Function postProcessHTML

internal/markup/markup.go:245–317

postProcessHTML treats different types of HTML differently, and only renders special links for plain text blocks.

(rawHTML []byte, urlPrefix string, metas map[string]string)

// postProcessHTML treats different types of HTML differently,
// and only renders special links for plain text blocks.
func postProcessHTML(rawHTML []byte, urlPrefix string, metas map[string]string) []byte {
	startTags := make([]string, 0, 5)
	buf := bytes.NewBuffer(nil)
	tokenizer := html.NewTokenizer(bytes.NewReader(rawHTML))

outerLoop:
	for html.ErrorToken != tokenizer.Next() {
		token := tokenizer.Token()
		switch token.Type {
		case html.TextToken:
			buf.Write(RenderSpecialLink([]byte(token.String()), urlPrefix, metas))

		case html.StartTagToken:
			tagName := token.Data

			if tagName == "img" {
				wrapImgWithLink(urlPrefix, buf, token)
				continue outerLoop
			}

			buf.WriteString(token.String())
			// If this is an excluded tag, we skip processing all output until a close tag is encountered.
			if strings.EqualFold("a", tagName) || strings.EqualFold("code", tagName) || strings.EqualFold("pre", tagName) {
				stackNum := 1
				for html.ErrorToken != tokenizer.Next() {
					token = tokenizer.Token()

					// Copy the token to the output verbatim
					buf.WriteString(token.String())

					// Stack number doesn't increase for tags without end tags.
					if token.Type == html.StartTagToken && !com.IsSliceContainsStr(noEndTags, token.Data) {
						stackNum++
					}

					// If this is the close tag to the outer-most, we are done
					if token.Type == html.EndTagToken {
						stackNum--
						if stackNum <= 0 && strings.EqualFold(tagName, token.Data) {
							break
						}
					}
				}
				continue outerLoop
			}

			if !com.IsSliceContainsStr(noEndTags, tagName) {
				startTags = append(startTags, tagName)
			}

		case html.EndTagToken:
			if len(startTags) == 0 {
				buf.WriteString(token.String())
				break
			}

			buf.Write(leftAngleBracket)
			buf.WriteString(startTags[len(startTags)-1])