footer: Add a semi-flexible template system

internal/dis/component/auth/login.html

@@ -1,3 +1,20 @@
 {{ template "_form.html" . }}
 {{ define "form/title" }}Login Required{{ end }}
 {{ define "form/button" }}Login{{ end }}
+{{ define "form/inside" }}
+<div class="pure-form-group">
+    <p>
+        The site you are attempting to access requires you to login with your account.
+        Simply fill out the form below and click <em>Login</em>.
+    </p>
+    <p>
+        <small>
+            This functionality requires you to have cookies enabled.
+            A cookie to prevent fraudulent login attempts has already been set on your machine.
+            When clicking the <em>Login</em> button, a further cookie will be set on your computer to keep track of your login session.
+            If you do not wish to have futher cookie(s) set, do not click Login and do not attempt to access protected sites.
+            See also <a href="/legal/#cookies">Legal Notices</a>.
+        </small>
+    </p>
+</div>
+{{ end }}

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

@@ -79,7 +79,7 @@ func (panel *UserPanel) UserFormContext(ctx httpx.FormContext, r *http.Request)
 	user, err := panel.Dependencies.Auth.UserOf(r)
 
 	uctx := userFormContext{FormContext: ctx}
-	panel.Dependencies.Custom.Update(&uctx)
+	panel.Dependencies.Custom.Update(&uctx, r)
 	if err == nil {
 		uctx.User = &user.User
 	}

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

@@ -98,7 +98,7 @@ func (panel *UserPanel) routeTOTPEnroll(ctx context.Context) http.Handler {
 					FormContext: context,
 				},
 			}
-			panel.Dependencies.Custom.Update(&ctx.userFormContext)
+			panel.Dependencies.Custom.Update(&ctx.userFormContext, r)
 
 			if err == nil && user != nil {
 				ctx.userFormContext.User = &user.User

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

@@ -28,9 +28,9 @@ func (panel *UserPanel) routeUser(ctx context.Context) http.Handler {
 	userTemplate := panel.Dependencies.Custom.Template(userTemplate)
 	return &httpx.HTMLHandler[routeUserContext]{
 		Handler: func(r *http.Request) (ruc routeUserContext, err error) {
-			panel.Dependencies.Custom.Update(&ruc)
+			panel.Dependencies.Custom.Update(&ruc, r)
 			ruc.AuthUser, err = panel.Dependencies.Auth.UserOf(r)
-			return routeUserContext{}, err
+			return ruc, err
 		},
 		Template: userTemplate,
 	}

internal/dis/component/auth/session.go

@@ -125,7 +125,7 @@ func (auth *Auth) authLogin(ctx context.Context) http.Handler {
 			if context.Err != nil {
 				context.Err = errLoginFailed
 			}
-			httpx.WriteHTML(auth.Dependencies.Custom.NewForm(context), nil, loginTemplate, "", w, r)
+			httpx.WriteHTML(auth.Dependencies.Custom.NewForm(context, r), nil, loginTemplate, "", w, r)
 		},
 
 		Validate: func(r *http.Request, values map[string]string) (*AuthUser, error) {

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

@@ -28,7 +28,7 @@ type componentContext struct {
 }
 
 func (admin *Admin) components(r *http.Request) (cp componentContext, err error) {
-	admin.Dependencies.Custom.Update(&cp)
+	admin.Dependencies.Custom.Update(&cp, r)
 
 	cp.Analytics = *admin.Analytics
 	return
@@ -49,7 +49,7 @@ type ingredientsContext struct {
 }
 
 func (admin *Admin) ingredients(r *http.Request) (cp ingredientsContext, err error) {
-	admin.Dependencies.Custom.Update(&cp)
+	admin.Dependencies.Custom.Update(&cp, r)
 
 	// find the instance itself!
 	instance, err := admin.Dependencies.Instances.WissKI(r.Context(), mux.Vars(r)["slug"])

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

@@ -87,7 +87,7 @@ type indexContext struct {
 }
 
 func (admin *Admin) index(r *http.Request) (idx indexContext, err error) {
-	admin.Dependencies.Custom.Update(&idx)
+	admin.Dependencies.Custom.Update(&idx, r)
 	idx.Distillery, idx.Instances, err = admin.Status(r.Context(), true)
 	return
 }

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

@@ -2,7 +2,6 @@ package admin
 
 import (
 	_ "embed"
-	"html/template"
 	"net/http"
 
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/control/static"
@@ -25,13 +24,12 @@ var instanceTemplate = static.AssetsAdmin.MustParseShared(
 type instanceContext struct {
 	custom.BaseContext
 
-	CSRF     template.HTML
 	Instance models.Instance
 	Info     status.WissKI
 }
 
 func (admin *Admin) instance(r *http.Request) (is instanceContext, err error) {
-	admin.Dependencies.Custom.Update(&is)
+	admin.Dependencies.Custom.Update(&is, r)
 
 	is.CSRF = csrf.TemplateField(r)
 

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

@@ -3,7 +3,6 @@ package admin
 import (
 	"context"
 	"errors"
-	"html/template"
 	"net/http"
 
 	_ "embed"
@@ -27,12 +26,11 @@ type userContext struct {
 	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)
+	admin.Dependencies.Custom.Update(&uc, r)
 
 	uc.CSRF = csrf.TemplateField(r)
 	uc.Users, err = admin.Dependencies.Auth.Users(r.Context())

internal/dis/component/control/home/home.html

@@ -1,9 +1,6 @@
 {{ template "_base.html" . }}
 {{ define "title" }}WissKI Distillery{{ end }}
 
-{{ define "header/time" }}
-<!-- no header/time -->
-{{ end }}
 {{ define "header"}}
 <!-- no header -->
 {{ end }}

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

@@ -33,7 +33,7 @@ var homeTemplate = static.AssetsHome.MustParseShared("home.html", homeHTMLStr)
 
 func (home *Home) homeRender(ctx context.Context) ([]byte, error) {
 	var context homeContext
-	home.Dependencies.Custom.Update(&context)
+	home.Dependencies.Custom.Update(&context, nil)
 
 	// setup a couple of static things
 	context.Time = time.Now().UTC()
@@ -60,10 +60,10 @@ func (home *Home) homeRender(ctx context.Context) ([]byte, error) {
 
 	// render the template
 	var buffer bytes.Buffer
-	home.homeTemplate.Get(func() *template.Template {
+	err = home.homeTemplate.Get(func() *template.Template {
 		return home.Dependencies.Custom.Template(homeTemplate)
 	}).Execute(&buffer, context)
-	return buffer.Bytes(), nil
+	return buffer.Bytes(), err
 }
 
 type homeContext struct {

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

@@ -56,13 +56,13 @@ type legalContext struct {
 	AssetsDisclaimer string
 }
 
-func (legal *Legal) context(r *http.Request) (legalContext, error) {
-	return legalContext{
-		BaseContext:  legal.Dependencies.Custom.New(),
-		LegalNotices: cli.LegalNotices,
+func (legal *Legal) context(r *http.Request) (lc legalContext, err error) {
+	legal.Dependencies.Custom.Update(&lc, r)
 
-		CSRFCookie:       control.CSRFCookie,
-		SessionCookie:    control.SessionCookie,
-		AssetsDisclaimer: static.AssetsDisclaimer,
-	}, nil
+	lc.LegalNotices = cli.LegalNotices
+
+	lc.CSRFCookie = control.CSRFCookie
+	lc.SessionCookie = control.SessionCookie
+	lc.AssetsDisclaimer = static.AssetsDisclaimer
+	return
 }

internal/dis/component/control/legal/legal.html

@@ -1,9 +1,6 @@
 {{ template "_base.html" . }}
 {{ define "title" }}Legal{{ end }}
 
-{{ define "header/time" }}
-<!-- no header/time -->
-{{ end }}
 {{ define "header"}}
 <!-- no header -->
 {{ end }}

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

@@ -10,23 +10,23 @@ var AssetsDisclaimer string
 // AssetsHome contains assets for the 'Home' entrypoint.
 var AssetsHome = Assets{
 	Scripts: `<script type="module" src="/static/Home.38d394c2.js"></script><script src="/static/Home.38d394c2.js" nomodule="" defer></script><script type="module" src="/static/Home.38d394c2.js"></script><script src="/static/Home.38d394c2.js" nomodule="" defer></script>`,
-	Styles:  `<link rel="stylesheet" href="/static/Home.9f00501f.css"><link rel="stylesheet" href="/static/Home.2353e048.css">`,	
+	Styles:  `<link rel="stylesheet" href="/static/Home.4b303448.css"><link rel="stylesheet" href="/static/Home.2353e048.css">`,	
 }
 
 // AssetsUser contains assets for the 'User' entrypoint.
 var AssetsUser = Assets{
 	Scripts: `<script type="module" src="/static/Home.38d394c2.js"></script><script src="/static/Home.38d394c2.js" nomodule="" defer></script><script type="module" src="/static/User.4197014b.js"></script><script src="/static/User.30d54198.js" nomodule="" defer></script>`,
-	Styles:  `<link rel="stylesheet" href="/static/Home.9f00501f.css"><link rel="stylesheet" href="/static/User.38d394c2.css">`,	
+	Styles:  `<link rel="stylesheet" href="/static/Home.4b303448.css"><link rel="stylesheet" href="/static/User.38d394c2.css">`,	
 }
 
 // AssetsAdmin contains assets for the 'Admin' entrypoint.
 var AssetsAdmin = Assets{
 	Scripts: `<script nomodule="" defer src="/static/User.30d54198.js"></script><script type="module" src="/static/User.4197014b.js"></script><script type="module" src="/static/Home.38d394c2.js"></script><script src="/static/Home.38d394c2.js" nomodule="" defer></script><script type="module" src="/static/Admin.4ca3cb6f.js"></script><script src="/static/Admin.9750ba9c.js" nomodule="" defer></script>`,
-	Styles:  `<link rel="stylesheet" href="/static/Home.9f00501f.css"><link rel="stylesheet" href="/static/Admin.6d59e220.css"><link rel="stylesheet" href="/static/User.38d394c2.css"><link rel="stylesheet" href="/static/Admin.6d2ae968.css">`,	
+	Styles:  `<link rel="stylesheet" href="/static/Home.4b303448.css"><link rel="stylesheet" href="/static/Admin.6d59e220.css"><link rel="stylesheet" href="/static/User.38d394c2.css"><link rel="stylesheet" href="/static/Admin.6d2ae968.css">`,	
 }
 
 // AssetsLegal contains assets for the 'Legal' entrypoint.
 var AssetsLegal = Assets{
 	Scripts: `<script type="module" src="/static/Home.38d394c2.js"></script><script src="/static/Home.38d394c2.js" nomodule="" defer></script><script type="module" src="/static/Legal.38d394c2.js"></script><script src="/static/Legal.38d394c2.js" nomodule="" defer></script>`,
-	Styles:  `<link rel="stylesheet" href="/static/Home.9f00501f.css"><link rel="stylesheet" href="/static/Legal.d1531eba.css"><link rel="stylesheet" href="/static/Legal.20259812.css">`,	
+	Styles:  `<link rel="stylesheet" href="/static/Home.4b303448.css"><link rel="stylesheet" href="/static/Legal.d1531eba.css"><link rel="stylesheet" href="/static/Legal.20259812.css">`,	
 }

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

@@ -0,0 +1,90 @@
+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/gorilla/csrf"
+	"github.com/tkw1536/goprogram/lib/reflectx"
+)
+
+// baseContextName is the name of the [BaseContext] type
+var baseContextName = reflectx.TypeOf[BaseContext]().Name()
+
+// BaseContext represents a context shared by all the templates.
+//
+// This context should always be initialized using the [custom.Update], [custom.New] or [custom.NewForm] functions.
+// Other invocations might cause an error at runtime.
+type BaseContext struct {
+	inited bool // has this context been inited
+
+	GeneratedAt time.Time // time this page was generated at
+
+	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 + "BaseContext not initialized" + errorSuffix
+)
+
+// 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, r *http.Request) *BaseContext {
+	tc.inited = true
+
+	tc.GeneratedAt = time.Now().UTC()
+
+	// setup the CSRF field
+	tc.CSRF = csrfError
+	if r != nil {
+		tc.CSRF = csrf.TemplateField(r)
+	}
+
+	return tc
+}
+
+func (bc BaseContext) DoInitCheck() template.HTML {
+	if !bc.inited {
+		return initError
+	}
+	return ""
+}
+
+// NewForm is like New, but returns a new BaseFormContext
+func (custom *Custom) NewForm(context httpx.FormContext, r *http.Request) (ctx BaseFormContext) {
+	ctx.FormContext = context
+	ctx.use(custom.Base, r)
+	return
+}
+
+// RenderContext is exactly like NewForm, but returns any to be used as httpx.Form.RenderTemplateContext
+func (custom *Custom) RenderContext(ctx httpx.FormContext, r *http.Request) any {
+	return custom.NewForm(ctx, r)
+}
+
+// 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, r *http.Request) *BaseContext {
+	ctx := reflect.ValueOf(context).
+		Elem().FieldByName(baseContextName).Addr().
+		Interface().(*BaseContext)
+	ctx.use(custom.Base, r)
+	return ctx
+}
+
+// BaseFormContext combines BaseContext and FormContext
+type BaseFormContext struct {
+	BaseContext
+	httpx.FormContext
+}

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

@@ -5,4 +5,7 @@ import "github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 // Custom implements theme and page customization.
 type Custom struct {
 	component.Base
+	Dependencies struct {
+		// nothing yet
+	}
 }

internal/dis/component/control/static/custom/footer.html

@@ -0,0 +1,3 @@
+<p>
+    Generated <time format="{{ .GeneratedAt.Format "2006-01-02T15:04:05Z" }}">{{ .GeneratedAt.Format "2006-01-02T15:04:05Z07:00" }}</time> by <a href="https://github.com/FAU-CDI/wisski-distillery" target="_blank" rel="noopener noreferer">WissKI Distillery</a>. This site might use cookies for essential purposes, see also <a href="/legal/">Legal Notices</a>.
+</p>

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

@@ -1,20 +1,15 @@
 package custom
 
 import (
+	_ "embed"
 	"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>`))
+//go:embed "footer.html"
+var defaultTemplateStr string
+var defaultTemplate = template.Must(template.New("footer.html").Parse(defaultTemplateStr))
 
 // 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.
@@ -25,58 +20,3 @@ func (custom *Custom) Template(tpl *template.Template) *template.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/src/base/index.css

@@ -8,6 +8,20 @@ footer {
     margin: 2em;
 }
 
+footer {
+    font-size: small;
+    border-top: 1px solid black;
+    padding-top: 1em;
+}
+
+footer a {
+    color: blue !important;
+}
+
+time {
+    font-style: italic;
+}
+
 .padding {
     padding: 1em;
 }

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

@@ -9,14 +9,10 @@
 </head>
 
 <body>
+    {{ .BaseContext.DoInitCheck }}
     <header>
         <h1 id="top">{{ template "title" . }}</h1>
-        {{ block "header/time" . }}
-        {{ if .Time }}
-        <small>Generated at <code class="date">{{ .Time.Format "2006-01-02T15:04:05Z07:00" }}</code></small>
-        {{ end }}
-        {{ end }}
-        {{ block "header" . }}header{{ end }}
+        {{ block "header" . }}<!-- no header by default -->{{ end }}
     </header>
     <main>
         <div class="pure-g">
@@ -25,11 +21,8 @@
     </main>
 
     <footer>
-        {{ if .Time }}
-            Generated at <code>{{ .Time }}</code>
-        {{ end }}
-        {{ block "footer" . }}
-            <!-- no footer by default -->
+        {{ block "footer" .BaseContext }}
+            <!-- no footer -->
         {{ end }}
     </footer>
 

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

@@ -2,7 +2,6 @@
 {{ define "title" }}{{ block "form/title" . }}Form{{ end }}{{ end }}
 
 {{ define "header" }}<!-- no header -->{{ end }}
-{{ define "header/time" }}<!-- no time -->{{ end }}
 {{ define "content" }}
 <div class="pure-u-1">
     {{ block "form/extra" . }}<!-- no extra -->{{ end }}
@@ -24,7 +23,7 @@
 
             {{ block "form/inside" . }}<!-- no inside -->{{ end }}
             {{ .Form }}
-            <input type="submit" value="{{ block " form/button" .}}Submit{{ end }}" class="pure-button">
+            <input type="submit" value="{{ block "form/button" .}}Submit{{ end }}" class="pure-button">
         </fieldset>
     </form>
 </div>

pkg/httpx/html.go

@@ -3,14 +3,23 @@ package httpx
 import (
 	"html/template"
 	"net/http"
+
+	"github.com/rs/zerolog"
 )
 
 // WriteHTML writes a html response of type T to w.
 // If an error occured, writes an error response instead.
-func WriteHTML[T any](result T, err error, template *template.Template, templateName string, w http.ResponseWriter, r *http.Request) {
+func WriteHTML[T any](result T, err error, template *template.Template, templateName string, w http.ResponseWriter, r *http.Request) (e error) {
+	// log any error that occurs;
+	defer func() {
+		if e != nil {
+			zerolog.Ctx(r.Context()).Err(e).Str("path", r.URL.String()).Msg("error rendering template")
+		}
+	}()
+
 	// intercept any errors
 	if HTMLInterceptor.Intercept(w, r, err) {
-		return
+		return nil
 	}
 
 	// write out the response as html
@@ -23,9 +32,9 @@ func WriteHTML[T any](result T, err error, template *template.Template, template
 
 	// and return the template
 	if templateName != "" {
-		template.ExecuteTemplate(minifier, templateName, result)
+		return template.ExecuteTemplate(minifier, templateName, result)
 	} else {
-		template.Execute(minifier, result)
+		return template.Execute(minifier, result)
 	}
 }
 

pkg/httpx/html_minify.go

@@ -1,3 +1,5 @@
+//go:build nominify
+
 package httpx
 
 import (

pkg/httpx/html_minify_off.go

@@ -0,0 +1,27 @@
+//go:build !nominify
+
+package httpx
+
+import "io"
+
+// MinifyHTMLWriter wraps the given io.Writer to minify the given html instead.
+// The writer must be closed explicitly.
+//
+// Specific environments may chose to disable http minification, in which case MinifyHTMLWriter becomes the identity function.
+func MinifyHTMLWriter(dest io.Writer) io.WriteCloser {
+	return noop{Writer: dest}
+}
+
+type noop struct {
+	io.Writer
+}
+
+func (noop) Close() error {
+	return nil
+}
+
+// MinifyHTML minifies the html source.
+// If an error occurs, returns the unmodified source instead.
+func MinifyHTML(source []byte) []byte {
+	return source
+}