1 files changed, 208 insertions, 0 deletions
diff --git a/markup/goldmark/render_link.go b/markup/goldmark/render_link.go
new file mode 100644
index 000000000..17ba5bada
--- /dev/null
+++ b/markup/goldmark/render_link.go
@@ -0,0 +1,208 @@
+// Copyright 2019 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package goldmark
+
+import (
+	"github.com/gohugoio/hugo/markup/converter/hooks"
+
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/renderer"
+	"github.com/yuin/goldmark/renderer/html"
+	"github.com/yuin/goldmark/util"
+)
+
+var _ renderer.SetOptioner = (*linkRenderer)(nil)
+
+func newLinkRenderer() renderer.NodeRenderer {
+	r := &linkRenderer{
+		Config: html.Config{
+			Writer: html.DefaultWriter,
+		},
+	}
+	return r
+}
+
+func newLinks() goldmark.Extender {
+	return &links{}
+}
+
+type linkContext struct {
+	page        interface{}
+	destination string
+	title       string
+	text        string
+}
+
+func (ctx linkContext) Destination() string {
+	return ctx.destination
+}
+
+func (ctx linkContext) Resolved() bool {
+	return false
+}
+
+func (ctx linkContext) Page() interface{} {
+	return ctx.page
+}
+
+func (ctx linkContext) Text() string {
+	return ctx.text
+}
+
+func (ctx linkContext) Title() string {
+	return ctx.title
+}
+
+type linkRenderer struct {
+	html.Config
+}
+
+func (r *linkRenderer) SetOption(name renderer.OptionName, value interface{}) {
+	r.Config.SetOption(name, value)
+}
+
+// RegisterFuncs implements NodeRenderer.RegisterFuncs.
+func (r *linkRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
+	reg.Register(ast.KindLink, r.renderLink)
+	reg.Register(ast.KindImage, r.renderImage)
+}
+
+// Fall back to the default Goldmark render funcs. Method below borrowed from:
+// https://github.com/yuin/goldmark/blob/b611cd333a492416b56aa8d94b04a67bf0096ab2/renderer/html/html.go#L404
+func (r *linkRenderer) renderDefaultImage(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	if !entering {
+		return ast.WalkContinue, nil
+	}
+	n := node.(*ast.Image)
+	_, _ = 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('"')
+	if n.Title != nil {
+		_, _ = w.WriteString(` title="`)
+		r.Writer.Write(w, n.Title)
+		_ = w.WriteByte('"')
+	}
+	if r.XHTML {
+		_, _ = w.WriteString(" />")
+	} else {
+		_, _ = w.WriteString(">")
+	}
+	return ast.WalkSkipChildren, nil
+}
+
+// Fall back to the default Goldmark render funcs. Method below borrowed from:
+// https://github.com/yuin/goldmark/blob/b611cd333a492416b56aa8d94b04a67bf0096ab2/renderer/html/html.go#L404
+func (r *linkRenderer) renderDefaultLink(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	n := node.(*ast.Link)
+	if entering {
+		_, _ = w.WriteString("<a href=\"")
+		if r.Unsafe || !html.IsDangerousURL(n.Destination) {
+			_, _ = w.Write(util.EscapeHTML(util.URLEscape(n.Destination, true)))
+		}
+		_ = w.WriteByte('"')
+		if n.Title != nil {
+			_, _ = w.WriteString(` title="`)
+			r.Writer.Write(w, n.Title)
+			_ = w.WriteByte('"')
+		}
+		_ = w.WriteByte('>')
+	} else {
+		_, _ = w.WriteString("</a>")
+	}
+	return ast.WalkContinue, nil
+}
+
+func (r *linkRenderer) renderImage(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	n := node.(*ast.Image)
+	var h *hooks.Render
+
+	ctx, ok := w.(renderContextData)
+	if ok {
+		h = ctx.RenderContext().RenderHooks
+		ok = h != nil && h.ImageRenderer != nil
+	}
+
+	if !ok {
+		return r.renderDefaultImage(w, source, node, entering)
+	}
+
+	if !entering {
+		return ast.WalkContinue, nil
+	}
+
+	err := h.ImageRenderer.Render(
+		w,
+		linkContext{
+			page:        ctx.DocumentContext().Document,
+			destination: string(n.Destination),
+			title:       string(n.Title),
+			text:        string(n.Text(source)),
+		},
+	)
+
+	ctx.AddIdentity(h.ImageRenderer.GetIdentity())
+
+	return ast.WalkSkipChildren, err
+
+}
+
+func (r *linkRenderer) renderLink(w util.BufWriter, source []byte, node ast.Node, entering bool) (ast.WalkStatus, error) {
+	n := node.(*ast.Link)
+	var h *hooks.Render
+
+	ctx, ok := w.(renderContextData)
+	if ok {
+		h = ctx.RenderContext().RenderHooks
+		ok = h != nil && h.LinkRenderer != nil
+	}
+
+	if !ok {
+		return r.renderDefaultLink(w, source, node, entering)
+	}
+
+	if !entering {
+		return ast.WalkContinue, nil
+	}
+
+	err := h.LinkRenderer.Render(
+		w,
+		linkContext{
+			page:        ctx.DocumentContext().Document,
+			destination: string(n.Destination),
+			title:       string(n.Title),
+			text:        string(n.Text(source)),
+		},
+	)
+
+	ctx.AddIdentity(h.LinkRenderer.GetIdentity())
+
+	// Do not render the inner text.
+	return ast.WalkSkipChildren, err
+
+}
+
+type links struct {
+}
+
+// Extend implements goldmark.Extender.
+func (e *links) Extend(m goldmark.Markdown) {
+	m.Renderer().AddOptions(renderer.WithNodeRenderers(
+		util.Prioritized(newLinkRenderer(), 100),
+	))
+}