rewrite extender.New()

README.md

@@ -12,13 +12,12 @@ var source = []byte(`![alt](image.png "title")`)
 func Example() {
 	md := goldmark.New(
 		goldmark.WithExtensions(
-			images.NewExtender(func(src string) (string, map[string]string) {
-				return "loading.gif",
-					map[string]string{
-						"class":    "lazy",
-						"data-src": src,
-					}
-			}),
+			images.NewExtender(
+				"/loading.gif", // source
+				"data-src",    // target
+				map[string]string{
+					"class": "lazy", // arrtibute
+				}),
 		),
 	)
 	if err := md.Convert(source, os.Stdout); err != nil {
@@ -32,7 +31,7 @@ func Example() {
 
 ```html
 <p>
-<img src="loading.gif" alt="alt" title="title" class="lazy" data-src="image.png">
+<img src="/loading.gif" alt="alt" title="title" class="lazy" data-src="image.png">
 </p>
 ```
 

example_test.go

@@ -13,13 +13,12 @@ var source = []byte(`![alt](image.png "title")`)
 func Example() {
 	md := goldmark.New(
 		goldmark.WithExtensions(
-			images.NewExtender(func(src string) (string, map[string]string) {
-				return "loading.gif",
-					map[string]string{
-						"class":    "lazy",
-						"data-src": src,
-					}
-			}),
+			images.NewExtender(
+				"/loading.gif", // source
+				"data-src",     // target
+				map[string]string{
+					"class": "lazy", // arrtibute
+				}),
 		),
 	)
 	if err := md.Convert(source, os.Stdout); err != nil {
@@ -28,6 +27,6 @@ func Example() {
 
 	// Output:
 	// <p>
-	// <img src="loading.gif" alt="alt" title="title" class="lazy" data-src="image.png">
+	// <img src="/loading.gif" alt="alt" title="title" class="lazy" data-src="image.png">
 	// </p>
 }

extend.go

@@ -8,26 +8,27 @@ import (
 
 var extender *Extender
 
-type ReplaceFunc = func(src string) (string, map[string]string)
-
 type Extender struct {
-	ReplaceFunc
+	Source    string
+	Target    string
+	Attribute map[string]string
 }
 
 // New return initialized image render with source url replacing support.
-func NewExtender(opt ReplaceFunc) goldmark.Extender {
+func NewExtender(source, target string, attribute map[string]string) goldmark.Extender {
+
 	extender = &Extender{
-		ReplaceFunc: opt,
+		Source:    source,
+		Target:    target,
+		Attribute: attribute,
 	}
 	return extender
 }
 
 func (e *Extender) Extend(m goldmark.Markdown) {
-	if e.ReplaceFunc != nil {
-		m.Renderer().AddOptions(
-			renderer.WithNodeRenderers(
-				util.Prioritized(NewRenderer(), 500),
-			),
-		)
-	}
+	m.Renderer().AddOptions(
+		renderer.WithNodeRenderers(
+			util.Prioritized(NewRenderer(), 500),
+		),
+	)
 }

go.mod

@@ -2,4 +2,4 @@ module github.com/fundipper/goldmark-images
 
 go 1.18
 
-require github.com/yuin/goldmark v1.4.11
+require github.com/yuin/goldmark v1.4.11

render.go

@@ -29,27 +29,24 @@ func (r *Renderer) renderImage(w util.BufWriter, source []byte, node ast.Node, e
 
 	n := node.(*ast.Image)
 
-	if extender.ReplaceFunc != nil {
-		src, data := extender.ReplaceFunc(util.BytesToReadOnlyString(n.Destination))
-
-		n.Destination = util.StringToReadOnlyBytes(src)
-		for k, v := range data {
-			n.SetAttributeString(k, util.StringToReadOnlyBytes(v))
-		}
+	for k, v := range extender.Attribute {
+		n.SetAttributeString(k, util.StringToReadOnlyBytes(v))
 	}
+	n.SetAttributeString(extender.Target, n.Destination)
+	n.Destination = util.StringToReadOnlyBytes(extender.Source)
 
-	w.WriteString("<img src=\"")
+	w.WriteString(`<img src="`)
 	if r.Unsafe || !html.IsDangerousURL(n.Destination) {
 		w.Write(util.EscapeHTML(util.URLEscape(n.Destination, true)))
 	}
 	w.WriteString(`" alt="`)
 	w.Write(n.Text(source))
-	w.WriteByte('"')
+	w.WriteString(`"`)
 
 	if n.Title != nil {
 		w.WriteString(` title="`)
-		r.Writer.Write(w, n.Title)
-		w.WriteByte('"')
+		w.Write(n.Title)
+		w.WriteString(`"`)
 	}
 
 	if n.Attributes() != nil {
@@ -61,5 +58,6 @@ func (r *Renderer) renderImage(w util.BufWriter, source []byte, node ast.Node, e
 	} else {
 		w.WriteString(">")
 	}
+
 	return ast.WalkSkipChildren, nil
 }