61 lines
1.6 KiB
Go
61 lines
1.6 KiB
Go
// Package markdown provides markdown render functions.
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package markdown
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import (
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"regexp"
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"strings"
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"github.com/microcosm-cc/bluemonday"
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"github.com/shurcooL/github_flavored_markdown"
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)
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var (
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RegexpHTMLTag = regexp.MustCompile(`<(.|\n)+?>`)
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RegexpMarkdownLink = regexp.MustCompile(`\[([^\[\]]*)\]\((.*?)\)`)
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)
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// Render markdown from untrusted sources.
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func Render(input string) string {
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// Render Markdown to HTML.
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html := github_flavored_markdown.Markdown([]byte(input))
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// Sanitize the HTML from any nasties.
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p := bluemonday.UGCPolicy()
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safened := p.SanitizeBytes(html)
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return string(safened)
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}
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// Quotify a message putting it into a Markdown "> quotes" block.
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func Quotify(input string) string {
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var lines = []string{}
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for _, line := range strings.Split(input, "\n") {
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lines = append(lines, "> "+line)
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}
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return strings.Join(lines, "\n")
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}
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/*
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DeMarkify strips some Markdown syntax from plain text snippets.
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It is especially useful on Forum views that show plain text contents of posts, and especially
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for linked at-mentions of the form `[@username](/go/comment?id=1234)` so that those can be
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simplified down to just the `@username` text contents.
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This function will strip and simplify:
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- Markdown hyperlinks as spelled out above
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- Literal HTML tags such as <a href="">
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*/
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func DeMarkify(input string) string {
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// Strip all standard HTML tags.
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input = RegexpHTMLTag.ReplaceAllString(input, "")
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// Replace Markdown hyperlinks.
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matches := RegexpMarkdownLink.FindAllStringSubmatch(input, -1)
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for _, m := range matches {
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input = strings.ReplaceAll(input, m[0], m[1])
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}
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return input
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}
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