forked from
tangled.org/core
Monorepo for Tangled
appview: markdown: introduce post-processor step to transform image links
This adds a post-processor step to the markdown parser to parse raw
html images `<img>` and resolve their `src` attributes if needed
authored by
BrookJeynes
and committed by
Tangled
6dbaf7f9
9436c543
+99
-15
+10
-5
appview/pages/markup/camo.go
+10
-5
appview/pages/markup/camo.go
···
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return fmt.Sprintf("%s/%s/%s", baseURL, signature, hexURL)
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}
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-
func (rctx *RenderContext) camoImageLinkTransformer(img *ast.Image) {
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+
func (rctx *RenderContext) camoImageLinkTransformer(dst string) string {
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// don't camo on dev
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if rctx.IsDev {
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-
return
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return dst
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}
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dst := string(img.Destination)
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-
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if rctx.CamoUrl != "" && rctx.CamoSecret != "" {
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img.Destination = []byte(generateCamoURL(rctx.CamoUrl, rctx.CamoSecret, dst))
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return generateCamoURL(rctx.CamoUrl, rctx.CamoSecret, dst)
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}
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+
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return dst
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}
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+
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func (rctx *RenderContext) camoImageLinkAstTransformer(img *ast.Image) {
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dst := string(img.Destination)
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img.Destination = []byte(rctx.camoImageLinkTransformer(dst))
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}
+89
-10
appview/pages/markup/markdown.go
+89
-10
appview/pages/markup/markdown.go
···
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import (
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"bytes"
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"fmt"
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"io"
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"net/url"
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"path"
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"strings"
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"github.com/microcosm-cc/bluemonday"
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"github.com/yuin/goldmark"
···
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"github.com/yuin/goldmark/renderer/html"
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"github.com/yuin/goldmark/text"
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"github.com/yuin/goldmark/util"
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htmlparse "golang.org/x/net/html"
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"tangled.sh/tangled.sh/core/appview/pages/repoinfo"
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)
···
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if err := md.Convert([]byte(source), &buf); err != nil {
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return source
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}
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-
return buf.String()
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+
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var processed strings.Builder
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if err := postProcess(rctx, strings.NewReader(buf.String()), &processed); err != nil {
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return source
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}
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+
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return processed.String()
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}
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func postProcess(ctx *RenderContext, input io.Reader, output io.Writer) error {
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node, err := htmlparse.Parse(io.MultiReader(
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strings.NewReader("<html><body>"),
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input,
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strings.NewReader("</body></html>"),
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))
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if err != nil {
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return fmt.Errorf("failed to parse html: %w", err)
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}
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if node.Type == htmlparse.DocumentNode {
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node = node.FirstChild
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}
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visitNode(ctx, node)
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newNodes := make([]*htmlparse.Node, 0, 5)
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if node.Data == "html" {
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node = node.FirstChild
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for node != nil && node.Data != "body" {
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node = node.NextSibling
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}
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}
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if node != nil {
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if node.Data == "body" {
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child := node.FirstChild
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for child != nil {
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newNodes = append(newNodes, child)
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child = child.NextSibling
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}
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} else {
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newNodes = append(newNodes, node)
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}
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}
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for _, node := range newNodes {
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if err := htmlparse.Render(output, node); err != nil {
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return fmt.Errorf("failed to render processed html: %w", err)
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}
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}
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return nil
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}
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func visitNode(ctx *RenderContext, node *htmlparse.Node) {
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switch node.Type {
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case htmlparse.ElementNode:
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if node.Data == "img" {
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for i, attr := range node.Attr {
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if attr.Key != "src" {
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continue
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}
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attr.Val = ctx.imageFromKnotTransformer(attr.Val)
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attr.Val = ctx.camoImageLinkTransformer(attr.Val)
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node.Attr[i] = attr
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}
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}
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for n := node.FirstChild; n != nil; n = n.NextSibling {
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visitNode(ctx, n)
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}
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default:
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}
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}
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func (rctx *RenderContext) Sanitize(html string) string {
···
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case *ast.Link:
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a.rctx.relativeLinkTransformer(n)
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case *ast.Image:
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a.rctx.imageFromKnotTransformer(n)
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a.rctx.camoImageLinkTransformer(n)
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a.rctx.imageFromKnotAstTransformer(n)
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a.rctx.camoImageLinkAstTransformer(n)
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}
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case RendererTypeDefault:
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switch n := n.(type) {
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case *ast.Image:
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a.rctx.imageFromKnotTransformer(n)
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a.rctx.camoImageLinkTransformer(n)
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+
a.rctx.imageFromKnotAstTransformer(n)
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a.rctx.camoImageLinkAstTransformer(n)
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}
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}
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···
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link.Destination = []byte(newPath)
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}
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-
func (rctx *RenderContext) imageFromKnotTransformer(img *ast.Image) {
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-
dst := string(img.Destination)
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-
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+
func (rctx *RenderContext) imageFromKnotTransformer(dst string) string {
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if isAbsoluteUrl(dst) {
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-
return
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return dst
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}
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scheme := "https"
···
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actualPath),
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}
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newPath := parsedURL.String()
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-
img.Destination = []byte(newPath)
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+
return newPath
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+
}
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+
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+
func (rctx *RenderContext) imageFromKnotAstTransformer(img *ast.Image) {
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+
dst := string(img.Destination)
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img.Destination = []byte(rctx.imageFromKnotTransformer(dst))
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}
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// actualPath decides when to join the file path with the