custom: Add new footer template and context

internal/dis/component/control/admin/admin.go

@@ -6,6 +6,7 @@ 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/control/static/custom"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/exporter"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/exporter/logger"
 	"github.com/julienschmidt/httprouter"
@@ -26,6 +27,8 @@ type Admin struct {
 		SnapshotsLog *logger.Logger
 
 		Auth *auth.Auth
+
+		Custom *custom.Custom
 	}
 
 	Analytics *lazy.PoolAnalytics
@@ -64,13 +67,13 @@ func (admin *Admin) HandleRoute(ctx context.Context, route string) (handler http
 	// add a handler for the index page
 	router.Handler(http.MethodGet, route+"index", httpx.HTMLHandler[indexContext]{
 		Handler:  admin.index,
-		Template: indexTemplate,
+		Template: admin.Dependencies.Custom.Template(indexTemplate),
 	})
 
 	// add a handler for the user page
 	router.Handler(http.MethodGet, route+"users", httpx.HTMLHandler[userContext]{
 		Handler:  admin.users,
-		Template: userTemplate,
+		Template: admin.Dependencies.Custom.Template(userTemplate),
 	})
 
 	// add a user create form
@@ -90,19 +93,19 @@ func (admin *Admin) HandleRoute(ctx context.Context, route string) (handler http
 	// add a handler for the component page
 	router.Handler(http.MethodGet, route+"components", httpx.HTMLHandler[componentContext]{
 		Handler:  admin.components,
-		Template: componentsTemplate,
+		Template: admin.Dependencies.Custom.Template(componentsTemplate),
 	})
 
 	// add a handler for the component page
 	router.Handler(http.MethodGet, route+"ingredients/:slug", httpx.HTMLHandler[ingredientsContext]{
 		Handler:  admin.ingredients,
-		Template: ingredientsTemplate,
+		Template: admin.Dependencies.Custom.Template(ingredientsTemplate),
 	})
 
 	// add a handler for the instance page
 	router.Handler(http.MethodGet, route+"instance/:slug", httpx.HTMLHandler[instanceContext]{
 		Handler:  admin.instance,
-		Template: instanceTemplate,
+		Template: admin.Dependencies.Custom.Template(instanceTemplate),
 	})
 
 	// add a router for the login page

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

@@ -2,11 +2,11 @@ package admin
 
 import (
 	"net/http"
-	"time"
 
 	_ "embed"
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static/custom"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/instances"
 	"github.com/FAU-CDI/wisski-distillery/internal/models"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
@@ -22,15 +22,15 @@ var componentsTemplate = static.AssetsAdmin.MustParseShared(
 )
 
 type componentContext struct {
-	Time time.Time
+	custom.BaseContext
 
 	Analytics lazy.PoolAnalytics
 }
 
 func (admin *Admin) components(r *http.Request) (cp componentContext, err error) {
-	cp.Analytics = *admin.Analytics
-	cp.Time = time.Now().UTC()
+	admin.Dependencies.Custom.Update(&cp)
 
+	cp.Analytics = *admin.Analytics
 	return
 }
 
@@ -42,14 +42,14 @@ var ingredientsTemplate = static.AssetsAdmin.MustParseShared(
 )
 
 type ingredientsContext struct {
-	Time time.Time
+	custom.BaseContext
 
 	Instance  models.Instance
 	Analytics *lazy.PoolAnalytics
 }
 
 func (admin *Admin) ingredients(r *http.Request) (cp ingredientsContext, err error) {
-	cp.Time = time.Now().UTC()
+	admin.Dependencies.Custom.Update(&cp)
 
 	// find the instance itself!
 	instance, err := admin.Dependencies.Instances.WissKI(r.Context(), mux.Vars(r)["slug"])

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

@@ -9,6 +9,7 @@ import (
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static/custom"
 	"github.com/FAU-CDI/wisski-distillery/internal/status"
 	"golang.org/x/sync/errgroup"
 )
@@ -79,11 +80,14 @@ func (admin *Admin) Status(ctx context.Context, QuickInformation bool) (target s
 }
 
 type indexContext struct {
+	custom.BaseContext
+
 	status.Distillery
 	Instances []status.WissKI
 }
 
 func (admin *Admin) index(r *http.Request) (idx indexContext, err error) {
+	admin.Dependencies.Custom.Update(&idx)
 	idx.Distillery, idx.Instances, err = admin.Status(r.Context(), true)
 	return
 }

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

@@ -4,9 +4,9 @@ import (
 	_ "embed"
 	"html/template"
 	"net/http"
-	"time"
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static/custom"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/instances"
 	"github.com/FAU-CDI/wisski-distillery/internal/models"
 	"github.com/FAU-CDI/wisski-distillery/internal/status"
@@ -23,7 +23,7 @@ var instanceTemplate = static.AssetsAdmin.MustParseShared(
 )
 
 type instanceContext struct {
-	Time time.Time
+	custom.BaseContext
 
 	CSRF     template.HTML
 	Instance models.Instance
@@ -31,6 +31,8 @@ type instanceContext struct {
 }
 
 func (admin *Admin) instance(r *http.Request) (is instanceContext, err error) {
+	admin.Dependencies.Custom.Update(&is)
+
 	is.CSRF = csrf.TemplateField(r)
 
 	// find the instance itself!
@@ -49,8 +51,5 @@ func (admin *Admin) instance(r *http.Request) (is instanceContext, err error) {
 		return is, err
 	}
 
-	// current time
-	is.Time = time.Now().UTC()
-
 	return
 }

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

@@ -5,12 +5,12 @@ import (
 	"errors"
 	"html/template"
 	"net/http"
-	"time"
 
 	_ "embed"
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/auth"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static/custom"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
 	"github.com/gorilla/csrf"
 	"github.com/rs/zerolog"
@@ -24,15 +24,17 @@ var userTemplate = static.AssetsAdmin.MustParseShared(
 )
 
 type userContext struct {
-	Time time.Time
+	custom.BaseContext
+	httpx.FormContext
 
 	CSRF  template.HTML
 	Users []*auth.AuthUser
 }
 
 func (admin *Admin) users(r *http.Request) (uc userContext, err error) {
+	admin.Dependencies.Custom.Update(&uc)
+
 	uc.CSRF = csrf.TemplateField(r)
-	uc.Time = time.Now()
 	uc.Users, err = admin.Dependencies.Auth.Users(r.Context())
 	return
 }
@@ -56,6 +58,8 @@ type createUserResult struct {
 }
 
 func (admin *Admin) createUser(ctx context.Context) http.Handler {
+	userCreateTemplate := admin.Dependencies.Custom.Template(userCreateTemplate)
+
 	return &httpx.Form[createUserResult]{
 		Fields: []httpx.Field{
 			{Name: "username", Type: httpx.TextField, Label: "Username"},
@@ -64,7 +68,8 @@ func (admin *Admin) createUser(ctx context.Context) http.Handler {
 		},
 		FieldTemplate: httpx.PureCSSFieldTemplate,
 
-		RenderTemplate: userCreateTemplate,
+		RenderTemplate:        userCreateTemplate,
+		RenderTemplateContext: admin.Dependencies.Custom.RenderContext,
 
 		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"] == "on"

internal/dis/component/control/home/home.go

@@ -3,9 +3,11 @@ package home
 import (
 	"context"
 	"fmt"
+	"html/template"
 	"net/http"
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static/custom"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/instances"
 	"github.com/FAU-CDI/wisski-distillery/pkg/lazy"
 )
@@ -14,11 +16,13 @@ type Home struct {
 	component.Base
 	Dependencies struct {
 		Instances *instances.Instances
+		Custom    *custom.Custom
 	}
 
 	redirect      lazy.Lazy[*Redirect]
 	instanceNames lazy.Lazy[map[string]struct{}]
 	homeBytes     lazy.Lazy[[]byte]
+	homeTemplate  lazy.Lazy[*template.Template]
 }
 
 var (

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

@@ -3,11 +3,13 @@ package home
 import (
 	"bytes"
 	"context"
+	"html/template"
 	"time"
 
 	_ "embed"
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static/custom"
 	"github.com/FAU-CDI/wisski-distillery/internal/status"
 	"golang.org/x/sync/errgroup"
 )
@@ -30,7 +32,8 @@ var homeHTMLStr string
 var homeTemplate = static.AssetsHome.MustParseShared("home.html", homeHTMLStr)
 
 func (home *Home) homeRender(ctx context.Context) ([]byte, error) {
-	var context HomeContext
+	var context homeContext
+	home.Dependencies.Custom.Update(&context)
 
 	// setup a couple of static things
 	context.Time = time.Now().UTC()
@@ -57,11 +60,15 @@ func (home *Home) homeRender(ctx context.Context) ([]byte, error) {
 
 	// render the template
 	var buffer bytes.Buffer
-	homeTemplate.Execute(&buffer, context)
+	home.homeTemplate.Get(func() *template.Template {
+		return home.Dependencies.Custom.Template(homeTemplate)
+	}).Execute(&buffer, context)
 	return buffer.Bytes(), nil
 }
 
-type HomeContext struct {
+type homeContext struct {
+	custom.BaseContext
+
 	Instances []status.WissKI
 
 	Time time.Time

internal/dis/component/control/legal/legal.go

@@ -8,6 +8,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control"
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static/custom"
 	"github.com/FAU-CDI/wisski-distillery/pkg/httpx"
 
 	_ "embed"
@@ -15,6 +16,10 @@ import (
 
 type Legal struct {
 	component.Base
+	Dependencies struct {
+		Static *static.Static
+		Custom *custom.Custom
+	}
 }
 
 var (
@@ -33,6 +38,8 @@ func (legal *Legal) Routes() component.Routes {
 }
 
 func (legal *Legal) HandleRoute(ctx context.Context, route string) (http.Handler, error) {
+	legalTemplate := legal.Dependencies.Custom.Template(legalTemplate)
+
 	return httpx.HTMLHandler[legalContext]{
 		Handler:  legal.context,
 		Template: legalTemplate,
@@ -40,6 +47,8 @@ func (legal *Legal) HandleRoute(ctx context.Context, route string) (http.Handler
 }
 
 type legalContext struct {
+	custom.BaseContext
+
 	LegalNotices string
 
 	CSRFCookie       string
@@ -49,6 +58,7 @@ type legalContext struct {
 
 func (legal *Legal) context(r *http.Request) (legalContext, error) {
 	return legalContext{
+		BaseContext:  legal.Dependencies.Custom.New(),
 		LegalNotices: cli.LegalNotices,
 
 		CSRFCookie:       control.CSRFCookie,

internal/dis/component/control/static/custom/custom.go

@@ -0,0 +1,8 @@
+package custom
+
+import "github.com/FAU-CDI/wisski-distillery/internal/dis/component"
+
+// Custom implements theme and page customization.
+type Custom struct {
+	component.Base
+}

internal/dis/component/control/static/custom/template.go

@@ -0,0 +1,82 @@
+package custom
+
+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/tkw1536/goprogram/lib/reflectx"
+)
+
+const footerName = "footer"
+
+// defaultTemplate is the default footer template
+var defaultTemplate = template.Must(template.New("footer.html").Parse(`<p>Powered By WissKI Distillery</p>`))
+
+// 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 (custom *Custom) Template(tpl *template.Template) *template.Template {
+	tree := defaultTemplate.Tree.Copy()
+
+	clone := template.Must(tpl.Clone())                 // create a clone of the template
+	template.Must(clone.AddParseTree(footerName, tree)) // add the parse tree to it
+	return clone                                        // and return the tree
+}
+
+// NewContext returns a new BaseContext
+func (custom *Custom) New() (ctx BaseContext) {
+	ctx.Use(custom.Base)
+	return
+}
+
+// NewForm is like New, but returns a new BaseFormContext
+func (custom *Custom) NewForm(context httpx.FormContext) (ctx BaseFormContext) {
+	ctx.FormContext = context
+	ctx.Use(custom.Base)
+	return
+}
+
+// RenderContext can be used as httpx.Form.RenderTemplateContext.
+// It returns a new [BaseFormContext].
+func (custom *Custom) RenderContext(ctx httpx.FormContext, r *http.Request) any {
+	return BaseFormContext{
+		FormContext: ctx,
+		BaseContext: custom.New(),
+	}
+}
+
+// Update updates an embedded BaseContext field in context.
+//
+// Assumes that context is a pointer to a struct type.
+// If this is not the case, might call panic().
+func (custom *Custom) Update(context any) *BaseContext {
+	ctx := reflect.ValueOf(context).
+		Elem().FieldByName(contextName).Addr().
+		Interface().(*BaseContext)
+	ctx.Use(custom.Base)
+	return ctx
+}
+
+// contextName is the name of the [BaseContext] field.
+var contextName = reflectx.TypeOf[BaseContext]().Name()
+
+// BaseContext is a context struct shared by all contexts
+type BaseContext struct {
+	Time time.Time // time this page was generated at
+}
+
+// Use updates this context to use the values from the given base.
+// For convenience the passed context is also returned.
+func (tc *BaseContext) Use(base component.Base) *BaseContext {
+	tc.Time = time.Now().UTC()
+	return tc
+}
+
+// BaseFormContext combines BaseContext and FormContext
+type BaseFormContext struct {
+	BaseContext
+	httpx.FormContext
+}

internal/dis/component/control/static/templates/_base.html

@@ -2,7 +2,7 @@
 
 <head>
     <meta name="viewport" content="width=device-width, initial-scale=1">
-    <meta charset="utf-8"> 
+    <meta charset="utf-8">
 
     <title>{{ block "block" . }}WissKI Distillery{{ end }}</title>
     {{ block "styles" . }}styles{{ end }}
@@ -24,11 +24,15 @@
         </div>
     </main>
 
-    {{ if .Time }}
     <footer>
-        Generated at <code>{{ .Time }}</code>
+        {{ if .Time }}
+            Generated at <code>{{ .Time }}</code>
+        {{ end }}
+        {{ block "footer" . }}
+            <!-- no footer by default -->
+        {{ end }}
     </footer>
-    {{ end }}
-    
+
+
     {{ block "scripts" . }}scripts{{ end }}
 </body>