Implement image macro for rendering images

srv/default.nix

@@ -25,12 +25,10 @@
       # pow
       export MEDIOCRE_BLOG_POW_SECRET="${config.powSecret}"
 
-      # listening
+      # http
       export MEDIOCRE_BLOG_LISTEN_PROTO="${config.listenProto}"
       export MEDIOCRE_BLOG_LISTEN_ADDR="${config.listenAddr}"
-
-      # api
-      export MEDIOCRE_BLOG_API_AUTH_USERS='${builtins.toJSON config.httpAuthUsers}'
+      export MEDIOCRE_BLOG_HTTP_AUTH_USERS='${builtins.toJSON config.httpAuthUsers}'
     '';
 
     build = buildGoModule {

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

@@ -2,7 +2,6 @@ package main
 
 import (
 	"context"
-	"encoding/json"
 	"os"
 	"os/signal"
 	"syscall"
@@ -56,8 +55,6 @@ func main() {
 
 	pathPrefix := cfg.String("path-prefix", "", "Prefix which is optionally applied to all URL paths rendered by the blog")
 
-	httpAuthUsersStr := cfg.String("http-auth-users", "{}", "JSON object with usernames as values and password hashes (produced by the hash-password binary) as values. Denotes users which are able to edit server-side data")
-
 	// initialization
 	err := cfg.Init(ctx)
 
@@ -131,11 +128,6 @@ func main() {
 	postStore := post.NewStore(postSQLDB)
 	postAssetStore := post.NewAssetStore(postSQLDB)
 
-	var httpAuthUsers map[string]string
-	if err := json.Unmarshal([]byte(*httpAuthUsersStr), &httpAuthUsers); err != nil {
-		logger.Fatal(ctx, "unmarshaling -http-auth-users", err)
-	}
-
 	httpParams.Logger = logger.WithNamespace("http")
 	httpParams.PowManager = powMgr
 	httpParams.PathPrefix = *pathPrefix
@@ -144,7 +136,6 @@ func main() {
 	httpParams.MailingList = ml
 	httpParams.GlobalRoom = chatGlobalRoom
 	httpParams.UserIDCalculator = chatUserIDCalc
-	httpParams.AuthUsers = httpAuthUsers
 
 	logger.Info(ctx, "listening")
 	httpAPI, err := http.New(httpParams)

srv/src/http/api.go

@@ -4,6 +4,7 @@ package http
 import (
 	"context"
 	"embed"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"html/template"
@@ -57,6 +58,15 @@ type Params struct {
 func (p *Params) SetupCfg(cfg *cfg.Cfg) {
 	cfg.StringVar(&p.ListenProto, "listen-proto", "tcp", "Protocol to listen for HTTP requests with")
 	cfg.StringVar(&p.ListenAddr, "listen-addr", ":4000", "Address/path to listen for HTTP requests on")
+
+	httpAuthUsersStr := cfg.String("http-auth-users", "{}", "JSON object with usernames as values and password hashes (produced by the hash-password binary) as values. Denotes users which are able to edit server-side data")
+
+	cfg.OnInit(func(context.Context) error {
+		if err := json.Unmarshal([]byte(*httpAuthUsersStr), &p.AuthUsers); err != nil {
+			return fmt.Errorf("unmarshaling -http-auth-users: %w", err)
+		}
+		return nil
+	})
 }
 
 // Annotate implements mctx.Annotator interface.

srv/src/http/assets.go

@@ -17,6 +17,15 @@ import (
 	"golang.org/x/image/draw"
 )
 
+func isImgResizable(id string) bool {
+	switch strings.ToLower(filepath.Ext(id)) {
+	case ".jpg", ".jpeg", ".png":
+		return true
+	default:
+		return false
+	}
+}
+
 func resizeImage(out io.Writer, in io.Reader, maxWidth float64) error {
 
 	img, format, err := image.Decode(in)
@@ -123,8 +132,10 @@ func (a *api) getPostAssetHandler() http.Handler {
 			return
 		}
 
-		switch ext := strings.ToLower(strings.TrimPrefix(filepath.Ext(id), ".")); ext {
-		case "jpg", "jpeg", "png":
+		if !isImgResizable(id) {
+			apiutil.BadRequest(rw, r, fmt.Errorf("cannot resize file %q", id))
+			return
+		}
 
 		if err := resizeImage(rw, buf, float64(maxWidth)); err != nil {
 			apiutil.InternalServerError(
@@ -136,11 +147,6 @@ func (a *api) getPostAssetHandler() http.Handler {
 			)
 		}
 
-		default:
-			apiutil.BadRequest(rw, r, fmt.Errorf("cannot resize file with extension %q", ext))
-			return
-		}
-
 	})
 }
 

srv/src/http/posts.go

@@ -1,6 +1,7 @@
 package http
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"html/template"
@@ -23,13 +24,24 @@ type postTplPayload struct {
 }
 
 func (a *api) postToPostTplPayload(storedPost post.StoredPost) (postTplPayload, error) {
+
+	bodyTpl, err := a.parseTpl(storedPost.Body)
+	if err != nil {
+		return postTplPayload{}, fmt.Errorf("parsing post body as template: %w", err)
+	}
+
+	bodyBuf := new(bytes.Buffer)
+	if err := bodyTpl.Execute(bodyBuf, nil); err != nil {
+		return postTplPayload{}, fmt.Errorf("executing post body as template: %w", err)
+	}
+
 	parserExt := parser.CommonExtensions | parser.AutoHeadingIDs
 	parser := parser.NewWithExtensions(parserExt)
 
 	htmlFlags := html.CommonFlags | html.HrefTargetBlank
 	htmlRenderer := html.NewRenderer(html.RendererOptions{Flags: htmlFlags})
 
-	renderedBody := markdown.ToHTML([]byte(storedPost.Body), parser, htmlRenderer)
+	renderedBody := markdown.ToHTML(bodyBuf.Bytes(), parser, htmlRenderer)
 
 	tplPayload := postTplPayload{
 		StoredPost: storedPost,

srv/src/http/tpl.go

@@ -1,6 +1,7 @@
 package http
 
 import (
+	"bytes"
 	"embed"
 	"fmt"
 	"html/template"
@@ -27,7 +28,7 @@ func mustReadTplFile(fileName string) string {
 	return string(b)
 }
 
-func (a *api) mustParseTpl(name string) *template.Template {
+func (a *api) parseTpl(tplBody string) (*template.Template, error) {
 
 	blogURL := func(path string) string {
 
@@ -43,7 +44,9 @@ func (a *api) mustParseTpl(name string) *template.Template {
 		return path
 	}
 
-	tpl := template.New("").Funcs(template.FuncMap{
+	tpl := template.New("root")
+
+	tpl = tpl.Funcs(template.FuncMap{
 		"BlogURL": blogURL,
 		"StaticURL": func(path string) string {
 			path = filepath.Join("static", path)
@@ -62,9 +65,39 @@ func (a *api) mustParseTpl(name string) *template.Template {
 		},
 	})
 
-	tpl = template.Must(tpl.Parse(mustReadTplFile(name)))
+	tpl = template.Must(tpl.New("image.html").Parse(mustReadTplFile("image.html")))
 
-	return tpl
+	tpl = tpl.Funcs(template.FuncMap{
+		"Image": func(id string) (template.HTML, error) {
+
+			tplPayload := struct {
+				ID        string
+				Resizable bool
+			}{
+				ID:        id,
+				Resizable: isImgResizable(id),
+			}
+
+			buf := new(bytes.Buffer)
+			if err := tpl.ExecuteTemplate(buf, "image.html", tplPayload); err != nil {
+				return "", err
+			}
+
+			return template.HTML(buf.Bytes()), nil
+		},
+	})
+
+	var err error
+
+	if tpl, err = tpl.New("").Parse(tplBody); err != nil {
+		return nil, err
+	}
+
+	return tpl, nil
+}
+
+func (a *api) mustParseTpl(name string) *template.Template {
+	return template.Must(a.parseTpl(mustReadTplFile(name)))
 }
 
 func (a *api) mustParseBasedTpl(name string) *template.Template {

srv/src/http/tpl/image.html

@@ -0,0 +1,5 @@
+<div style="text-align: center;">
+  <a href="{{ AssetURL .ID }}" target="_blank">
+    <img src="{{ AssetURL .ID }}{{ if .Resizable }}?w=800{{ end }}" />
+  </a>
+</div>