Add BlogURL template function

srv/src/api/api.go

@@ -26,6 +26,10 @@ type Params struct {
 	Logger     *mlog.Logger
 	PowManager pow.Manager
 
+	// PathPrefix, if given, will be prefixed to all url paths which are
+	// rendered by the API's templating system.
+	PathPrefix string
+
 	PostStore      post.Store
 	PostAssetStore post.AssetStore
 

srv/src/api/render.go

@@ -20,7 +20,7 @@ import (
 //go:embed tpl
 var tplFS embed.FS
 
-func mustParseTpl(name string) *template.Template {
+func (a *api) mustParseTpl(name string) *template.Template {
 
 	mustRead := func(fileName string) string {
 		path := filepath.Join("tpl", fileName)
@@ -33,7 +33,15 @@ func mustParseTpl(name string) *template.Template {
 		return string(b)
 	}
 
-	tpl := template.Must(template.New("").Parse(mustRead(name)))
+	blogURL := func(path string) string {
+		return filepath.Join(a.params.PathPrefix, "/v2", path)
+	}
+
+	tpl := template.New("").Funcs(template.FuncMap{
+		"BlogURL": blogURL,
+	})
+
+	tpl = template.Must(tpl.Parse(mustRead(name)))
 	tpl = template.Must(tpl.New("base.html").Parse(mustRead("base.html")))
 
 	return tpl
@@ -41,7 +49,7 @@ func mustParseTpl(name string) *template.Template {
 
 func (a *api) renderIndexHandler() http.Handler {
 
-	tpl := mustParseTpl("index.html")
+	tpl := a.mustParseTpl("index.html")
 	const pageCount = 10
 
 	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
@@ -95,7 +103,7 @@ func (a *api) renderIndexHandler() http.Handler {
 
 func (a *api) renderPostHandler() http.Handler {
 
-	tpl := mustParseTpl("post.html")
+	tpl := a.mustParseTpl("post.html")
 
 	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
 

srv/src/api/tpl/base.html

@@ -18,7 +18,7 @@
         <div class="row">
           <div class="seven columns" style="margin-bottom: 3rem;">
             <h1 class="title">
-              <a href="/">Mediocre Blog</a>
+              <a href="{{ BlogURL "/" }}">Mediocre Blog</a>
             </h1>
             <div class="light social">
               <span>By Brian Picciano</span>
@@ -31,13 +31,14 @@
 
           <div class="five columns light">
             <span style="display:block; margin-bottom:0.5rem;">Get notified when new posts are published!</span>
-            <a href="/follow.html">
+            <a href="{{ BlogURL "follow.html" }}">
               <button class="button-primary">
                 <i class="far fa-envelope"></i>
                 Follow
               </button>
             </a>
-            <a href="/feed.xml">
+
+            <a href="{{ BlogURL "feed.xml" }}">
               <button class="button">
                 <i class="fas fa-rss"></i>
                 RSS

srv/src/cmd/mediocre-blog/main.go

@@ -53,6 +53,8 @@ func main() {
 	chatGlobalRoomMaxMsgs := cfg.Int("chat-global-room-max-messages", 1000, "Maximum number of messages the global chat room can retain")
 	chatUserIDCalcSecret := cfg.String("chat-user-id-calc-secret", "", "Secret to use when calculating user ids")
 
+	pathPrefix := cfg.String("path-prefix", "", "Prefix which is optionally applied to all URL paths rendered by the blog")
+
 	// initialization
 	err := cfg.Init(ctx)
 
@@ -70,6 +72,10 @@ func main() {
 		"chatGlobalRoomMaxMsgs", *chatGlobalRoomMaxMsgs,
 	)
 
+	if *pathPrefix != "" {
+		ctx = mctx.Annotate(ctx, "pathPrefix", *pathPrefix)
+	}
+
 	clock := clock.Realtime()
 
 	powStore := pow.NewMemoryStore(clock)
@@ -124,6 +130,7 @@ func main() {
 
 	apiParams.Logger = logger.WithNamespace("api")
 	apiParams.PowManager = powMgr
+	apiParams.PathPrefix = *pathPrefix
 	apiParams.PostStore = postStore
 	apiParams.PostAssetStore = postAssetStore
 	apiParams.MailingList = ml