.HTMLHandlerWithGaps(func(r *http.Request, gaps *templates.BaseContextGaps) (ic ingredientsContext, err error) {
+	return tpl.HTMLHandlerWithFlags(func(r *http.Request) (ac analContext, funcs []templating.FlagFunc, err error) {
 		slug := httprouter.ParamsFromContext(r.Context()).ByName("slug")
 
-		gaps.Crumbs[1] = component.MenuItem{Title: "Instance", Path: template.URL("/admin/instance/" + slug)}
-		gaps.Crumbs[2] = component.MenuItem{Title: "Ingredients", Path: template.URL("/admin/instance/" + slug + "/ingredients/")}
-
 		// find the instance itself!
 		instance, err := admin.Dependencies.Instances.WissKI(r.Context(), slug)
 		if err == instances.ErrWissKINotFound {
-			return ic, httpx.ErrNotFound
+			return ac, nil, httpx.ErrNotFound
 		}
 		if err != nil {
-			return ic, err
+			return ac, nil, err
+		}
+		funcs = []templating.FlagFunc{
+			templating.ReplaceCrumb(1, component.MenuItem{Title: "Instance", Path: template.URL("/admin/instance/" + slug)}),
+			templating.ReplaceCrumb(2, component.MenuItem{Title: "Ingredients", Path: template.URL("/admin/instance/" + slug + "/ingredients/")}),
+			templating.Title(instance.Name() + " - Ingredients"),
 		}
-		ic.Instance = instance.Instance
 
 		// and get the components
-		ic.Analytics = instance.Info().Analytics
+		ac.Analytics = *instance.Info().Analytics
 
 		return
 	})

internal/dis/component/server/admin/grants.go

@@ -10,7 +10,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/instances"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/internal/models"
 	"github.com/FAU-CDI/wisski-distillery/internal/wisski"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
@@ -22,10 +22,14 @@ import (
 
 //go:embed "html/grants.html"
 var grantsHTML []byte
-var grantsTemplate = templates.Parse[grantsContext]("grants.html", grantsHTML, assets.AssetsAdmin)
+var grantsTemplate = templating.Parse[grantsContext](
+	"grants.html", grantsHTML, nil,
+
+	templating.Assets(assets.AssetsAdmin),
+)
 
 type grantsContext struct {
-	templates.BaseContext
+	templating.RuntimeFlags
 
 	Error string
 
@@ -38,40 +42,43 @@ type grantsContext struct {
 }
 
 func (admin *Admin) grants(ctx context.Context) http.Handler {
-	tpl := grantsTemplate.Prepare(admin.Dependencies.Templating, templates.BaseContextGaps{
+	tpl := grantsTemplate.Prepare(
-		Crumbs: []component.MenuItem{
+		admin.Dependencies.Templating,
-			{Title: "Admin", Path: "/admin/"},
+		templating.Crumbs(
-			{Title: "Instance", Path: "*to be updated*"},
+			component.MenuItem{Title: "Admin", Path: "/admin/"},
-			{Title: "Grants", Path: "*to be updated*"},
+			component.DummyMenuItem,
-		},
+			component.DummyMenuItem,
-	})
+		),
+	)
 
-	return tpl.HTMLHandlerWithGaps(func(r *http.Request, gaps *templates.BaseContextGaps) (grantsContext, error) {
+	return tpl.HTMLHandlerWithFlags(func(r *http.Request) (grantsContext, []templating.FlagFunc, error) {
 		if r.Method == http.MethodGet {
-			return admin.getGrants(r, gaps)
+			return admin.getGrants(r)
 		} else {
-			return admin.postGrants(r, gaps)
+			return admin.postGrants(r)
 		}
 	})
 }
 
-func (admin *Admin) getGrants(r *http.Request, gaps *templates.BaseContextGaps) (gc grantsContext, err error) {
+func (admin *Admin) getGrants(r *http.Request) (gc grantsContext, funcs []templating.FlagFunc, err error) {
 	slug := httprouter.ParamsFromContext(r.Context()).ByName("slug")
-	if err := gc.use(r, gaps, slug, admin); err != nil {
+
-		return gc, err
+	funcs, err = gc.use(r, slug, admin)
+	if err != nil {
+		return gc, nil, err
 	}
 
 	if err := gc.useGrants(r, admin); err != nil {
-		return gc, err
+		return gc, nil, err
 	}
 
-	return gc, nil
+	return gc, funcs, nil
 }
 
-func (admin *Admin) postGrants(r *http.Request, gaps *templates.BaseContextGaps) (gc grantsContext, err error) {
+func (admin *Admin) postGrants(r *http.Request) (gc grantsContext, funcs []templating.FlagFunc, err error) {
 	// parse the form
 	if err := r.ParseForm(); err != nil {
-		return gc, err
+		return gc, nil, err
 	}
 
 	// read out the form values
@@ -84,15 +91,16 @@ func (admin *Admin) postGrants(r *http.Request, gaps *templates.BaseContextGaps)
 	)
 
 	// set the common fields
-	if err := gc.use(r, gaps, slug, admin); err != nil {
+	funcs, err = gc.use(r, slug, admin)
-		return gc, err
+	if err != nil {
+		return gc, nil, err
 	}
 
 	if delete {
 		// delete the user grant
 		err := admin.Dependencies.Policy.Remove(r.Context(), distilleryUser, slug)
 		if err != nil {
-			return gc, err
+			return gc, nil, err
 		}
 	} else {
 		// update the grant
@@ -110,26 +118,29 @@ func (admin *Admin) postGrants(r *http.Request, gaps *templates.BaseContextGaps)
 
 	// fetch the grants for the instance
 	if err := gc.useGrants(r, admin); err != nil {
-		return gc, err
+		return gc, nil, err
 	}
-	return gc, nil
+	return gc, funcs, nil
 }
 
-func (gc *grantsContext) use(r *http.Request, gaps *templates.BaseContextGaps, slug string, admin *Admin) (err error) {
+func (gc *grantsContext) use(r *http.Request, slug string, admin *Admin) (funcs []templating.FlagFunc, err error) {
-	gaps.Crumbs[1] = component.MenuItem{Title: "Instance", Path: template.URL("/admin/instance/" + slug)}
-	gaps.Crumbs[2] = component.MenuItem{Title: "Grants", Path: template.URL("/admin/instance/" + slug + "/grants/")}
-
 	// find the instance itself
 	gc.instance, err = admin.Dependencies.Instances.WissKI(r.Context(), slug)
 	if err == instances.ErrWissKINotFound {
-		return httpx.ErrNotFound
+		return nil, httpx.ErrNotFound
 	}
 	if err != nil {
-		return err
+		return nil, err
 	}
 	gc.Instance = gc.instance.Instance
 
-	return nil
+	// replace the functions
+	funcs = []templating.FlagFunc{
+		templating.ReplaceCrumb(1, component.MenuItem{Title: "Instance", Path: template.URL("/admin/instance/" + slug)}),
+		templating.ReplaceCrumb(2, component.MenuItem{Title: "Grants", Path: template.URL("/admin/instance/" + slug + "/grants/")}),
+		templating.Title(gc.Instance.Slug + " - Grants"),
+	}
+	return funcs, nil
 }
 
 func (gc *grantsContext) useGrants(r *http.Request, admin *Admin) (err error) {

internal/dis/component/server/admin/html/components.html

@@ -1,6 +0,0 @@
-{{ template "_base.html" . }}
-{{ define "title" }}Components{{ end }}
-
-{{ define "content" }}
-{{ template "_anal.html" .Analytics }}
-{{ end }}

internal/dis/component/server/admin/html/grants.html

@@ -1,7 +1,3 @@
-{{ template "_base.html" . }}
-{{ define "title" }}{{ .Instance.Slug }} - Grants{{ end }}
-
-{{ define "content" }}
 {{ $csrf := .CSRF }}
 {{ $slug := .Instance.Slug }}
 <div class="pure-u-1-1">
@@ -124,4 +120,3 @@
         <option value="{{ $drupal }}">
     {{ end }}
 </datalist>
-{{ end }}

internal/dis/component/server/admin/html/index.html

@@ -1,7 +1,3 @@
-{{ template "_base.html" . }}
-{{ define "title" }}Admin{{ end }}
-
-{{ define "content" }}
 <div class="pure-u-1-1">
     <h2 id="overview">Distillery Configuration</h2>
 </div>
@@ -257,4 +253,3 @@
     </div>
 </div>
 {{end}}
-{{ end }}

internal/dis/component/server/admin/html/ingredients.html

@@ -1,6 +0,0 @@
-{{ template "_base.html" . }}
-{{ define "title" }}{{ .Instance.Slug }} - Ingredients{{ end }}
-
-{{ define "content" }}
-{{ template "_anal.html" .Analytics }}
-{{ end }}

internal/dis/component/server/admin/html/instance.html

@@ -1,7 +1,3 @@
-{{ template "_base.html" . }}
-{{ define "title" }}{{ .Instance.Slug }}{{ end }}
-
-{{ define "content" }}
 <div class="pure-u-1-1">
     <h2 id="overview">Info &amp; Status</h2>
 </div>
@@ -485,4 +481,3 @@
         </fieldset>
     </form>
 </div>
-{{ end }}

internal/dis/component/server/admin/html/user_create.html

@@ -1,4 +1,2 @@
-{{ template "_form.html" . }}
+{{ template "form.html" . }}
-{{ define "form/title" }}Create User{{ end }}
 {{ define "form/button" }}Create{{ end }}
-

internal/dis/component/server/admin/html/users.html

@@ -1,8 +1,3 @@
-{{ template "_base.html" . }}
-{{ define "title" }}Users{{ end }}
-
-{{ define "content" }}
-
 <div class="pure-u-1">
     <div class="padding">
         <div class="overflow">
@@ -105,5 +100,3 @@
         </div>
     </div>
 </div>
-
-{{ end }}

internal/dis/component/server/admin/index.go

@@ -9,7 +9,7 @@ import (
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/internal/status"
 	"golang.org/x/sync/errgroup"
 )
@@ -80,27 +80,33 @@ func (admin *Admin) Fetch(flags component.FetcherFlags, target *status.Distiller
 
 //go:embed "html/index.html"
 var indexHTML []byte
-var indexTemplate = templates.Parse[indexContext]("index.html", indexHTML, assets.AssetsAdmin)
+var indexTemplate = templating.Parse[indexContext](
+	"index.html", indexHTML, nil,
+
+	templating.Title("Admin"),
+	templating.Assets(assets.AssetsAdmin),
+)
 
 type indexContext struct {
-	templates.BaseContext
+	templating.RuntimeFlags
 
 	status.Distillery
 	Instances []status.WissKI
 }
 
 func (admin *Admin) index(ctx context.Context) http.Handler {
-	tpl := indexTemplate.Prepare(admin.Dependencies.Templating, templates.BaseContextGaps{
+	tpl := indexTemplate.Prepare(
-		Crumbs: []component.MenuItem{
+		admin.Dependencies.Templating,
-			{Title: "Admin", Path: "/admin/"},
+		templating.Crumbs(
-		},
+			component.MenuItem{Title: "Admin", Path: "/admin/"},
-		Actions: []component.MenuItem{
+		),
-			{Title: "Users", Path: "/admin/users/"},
+		templating.Actions(
-			{Title: "Components", Path: "/admin/components/", Priority: component.SmallButton},
+			component.MenuItem{Title: "Users", Path: "/admin/users/"},
-		},
+			component.MenuItem{Title: "Components", Path: "/admin/components/", Priority: component.SmallButton},
-	})
+		),
+	)
 
-	return tpl.HTMLHandlerWithGaps(func(r *http.Request, gaps *templates.BaseContextGaps) (idx indexContext, err error) {
+	return tpl.HTMLHandler(func(r *http.Request) (idx indexContext, err error) {
 		idx.Distillery, idx.Instances, err = admin.Status(r.Context(), true)
 		return
 	})

internal/dis/component/server/admin/instance.go

@@ -9,7 +9,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/instances"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/internal/models"
 	"github.com/FAU-CDI/wisski-distillery/internal/status"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
@@ -18,49 +18,57 @@ import (
 
 //go:embed "html/instance.html"
 var instanceHTML []byte
-var instanceTemplate = templates.Parse[instanceContext]("instance.html", instanceHTML, assets.AssetsAdmin)
+var instanceTemplate = templating.Parse[instanceContext](
+	"instance.html", instanceHTML, nil,
+
+	templating.Assets(assets.AssetsAdmin),
+)
 
 type instanceContext struct {
-	templates.BaseContext
+	templating.RuntimeFlags
 
 	Instance models.Instance
 	Info     status.WissKI
 }
 
 func (admin *Admin) instance(ctx context.Context) http.Handler {
-	tpl := instanceTemplate.Prepare(admin.Dependencies.Templating, templates.BaseContextGaps{
+	tpl := instanceTemplate.Prepare(
-		Crumbs: []component.MenuItem{
+		admin.Dependencies.Templating,
-			{Title: "Admin", Path: "/admin/"},
+		templating.Crumbs(
-			{Title: "Instance", Path: "*to be replaced*"},
+			component.MenuItem{Title: "Admin", Path: "/admin/"},
-		},
+			component.DummyMenuItem,
-		Actions: []component.MenuItem{
+		),
-			{Title: "Grants", Path: "*to be replaced*"},
+		templating.Actions(
-			{Title: "Ingredients", Path: "*to be replaced*", Priority: component.SmallButton},
+			component.DummyMenuItem,
-		},
+			component.DummyMenuItem,
-	})
+		),
+	)
 
-	return tpl.HTMLHandlerWithGaps(func(r *http.Request, gaps *templates.BaseContextGaps) (ic instanceContext, err error) {
+	return tpl.HTMLHandlerWithFlags(func(r *http.Request) (ic instanceContext, funcs []templating.FlagFunc, err error) {
 		slug := httprouter.ParamsFromContext(r.Context()).ByName("slug")
 
-		gaps.Crumbs[1] = component.MenuItem{Title: "Instance", Path: template.URL("/admin/instance/" + slug)}
-
-		gaps.Actions[0] = component.MenuItem{Title: "Grants", Path: template.URL("/admin/grants/" + slug)}
-		gaps.Actions[1] = component.MenuItem{Title: "Ingredients", Path: template.URL("/admin/ingredients/" + slug), Priority: component.SmallButton}
-
 		// find the instance itself!
 		instance, err := admin.Dependencies.Instances.WissKI(r.Context(), slug)
 		if err == instances.ErrWissKINotFound {
-			return ic, httpx.ErrNotFound
+			return ic, nil, httpx.ErrNotFound
 		}
 		if err != nil {
-			return ic, err
+			return ic, nil, err
 		}
 		ic.Instance = instance.Instance
 
 		// get some more info about the wisski
 		ic.Info, err = instance.Info().Information(r.Context(), false)
 		if err != nil {
-			return ic, err
+			return ic, nil, err
+		}
+
+		funcs = []templating.FlagFunc{
+			templating.ReplaceCrumb(1, component.MenuItem{Title: "Instance", Path: template.URL("/admin/instance/" + slug)}),
+			templating.ReplaceAction(0, component.MenuItem{Title: "Grants", Path: template.URL("/admin/grants/" + slug)}),
+			templating.ReplaceAction(1, component.MenuItem{Title: "Ingredients", Path: template.URL("/admin/ingredients/" + slug), Priority: component.SmallButton}),
+
+			templating.Title(instance.Name()),
 		}
 
 		return

internal/dis/component/server/admin/users.go

@@ -11,7 +11,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/auth"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx/field"
 	"github.com/rs/zerolog"
@@ -19,25 +19,30 @@ import (
 
 //go:embed "html/users.html"
 var usersHTML []byte
-var usersTemplate = templates.Parse[usersContext]("user.html", usersHTML, assets.AssetsAdmin)
+var usersTemplate = templating.Parse[usersContext](
+	"users.html", usersHTML, nil,
+
+	templating.Title("Users"),
+	templating.Assets(assets.AssetsAdmin),
+)
 
 type usersContext struct {
-	templates.BaseContext
+	templating.RuntimeFlags
-
 	Error string
 	Users []*auth.AuthUser
 }
 
 func (admin *Admin) users(ctx context.Context) http.Handler {
-	tpl := usersTemplate.Prepare(admin.Dependencies.Templating, templates.BaseContextGaps{
+	tpl := usersTemplate.Prepare(
-		Crumbs: []component.MenuItem{
+		admin.Dependencies.Templating,
-			{Title: "Admin", Path: "/admin/"},
+		templating.Crumbs(
-			{Title: "Users", Path: "/admin/users/"},
+			component.MenuItem{Title: "Admin", Path: "/admin/"},
-		},
+			component.MenuItem{Title: "Users", Path: "/admin/users/"},
-		Actions: []component.MenuItem{
+		),
-			{Title: "Create New", Path: "/admin/users/create/"},
+		templating.Actions(
-		},
+			component.MenuItem{Title: "Create New", Path: "/admin/users/create/"},
-	})
+		),
+	)
 
 	return tpl.HTMLHandler(func(r *http.Request) (uc usersContext, err error) {
 		uc.Error = r.URL.Query().Get("error")
@@ -48,7 +53,12 @@ func (admin *Admin) users(ctx context.Context) http.Handler {
 
 //go:embed "html/user_create.html"
 var userCreateHTML []byte
-var userCreateTemplate = templates.ParseForm("user_create.html", userCreateHTML, assets.AssetsAdmin)
+var userCreateTemplate = templating.ParseForm(
+	"user_create.html", userCreateHTML, httpx.FormTemplate,
+
+	templating.Title("Create User"),
+	templating.Assets(assets.AssetsAdmin),
+)
 
 var (
 	errCreateInvalidUsername = errors.New("invalid username")
@@ -62,13 +72,14 @@ type createUserResult struct {
 }
 
 func (admin *Admin) createUser(ctx context.Context) http.Handler {
-	tpl := userCreateTemplate.Prepare(admin.Dependencies.Templating, templates.BaseContextGaps{
+	tpl := userCreateTemplate.Prepare(
-		Crumbs: []component.MenuItem{
+		admin.Dependencies.Templating,
-			{Title: "Admin", Path: "/admin/"},
+		templating.Crumbs(
-			{Title: "Users", Path: "/admin/users"},
+			component.MenuItem{Title: "Admin", Path: "/admin/"},
-			{Title: "Create", Path: "/admin/users/create"},
+			component.MenuItem{Title: "Users", Path: "/admin/users"},
-		},
+			component.MenuItem{Title: "Create", Path: "/admin/users/create"},
-	})
+		),
+	)
 
 	return &httpx.Form[createUserResult]{
 		Fields: []field.Field{
@@ -79,7 +90,7 @@ func (admin *Admin) createUser(ctx context.Context) http.Handler {
 		FieldTemplate: field.PureCSSFieldTemplate,
 
 		RenderTemplate:        tpl.Template(),
-		RenderTemplateContext: templates.FormTemplateContext(tpl),
+		RenderTemplateContext: templating.FormTemplateContext(tpl),
 
 		Validate: func(r *http.Request, values map[string]string) (cu createUserResult, err error) {
 			cu.User, cu.Passsword, cu.Admin = values["username"], values["password"], values["admin"] == field.CheckboxChecked

internal/dis/component/server/assets/assets.go

@@ -17,32 +17,8 @@ import (
 //
 // Each asset group should be registered as a parameter to the 'go:generate' line.
 type Assets struct {
-	Scripts string // <script> tags inserted by the asset
+	Scripts template.HTML // <script> tags inserted by the asset
-	Styles  string // <link> tags inserted by the asset
+	Styles  template.HTML // <link> tags inserted by the asset
 }
 
 //go:generate node build.mjs Default User Admin
-
-// MustParse parses a new template from the given source
-// and calls [RegisterAssoc] on it.
-func (assets *Assets) MustParse(t *template.Template, value string) *template.Template {
-	t = template.Must(t.Parse(value))
-	assets.RegisterAssoc(t)
-	return t
-}
-
-// MustParseShared is like [MustParse], but creates a new SharedTemplate instead
-func (assets *Assets) MustParseShared(name string, value string) *template.Template {
-	return assets.MustParse(NewSharedTemplate(name), value)
-}
-
-// RegisterAssoc registers two new associated templates with t.
-//
-// The template "scripts" will render all script tags required.
-// The template "styles" will render all style tags required.
-//
-// If either template already exists, it will be overwritten.
-func (assets *Assets) RegisterAssoc(t *template.Template) {
-	t.New("scripts").Parse(assets.Scripts)
-	t.New("styles").Parse(assets.Styles)
-}

internal/dis/component/server/assets/templates.go

@@ -1,23 +0,0 @@
-package assets
-
-import (
-	"embed"
-	"html/template"
-)
-
-//go:embed "templates/*.html"
-var templates embed.FS
-
-var (
-	shared *template.Template = template.Must(template.ParseFS(templates, "templates/*.html"))
-)
-
-// NewSharedTemplate creates a new template with the given name.
-// It will be able to make use of shared templates as well as functions.
-func NewSharedTemplate(name string) *template.Template {
-	new := template.New(name)
-	for _, template := range shared.Templates() {
-		new.AddParseTree(template.Tree.Name, template.Tree.Copy())
-	}
-	return new
-}

internal/dis/component/server/home/about.html

@@ -0,0 +1,5 @@
+<div class="pure-u-1">
+    <p>
+        For more information, see <a href="{{ .SelfRedirect }}">{{ .SelfRedirect }}</a>.
+    </p>
+</div>

internal/dis/component/server/home/home.go

@@ -7,7 +7,7 @@ import (
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/instances"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/internal/status"
 	"github.com/FAU-CDI/wisski-distillery/pkg/lazy"
 )
@@ -15,7 +15,7 @@ import (
 type Home struct {
 	component.Base
 	Dependencies struct {
-		Templating *templates.Templating
+		Templating *templating.Templating
 		Instances  *instances.Instances
 	}
 

internal/dis/component/server/home/public.go

@@ -3,41 +3,73 @@ package home
 import (
 	"context"
 	_ "embed"
+	"html/template"
 	"net/http"
 	"strings"
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/internal/status"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
 )
 
 //go:embed "public.html"
 var publicHTML []byte
-var publicTemplate = templates.Parse[publicContext]("public.html", publicHTML, assets.AssetsDefault)
+var publicTemplate = templating.Parse[publicContext](
+	"public.html", publicHTML, nil,
 
-type publicContext struct {
+	templating.Title("WissKI Distillery"),
-	templates.BaseContext
+	templating.Assets(assets.AssetsDefault),
+)
 
+//go:embed "about.html"
+var aboutHTML string
+var aboutTemplate = template.Must(template.New("about.html").Parse(aboutHTML))
+
+// aboutContext is passed to about.html
+type aboutContext struct {
 	Instances    []status.WissKI
 	SelfRedirect string
 }
 
+// publicCOntext is passed to public.html
+type publicContext struct {
+	templating.RuntimeFlags
+
+	aboutContext
+	About template.HTML
+}
+
 func (home *Home) publicHandler(ctx context.Context) http.Handler {
-	tpl := publicTemplate.Prepare(home.Dependencies.Templating, templates.BaseContextGaps{
+
-		Crumbs: []component.MenuItem{
+	tpl := publicTemplate.Prepare(
-			{Title: "WissKI Distillery", Path: "/"},
+		home.Dependencies.Templating,
-		},
+		templating.Crumbs(
-	})
+			component.MenuItem{Title: "WissKI Distillery", Path: "/"},
+		),
+	)
+
+	about := home.Dependencies.Templating.GetCustomizable(aboutTemplate)
+
 	return tpl.HTMLHandler(func(r *http.Request) (pc publicContext, err error) {
 		// only act on the root path!
 		if strings.TrimSuffix(r.URL.Path, "/") != "" {
 			return pc, httpx.ErrNotFound
 		}
 
-		pc.Instances = home.homeInstances.Get(nil)
+		// prepare about
-		pc.SelfRedirect = home.Config.SelfRedirect.String()
+		pc.aboutContext.Instances = home.homeInstances.Get(nil)
+		pc.aboutContext.SelfRedirect = home.Config.SelfRedirect.String()
+
+		// render the about template
+		var builder strings.Builder
+		if err := about.Execute(&builder, pc.aboutContext); err != nil {
+			return pc, nil
+		}
+
+		// and return about!
+		pc.About = template.HTML(builder.String())
 
 		return
 	})

internal/dis/component/server/home/public.html

@@ -1,14 +1,4 @@
-{{ template "_base.html" . }}
+{{ .About }}
-{{ define "title" }}WissKI Distillery{{ end }}
-
-{{ define "content" }}
-{{ block "@custom/about" . }}
-<div class="pure-u-1">
-    <p>
-        For more information, see <a href="{{ .SelfRedirect }}">{{ .SelfRedirect }}</a>.
-    </p>
-</div>
-{{ end }}
 
 <div class="pure-u-1">
     <h2>WissKIs on this Distillery</h2>
@@ -33,4 +23,3 @@
         </div>
     {{ end }}
 {{ end }}
-{{ end }}

internal/dis/component/server/legal/legal.go

@@ -8,7 +8,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 
 	_ "embed"
 )
@@ -17,7 +17,7 @@ type Legal struct {
 	component.Base
 	Dependencies struct {
 		Static     *assets.Static
-		Templating *templates.Templating
+		Templating *templating.Templating
 	}
 }
 
@@ -27,10 +27,15 @@ var (
 
 //go:embed "legal.html"
 var legalHTML []byte
-var legalTemplate = templates.Parse[legalContext]("legal.html", legalHTML, assets.AssetsDefault)
+var legalTemplate = templating.Parse[legalContext](
+	"legal.html", legalHTML, nil,
+
+	templating.Title("Legal"),
+	templating.Assets(assets.AssetsDefault),
+)
 
 type legalContext struct {
-	templates.BaseContext
+	templating.RuntimeFlags
 
 	LegalNotices string
 
@@ -49,11 +54,12 @@ func (legal *Legal) Routes() component.Routes {
 }
 
 func (legal *Legal) HandleRoute(ctx context.Context, route string) (http.Handler, error) {
-	tpl := legalTemplate.Prepare(legal.Dependencies.Templating, templates.BaseContextGaps{
+	tpl := legalTemplate.Prepare(
-		Crumbs: []component.MenuItem{
+		legal.Dependencies.Templating,
-			{Title: "Legal", Path: "/legal/"},
+		templating.Crumbs(
-		},
+			component.MenuItem{Title: "Legal", Path: "/legal/"},
-	})
+		),
+	)
 
 	return tpl.HTMLHandler(func(r *http.Request) (lc legalContext, err error) {
 		lc.LegalNotices = cli.LegalNotices

internal/dis/component/server/legal/legal.html

@@ -1,7 +1,3 @@
-{{ template "_base.html" . }}
-{{ define "title" }}Legal{{ end }}
-
-{{ define "content" }}
 <div class="pure-u-1">
     <h2 id="cookies">Cookie Usage</h2>
 
@@ -69,4 +65,3 @@
 
     <pre>{{ .AssetsDisclaimer }}</pre>
 </div>
-{{ end }}

internal/dis/component/server/news/news.go

@@ -11,7 +11,7 @@ import (
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/rs/zerolog"
 	"github.com/yuin/goldmark"
 	gmmeta "github.com/yuin/goldmark-meta"
@@ -22,7 +22,7 @@ import (
 type News struct {
 	component.Base
 	Dependencies struct {
-		Templating *templates.Templating
+		Templating *templating.Templating
 	}
 }
 
@@ -113,20 +113,26 @@ func Items() ([]Item, error) {
 
 //go:embed "news.html"
 var newsHTML []byte
-var newsTemplate = templates.Parse[newsContext]("news.html", newsHTML, assets.AssetsDefault)
+var newsTemplate = templating.Parse[newsContext](
+	"news.html", newsHTML, nil,
+
+	templating.Title("News"),
+	templating.Assets(assets.AssetsDefault),
+)
 
 type newsContext struct {
-	templates.BaseContext
+	templating.RuntimeFlags
 	Items []Item
 }
 
 // HandleRoute returns the handler for the requested path
 func (news *News) HandleRoute(ctx context.Context, path string) (http.Handler, error) {
-	tpl := newsTemplate.Prepare(news.Dependencies.Templating, templates.BaseContextGaps{
+	tpl := newsTemplate.Prepare(
-		Crumbs: []component.MenuItem{
+		news.Dependencies.Templating,
-			{Title: "News", Path: "/news/"},
+		templating.Crumbs(
-		},
+			component.MenuItem{Title: "News", Path: "/news/"},
-	})
+		),
+	)
 
 	items, itemsErr := Items()
 	if itemsErr != nil {

internal/dis/component/server/news/news.html

@@ -1,8 +1,3 @@
-{{ template "_base.html" . }}
-{{ define "title" }}News{{ end }}
-
-{{ define "content" }}
-
 <div class="pure-u-1">
     This page contains news items from the distillery.
 </div>
@@ -14,5 +9,3 @@
         {{ .Content }}
     </div>
 {{ end }}
-
-{{ end }}

internal/dis/component/server/server.go

@@ -7,7 +7,7 @@ import (
 	"net/http"
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/pkg/cancel"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
 	"github.com/FAU-CDI/wisski-distillery/pkg/mux"
@@ -22,7 +22,7 @@ type Server struct {
 		Routeables []component.Routeable
 		Cronables  []component.Cronable
 
-		Templating *templates.Templating
+		Templating *templating.Templating
 	}
 }
 

internal/dis/component/server/templates/context.go

@@ -1,102 +0,0 @@
-package templates
-
-import (
-	"html/template"
-	"net/http"
-	"reflect"
-	"time"
-
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
-	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
-	"github.com/gorilla/csrf"
-	"github.com/tkw1536/goprogram/lib/reflectx"
-	"golang.org/x/exp/slices"
-)
-
-// baseContextName is the name of the [BaseContext] type
-var baseContextName = reflectx.TypeOf[BaseContext]().Name()
-
-// BaseContext represents a context used by templates
-//
-// Other invocations might cause an error at runtime.
-type BaseContext struct {
-	inited        bool // has this context been inited?
-	requestWasNil bool // was the passed request nil
-
-	GeneratedAt time.Time // time this page was generated at
-
-	// Menu and breadcrumbs
-	Menu []component.MenuItem
-	BaseContextGaps
-
-	CSRF template.HTML // CSRF Field
-}
-
-// constants that are used in various parts of the template to render stuff
-const (
-	errorPrefix template.HTML = `<div style="z-index:10000;position:fixed;top:0;left:0;width:100vh;height:100vw;background:red;text-align:center;padding:10vh 10vw;font-size:xx-large;font-weight:bold">`
-	errorSuffix template.HTML = "</div>"
-
-	csrfError       template.HTML = errorPrefix + "CSRF used but not provided" + errorSuffix
-	initError       template.HTML = errorPrefix + "<code>BaseContext.use()</code> not called" + errorSuffix
-	requestNilError template.HTML = errorPrefix + "<code>BaseContext.use()</code> called with nil request" + errorSuffix
-)
-
-type BaseContextGaps struct {
-	Crumbs  []component.MenuItem
-	Actions []component.MenuItem
-}
-
-func (bcg BaseContextGaps) clone() BaseContextGaps {
-	return BaseContextGaps{
-		Crumbs:  slices.Clone(bcg.Crumbs),
-		Actions: slices.Clone(bcg.Actions),
-	}
-}
-
-// update updates an embedded BaseContext field in context.
-func (tpl *Templating) update(context any, r *http.Request, bcg BaseContextGaps) *BaseContext {
-	tc := reflect.ValueOf(context).
-		Elem().FieldByName(baseContextName).Addr().
-		Interface().(*BaseContext)
-
-	tc.inited = true
-	tc.requestWasNil = r == nil
-
-	tc.GeneratedAt = time.Now().UTC()
-
-	// setup the CSRF field
-	tc.CSRF = csrfError
-	if r != nil {
-		tc.CSRF = csrf.TemplateField(r)
-	}
-
-	// build the menu
-	tc.Menu = tpl.buildMenu(r)
-
-	// build the breadcrumbs
-	tc.BaseContextGaps = bcg.clone()
-	last := len(tc.Crumbs) - 1
-	for i := range tc.Crumbs {
-		tc.Crumbs[i].Active = i == last
-	}
-
-	return tc
-}
-
-// DoInitCheck is called by the template to check that the BaseContext was initialized properly
-func (bc BaseContext) DoInitCheck() template.HTML {
-	if !bc.inited {
-		return initError
-	}
-	if bc.requestWasNil {
-		return requestNilError
-	}
-	return ""
-}
-
-// BaseFormContext combines BaseContext and FormContext
-type BaseFormContext struct {
-	BaseContext
-	httpx.FormContext
-}

internal/dis/component/server/templates/new.go

@@ -1,139 +0,0 @@
-package templates
-
-import (
-	"html/template"
-	"net/http"
-
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
-	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
-)
-
-// Parsed represents a parsed template that receives an underlying context of type C
-type Parsed[C any] struct {
-	template *template.Template
-}
-
-// Parse creates a new Parsed from a template source.
-// Parse calls panic() when parsing fails.
-func Parse[C any](name string, source []byte, Assets assets.Assets) Parsed[C] {
-	return Parsed[C]{
-		template: Assets.MustParseShared(name, string(source)),
-	}
-}
-
-// Prepare prepares this template for use inside a concrete handler.
-// gaps must either be of length 0 or length 1 and may pre-fill gaps to be used when executing the template later.
-func (p *Parsed[C]) Prepare(tpl *Templating, gaps ...BaseContextGaps) *Template[C] {
-	wrap := Template[C]{
-		tpl:      tpl,
-		template: tpl.Template(p.template),
-	}
-	if len(gaps) > 1 {
-		panic("WrapTemplate: must provide either 1 or no gaps")
-	}
-	if len(gaps) == 1 {
-		wrap.gaps = gaps[0]
-	}
-	return &wrap
-}
-
-// Tempalte represents an executable template.
-type Template[C any] struct {
-	tpl      *Templating
-	template *template.Template
-	gaps     BaseContextGaps
-}
-
-// Template returns a template that, if executed together with the context by the Context method, produces the desired result.
-func (tw *Template[C]) Template() *template.Template {
-	return tw.template
-}
-
-// Context generates a context for a given request that can be used to execute the provided template.
-func (tw *Template[C]) Context(r *http.Request, c C, gaps ...BaseContextGaps) any {
-	// make the gaps something
-	if len(gaps) > 1 {
-		panic("Context: must provide either 1 or no gaps")
-	}
-
-	// update the context with gaps
-	{
-		g := tw.gaps
-		if len(gaps) == 1 {
-			g = gaps[0]
-		}
-		tw.tpl.update(&c, r, g)
-	}
-
-	return c
-}
-
-// ParseForm is like Parse[BaseFormContext]
-var ParseForm = Parse[BaseFormContext]
-
-// FormTemplateContext returns a new handler for a form with the given base context
-func FormTemplateContext(tw *Template[BaseFormContext]) func(ctx httpx.FormContext, r *http.Request) any {
-	return func(ctx httpx.FormContext, r *http.Request) any {
-		return tw.Context(r, BaseFormContext{FormContext: ctx})
-	}
-}
-
-// MappedHandler returns a new handler that maps the incoming context via f
-func MappedHandler[In, Out any](tw *Template[Out], f func(ctx In, r *http.Request) (Out, BaseContextGaps)) func(ctx In, r *http.Request) any {
-	// TODO: Should this one be removed?
-	return func(ctx In, r *http.Request) any {
-		c, g := f(ctx, r)
-		return tw.Context(r, c, g)
-	}
-}
-
-// Hander returns a function that returns a context for the given template
-func (tw *Template[C]) Handler(f func(r *http.Request) (C, error)) func(r *http.Request) (any, error) {
-	// TODO: Should this one be removed?
-	return tw.HandlerWithGaps(func(r *http.Request, gaps *BaseContextGaps) (C, error) {
-		return f(r)
-	})
-}
-
-// HTMLHandler returns a new HTMLHandler for this request
-func (tw *Template[C]) HTMLHandler(f func(r *http.Request) (C, error)) httpx.HTMLHandler[any] {
-	return httpx.HTMLHandler[any]{
-		Handler:  tw.Handler(f),
-		Template: tw.Template(),
-	}
-}
-
-// HandlerWithGaps works like handler, but additionally receives a gaps object to update.
-func (tw *Template[C]) HandlerWithGaps(f func(r *http.Request, gaps *BaseContextGaps) (C, error)) func(r *http.Request) (any, error) {
-	// TODO: Drop this variant?
-	var zero C
-	return func(r *http.Request) (any, error) {
-		g := tw.gaps.clone()
-		c, err := f(r, &g)
-		if err != nil {
-			return zero, err
-		}
-
-		// update the context
-		return tw.Context(r, c, g), nil
-	}
-}
-
-func (tw *Template[C]) HTMLHandlerWithGaps(f func(r *http.Request, gaps *BaseContextGaps) (C, error)) httpx.HTMLHandler[any] {
-	return httpx.HTMLHandler[any]{
-		Handler:  tw.HandlerWithGaps(f),
-		Template: tw.Template(),
-	}
-}
-
-// Execute executes this template with the given context
-func (tw *Template[C]) Execute(w http.ResponseWriter, r *http.Request, c C, gaps ...BaseContextGaps) error {
-	return tw.ExecuteWithError(w, r, c, nil, gaps...)
-}
-
-// ExecuteWithError executes this template, or the default error handler if err != nil
-func (tw *Template[C]) ExecuteWithError(w http.ResponseWriter, r *http.Request, c C, err error, gaps ...BaseContextGaps) error {
-	// TODO: Drop this variant?
-	// TODO: This should be removed!
-	return httpx.WriteHTML(tw.Context(r, c, gaps...), err, tw.template, "", w, r)
-}

internal/dis/component/server/templates/template.go

@@ -1,65 +0,0 @@
-package templates
-
-import (
-	_ "embed"
-	"html/template"
-	"text/template/parse"
-
-	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
-)
-
-const (
-	footerName = "@custom/footer"
-	aboutName  = "@custom/about"
-)
-
-//go:embed "footer.html"
-var footerTemplateStr string
-var defaultFooterTemplate = template.Must(template.New("footer.html").Parse(footerTemplateStr))
-
-// Template creates a copy of template with shared template parts updated accordingly.
-// Any template using this should use one of the template contexts in this package.
-func (tpl *Templating) Template(t *template.Template) *template.Template {
-	// TODO: This should not be used!
-
-	// create a clone of the template
-	clone := template.Must(t.Clone())
-
-	// add all the fixed parse trees
-	footerTree := tpl.getTemplateAsset(defaultFooterTemplate)
-	template.Must(clone.AddParseTree(footerName, footerTree))
-
-	// optionally add the about asset
-	if aboutTree := tpl.readTemplateAsset("about.html"); clone.Lookup(aboutName) != nil && aboutTree != nil {
-		template.Must(clone.AddParseTree(aboutName, aboutTree))
-	}
-	return clone // and return the tree
-}
-
-// getTemplateAsset returns an overridable template asset.
-//
-// If the asset named can successfully be parsed, it is returned.
-// If it can not be parsed, the default template is returned.
-func (tpl *Templating) getTemplateAsset(dflt *template.Template) *parse.Tree {
-	tree := tpl.readTemplateAsset(dflt.Name())
-	if tree == nil {
-		return dflt.Tree.Copy()
-	}
-	return tree
-}
-
-// readTemplateAsset is like getTemplateAssets, but takes an explicit name to read.
-// when the asset does not exist, or cannot be opened, returns nil.
-func (tpl *Templating) readTemplateAsset(name string) *parse.Tree {
-	template, err := (func() (*template.Template, error) {
-		data, err := environment.ReadFile(tpl.Environment, tpl.CustomAssetPath(name))
-		if err != nil {
-			return nil, err
-		}
-		return template.New(name).Parse(string(data))
-	})()
-	if err != nil {
-		return nil
-	}
-	return template.Tree
-}

internal/dis/component/server/templating/assets.go

@@ -1,4 +1,4 @@
-package templates
+package templating
 
 import (
 	"path/filepath"

internal/dis/component/server/templating/base.go

@@ -0,0 +1,193 @@
+package templating
+
+import (
+	"context"
+	_ "embed"
+	"fmt"
+	"html/template"
+	"net/http"
+	"reflect"
+	"strings"
+	"time"
+
+	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
+	"github.com/gorilla/csrf"
+	"github.com/rs/zerolog"
+)
+
+//go:embed "src/base.html"
+var baseHTML string
+var baseTemplate = template.Must(template.New("base.html").Parse(baseHTML))
+
+// Tempalte represents an executable template.
+type Template[C any] struct {
+	templating *Templating
+	p          *Parsed[C]
+}
+
+// Template returns a template that, if executed together with the context by the Context method, produces the desired result.
+func (tpl *Template[C]) Template() *template.Template {
+	return baseTemplate
+}
+
+// Context generates the context to pass to an instance of the template returned by Template.
+func (tpl *Template[C]) Context(r *http.Request, c C, funcs ...FlagFunc) (ctx *tContext[C]) {
+	// create a new context
+	ctx = new(tContext[C])
+
+	// setup the basic properties
+	ctx.ctx = r.Context()
+	ctx.Runtime.RequestURI = r.URL.RequestURI()
+	ctx.Runtime.GeneratedAt = time.Now().UTC()
+	ctx.Runtime.CSRF = csrf.TemplateField(r)
+	ctx.Runtime.Menu = tpl.templating.buildMenu(r)
+
+	// generate the rest of the options
+	ctx.Runtime.Flags = ctx.Runtime.Flags.Apply(r, tpl.p.funcs...)
+	ctx.Runtime.Flags = ctx.Runtime.Flags.Apply(r, funcs...)
+
+	// if the context has a runtime flags embed, then set the field properly
+	if tpl.p.hasRuntimeFlagsEmbed {
+		reflect.ValueOf(&c).Elem().
+			FieldByName(runtimeFlagsName).
+			Set(reflect.ValueOf(ctx.Runtime))
+	}
+
+	// the main template
+	ctx.cMain = c
+	ctx.tMain = tpl.p.tpl
+
+	// the footer template
+	ctx.tFooter = tpl.templating.GetCustomizable(footerTemplate)
+	ctx.cFooter = ctx.Runtime
+
+	return
+}
+
+// ParseForm is like Parse[BaseFormContext]
+var ParseForm = Parse[FormContext]
+
+type FormContext struct {
+	httpx.FormContext
+	RuntimeFlags
+}
+
+// NewFormContext returns a new FormContext from an underlying context
+func NewFormContext(context httpx.FormContext) FormContext {
+	return FormContext{FormContext: context}
+}
+
+// FormTemplateContext returns a new handler for a form with the given base context
+func FormTemplateContext(tw *Template[FormContext]) func(ctx httpx.FormContext, r *http.Request) any {
+	// TODO: Is this needed?
+	return func(ctx httpx.FormContext, r *http.Request) any {
+		return tw.Context(r, FormContext{FormContext: ctx})
+	}
+}
+
+// Hander returns a function that returns a context for the given template
+func (tw *Template[C]) Handler(f func(r *http.Request) (C, error)) func(r *http.Request) (any, error) {
+	// TODO: Should this one be removed?
+	return tw.HandlerWithFlags(func(r *http.Request) (C, []FlagFunc, error) {
+		c, err := f(r)
+		return c, nil, err
+	})
+}
+
+// HTMLHandler returns a new HTMLHandler for this request
+func (tw *Template[C]) HTMLHandler(f func(r *http.Request) (C, error)) httpx.HTMLHandler[any] {
+	return httpx.HTMLHandler[any]{
+		Handler:  tw.Handler(f),
+		Template: tw.Template(),
+	}
+}
+
+// HandlerWithFlags works like handler, but additionally receive funcs to generate flags
+func (tw *Template[C]) HandlerWithFlags(f func(r *http.Request) (C, []FlagFunc, error)) func(r *http.Request) (any, error) {
+	return func(r *http.Request) (any, error) {
+		c, funcs, err := f(r)
+		if err != nil {
+			return nil, err
+		}
+
+		return tw.Context(r, c, funcs...), nil
+	}
+}
+
+func (tw *Template[C]) HTMLHandlerWithFlags(f func(r *http.Request) (C, []FlagFunc, error)) httpx.HTMLHandler[any] {
+	return httpx.HTMLHandler[any]{
+		Handler:  tw.HandlerWithFlags(f),
+		Template: tw.Template(),
+	}
+}
+
+// tContext is passed to the underlying template.
+//
+// Callers may not retain references beyond the invocation of the template.
+// Callers must not rely on the internal structure of this tContext.
+type tContext[C any] struct {
+	Runtime RuntimeFlags // underlying flags
+
+	ctx context.Context // underlying context for render
+
+	// the main template and context
+	tMain *template.Template
+	cMain C
+
+	// the footer template and context
+	tFooter *template.Template
+	cFooter RuntimeFlags
+}
+
+// Main renders the main template.
+func (ctx *tContext[C]) Main() (template.HTML, error) {
+	return ctx.renderSafe("main", ctx.tMain, ctx.cMain)
+}
+
+// Footer renders the footer template
+func (ctx *tContext[C]) Footer() (template.HTML, error) {
+	return ctx.renderSafe("footer", ctx.tFooter, ctx.cFooter)
+}
+
+const renderSafeError = "Error displaying page. See server log for details. "
+
+func (ctx *tContext[C]) renderSafe(name string, t *template.Template, c any) (template.HTML, error) {
+
+	// already done
+	if err := ctx.ctx.Err(); err != nil {
+		return "", err
+	}
+
+	value, err, panicked := func() (value template.HTML, err error, panicked bool) {
+		var builder strings.Builder
+
+		defer func() {
+			if panicked {
+				r := recover()
+				zerolog.Ctx(ctx.ctx).Error().
+					Str("uri", ctx.Runtime.RequestURI).
+					Str("name", name).
+					Str("panic", fmt.Sprint(r)).
+					Msg("templating.Main(): template panic()ed")
+			}
+		}()
+
+		panicked = true
+		err = t.Execute(&builder, c)
+		panicked = false
+
+		if err != nil {
+			zerolog.Ctx(ctx.ctx).Err(err).
+				Str("uri", ctx.Runtime.RequestURI).
+				Str("name", name).
+				Msg("template errored")
+		}
+
+		return template.HTML(builder.String()), err, false
+	}()
+
+	if err != nil || panicked {
+		return renderSafeError, httpx.ErrInternalServerError
+	}
+	return value, nil
+}

internal/dis/component/server/templating/flags.go

@@ -0,0 +1,101 @@
+package templating
+
+import (
+	"html/template"
+	"net/http"
+	"time"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/assets"
+	"github.com/tkw1536/goprogram/lib/reflectx"
+	"golang.org/x/exp/slices"
+)
+
+// Flags represent handle-updatable options for the base template
+type Flags struct {
+	Title         string // Title of the menu
+	assets.Assets        // assets are the assets included in the template
+
+	Crumbs  []component.MenuItem // crumbs are the breadcrumbs leading to a specific action
+	Actions []component.MenuItem // actions are the actions available to a specific thingy
+}
+
+// Apply applies a set of functions to this flags
+func (flags Flags) Apply(r *http.Request, funcs ...FlagFunc) Flags {
+	for _, f := range funcs {
+		flags = f(flags, r)
+	}
+	return flags
+}
+
+// RuntimeFlags are passed to the template at runtime.
+// Any context may e
+type RuntimeFlags struct {
+	Flags
+
+	RequestURI  string               // request uri of the current page
+	Menu        []component.MenuItem // menu at the top of the page
+	GeneratedAt time.Time            // time the underlying data returned
+	CSRF        template.HTML        // csrf data (if any)
+}
+
+var runtimeFlagsName = reflectx.TypeOf[RuntimeFlags]().Name()
+
+// Clone clones this flags
+func (flags Flags) Clone() Flags {
+	flags.Crumbs = slices.Clone(flags.Crumbs)
+	flags.Actions = slices.Clone(flags.Actions)
+	return flags
+}
+
+// FlagFunc updates a flags based on a request.
+// FlagFunc may not be nil.
+type FlagFunc func(flags Flags, r *http.Request) Flags
+
+// Assets sets the given assets for the given flags
+func Assets(Assets assets.Assets) FlagFunc {
+	return func(flags Flags, r *http.Request) Flags {
+		flags.Assets = Assets
+		return flags
+	}
+}
+
+// Crumbs sets the crumbs
+func Crumbs(crumbs ...component.MenuItem) FlagFunc {
+	return func(flags Flags, r *http.Request) Flags {
+		flags.Crumbs = crumbs
+		return flags
+	}
+}
+
+// Actions sets the actions
+func Actions(actions ...component.MenuItem) FlagFunc {
+	return func(flags Flags, r *http.Request) Flags {
+		flags.Actions = actions
+		return flags
+	}
+}
+
+// ReplaceAction replaces a specific action
+func ReplaceAction(index int, action component.MenuItem) FlagFunc {
+	return func(flags Flags, r *http.Request) Flags {
+		flags.Actions[index] = action
+		return flags
+	}
+}
+
+// ReplaceCrumb replaces a specific crum
+func ReplaceCrumb(index int, action component.MenuItem) FlagFunc {
+	return func(flags Flags, r *http.Request) Flags {
+		flags.Crumbs[index] = action
+		return flags
+	}
+}
+
+// Title sets the title of this template
+func Title(title string) FlagFunc {
+	return func(flags Flags, r *http.Request) Flags {
+		flags.Title = title
+		return flags
+	}
+}

internal/dis/component/server/templating/menu.go

@@ -1,4 +1,4 @@
-package templates
+package templating
 
 import (
 	"html/template"

internal/dis/component/server/templating/parse.go

@@ -0,0 +1,66 @@
+package templating
+
+import (
+	"html/template"
+	"reflect"
+
+	"github.com/tkw1536/goprogram/lib/reflectx"
+	"golang.org/x/exp/slices"
+)
+
+// Parsed represents a parsed template that takes as argument a context of type C.
+type Parsed[C any] struct {
+	// does the context type an embed of the runtime flags type?
+	hasRuntimeFlagsEmbed bool
+
+	tpl   *template.Template // parsed template
+	funcs []FlagFunc         // optionally concfigured functions.
+}
+
+// Parse parses a template with the given name and source.
+// If base is not nil, every template associated with the base template is copied into the given template.
+// Functions will be applied on creation time to represent the context for the given template.
+func Parse[C any](name string, source []byte, base *template.Template, funcs ...FlagFunc) Parsed[C] {
+	tp := reflectx.TypeOf[C]()
+
+	// determine if we have an embedded field in the struct
+	var hasEmbed bool
+	if tp.Kind() == reflect.Struct {
+		field, ok := tp.FieldByName(runtimeFlagsName)
+		if ok {
+			hasEmbed = field.Anonymous
+		}
+	}
+
+	// create a new template, and optionally inherit from the base template
+	new := template.New(name)
+	if base != nil {
+		for _, tree := range base.Templates() {
+			root := tree.Tree.Copy()
+			new.AddParseTree(tree.Name(), root)
+		}
+	}
+
+	return Parsed[C]{
+		hasRuntimeFlagsEmbed: hasEmbed,
+		tpl:                  template.Must(new.Parse(string(source))),
+		funcs:                funcs,
+	}
+}
+
+// Prepare prepares this template to be used with the given templating.
+func (p *Parsed[C]) Prepare(templating *Templating, funcs ...FlagFunc) *Template[C] {
+	pcopy := *p // make a copy of p!
+
+	wrap := Template[C]{
+		templating: templating,
+
+		p: &pcopy,
+	}
+
+	// copy the functions!
+	pcopy.funcs = slices.Clone(pcopy.funcs)
+	pcopy.funcs = append(wrap.p.funcs, funcs...)
+
+	return &wrap
+}

internal/dis/component/server/templating/src/base.html

@@ -4,15 +4,14 @@
         <meta name="viewport" content="width=device-width, initial-scale=1">
         <meta charset="utf-8">
 
-        <title>{{ block "title" . }}WissKI Distillery{{ end }}</title>
+        <title>{{ .Runtime.Flags.Title }}</title>
-        {{ block "styles" . }}styles{{ end }}
+        {{ .Runtime.Flags.Assets.Styles }}
     </head>
 
     <body>
-        {{ .BaseContext.DoInitCheck }}
         <nav class="pure-menu pure-menu-horizontal">
             <ul class="pure-menu-list" role="menubar">
-                {{ range .BaseContext.Menu }}
+                {{ range .Runtime.Menu }}
                 <li class="pure-menu-item{{ if .Active }} pure-menu-selected{{ end }}">
                     <a href="{{ .Path }}" class="pure-menu-link">{{ .Title }}</a>
                 </li>
@@ -20,16 +19,16 @@
             </ul>
         </nav>
         <nav class="breadcrumbs" role="navigation" aria-label="Breadcrumbs">
-            {{ range .BaseContext.Crumbs }}
+            {{ range .Runtime.Flags.Crumbs }}
                 <a class="{{ if .Active }}active{{ end }}" href="{{ .Path }}">{{ .Title }}</a>
             {{ end }}
         </nav>
 
         <header>
-            <h1 id="top">{{ template "title" . }}</h1>
+            <h1 id="top">{{ .Runtime.Flags.Title }}</h1>
-            {{ if .BaseContext.Actions }}
+            {{ if .Runtime.Flags.Actions }}
                 <div class="pure-button-group" role="group" aria-label="Actions">
-                    {{ range .BaseContext.Actions }}
+                    {{ range .Runtime.Flags.Actions }}
                         <a href="{{ .Path }}" class="pure-button{{ if eq .Priority -1 }} pure-button-small{{end}}">{{ .Title }}</a>
                     {{ end }}
                 </div>
@@ -37,20 +36,16 @@
         </header>
         <main>
             <div class="pure-g">
-                {{ block "content" . }}content{{ end }}
+                {{ .Main }}
             </div>
         </main>
 
         <footer>
-            {{ block "@custom/footer" .BaseContext }}
+            {{ .Footer }}
-            <div style="z-index:10000;position:fixed;top:0;left:0;width:100vh;height:100vw;background:red;text-align:center;padding:10vh 10vw;font-size:xx-large;font-weight:bold">
-                <code>.Templating.Template()</code> not called
-            </div>
-            {{ end }}
         </footer>
 
 
-        {{ block "scripts" . }}scripts{{ end }}
+        {{ .Runtime.Flags.Assets.Scripts }}
     </body>
 
 </html>

internal/dis/component/server/templating/template.go

@@ -0,0 +1,29 @@
+package templating
+
+import (
+	_ "embed"
+	"html/template"
+
+	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
+)
+
+//go:embed "src/footer.html"
+var footerHTML string
+var footerTemplate = template.Must(template.New("footer.html").Parse(footerHTML))
+
+// GetCustomizable returns either a clone of dflt, or the overriden template with the same name.
+func (tpl *Templating) GetCustomizable(dflt *template.Template) *template.Template {
+	name := dflt.Name()
+
+	custom, err := (func() (*template.Template, error) {
+		data, err := environment.ReadFile(tpl.Environment, tpl.CustomAssetPath(name))
+		if err != nil {
+			return nil, err
+		}
+		return template.New(name).Parse(string(data))
+	})()
+	if err != nil {
+		return template.Must(dflt.Clone())
+	}
+	return custom
+}

internal/dis/component/server/templating/templating.go

@@ -1,4 +1,4 @@
-package templates
+package templating
 
 import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"

internal/dis/distillery.go

@@ -25,7 +25,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/home"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/legal"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/news"
-	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templates"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/server/templating"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/solr"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/sql"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/ssh2"
@@ -116,8 +116,8 @@ func (dis *Distillery) Info() *admin.Admin {
 func (dis *Distillery) Policy() *policy.Policy {
 	return export[*policy.Policy](dis)
 }
-func (dis *Distillery) Templating() *templates.Templating {
+func (dis *Distillery) Templating() *templating.Templating {
-	return export[*templates.Templating](dis)
+	return export[*templating.Templating](dis)
 }
 
 func (dis *Distillery) Purger() *purger.Purger {
@@ -190,7 +190,7 @@ func (dis *Distillery) allComponents() []initFunc {
 		auto[*news.News],
 
 		auto[*assets.Static],
-		auto[*templates.Templating],
+		auto[*templating.Templating],
 
 		// Cron
 		auto[*cron.Cron],

pkg/httpx/errors.go

@@ -49,6 +49,7 @@ func StatusInterceptor(contentType string, body func(code int, text string) ([]b
 
 	return ErrInterceptor{
 		Errors: map[error]Response{
+			ErrInternalServerError: makeResponse(http.StatusInternalServerError),
 			ErrBadRequest:          makeResponse(http.StatusBadRequest),
 			ErrNotFound:            makeResponse(http.StatusNotFound),
 			ErrForbidden:           makeResponse(http.StatusForbidden),
@@ -60,6 +61,7 @@ func StatusInterceptor(contentType string, body func(code int, text string) ([]b
 
 // Common errors accepted by all httpx handlers
 var (
+	ErrInternalServerError = errors.New("httpx: Internal Server Error")
 	ErrBadRequest          = errors.New("httpx: Bad Request")
 	ErrNotFound            = errors.New("httpx: Not Found")
 	ErrForbidden           = errors.New("httpx: Forbidden")

pkg/httpx/form.go

@@ -5,6 +5,8 @@ import (
 	"net/http"
 	"strings"
 
+	_ "embed"
+
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx/field"
 	"github.com/gorilla/csrf"
 )
@@ -173,3 +175,9 @@ func (form *Form[D]) renderSuccess(data D, values map[string]string, w http.Resp
 	}
 	form.renderForm(err, values, w, r)
 }
+
+//go:embed "form.html"
+var formBytes []byte
+
+// FormTeplate is a template to embed a form
+var FormTemplate = template.Must(template.New("form.html").Parse(string(formBytes)))

pkg/httpx/form.html

@@ -1,14 +1,8 @@
-{{ template "_base.html" . }}
-{{ define "title" }}{{ block "form/title" . }}Form{{ end }}{{ end }}
-
-{{ define "content" }}
 <div class="pure-u-1">
     {{ block "form/extra" . }}<!-- no extra -->{{ end }}
 
     <form class="pure-form pure-form-aligned" method="POST">
         <fieldset>
-            <legend>{{ template "form/title" . }}</legend>
-
             {{ block "form/message" . }}
                 {{ $E := .Error }}
                 {{ if not (eq $E "") }}
@@ -26,5 +20,3 @@
         </fieldset>
     </form>
 </div>
-
-{{ end }}