forgejo/modules/markup/markdown/markdown.go
zeripath 2a03e96bce
Allow markdown files to read from the LFS (#5787)
This PR makes it possible for the markdown renderer to render images and media straight from the LFS.

Fix #5746

Signed-off-by: Andrew Thornton [art27@cantab.net](mailto:art27@cantab.net)
2019-02-12 15:09:43 +00:00

202 lines
6 KiB
Go

// Copyright 2014 The Gogs Authors. All rights reserved.
// Copyright 2018 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package markdown
import (
"bytes"
"strings"
"code.gitea.io/gitea/modules/markup"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/util"
"github.com/russross/blackfriday"
)
// Renderer is a extended version of underlying render object.
type Renderer struct {
blackfriday.Renderer
URLPrefix string
IsWiki bool
}
var byteMailto = []byte("mailto:")
// Link defines how formal links should be processed to produce corresponding HTML elements.
func (r *Renderer) Link(out *bytes.Buffer, link []byte, title []byte, content []byte) {
// special case: this is not a link, a hash link or a mailto:, so it's a
// relative URL
if len(link) > 0 && !markup.IsLink(link) &&
link[0] != '#' && !bytes.HasPrefix(link, byteMailto) {
lnk := string(link)
if r.IsWiki {
lnk = util.URLJoin("wiki", lnk)
}
mLink := util.URLJoin(r.URLPrefix, lnk)
link = []byte(mLink)
}
if len(content) > 10 && string(content[0:9]) == "<a href=\"" && bytes.Contains(content[9:], []byte("<img")) {
// Image with link case: markdown `[![]()]()`
// If the content is an image, then we change the original href around it
// which points to itself to a new address "link"
rightQuote := bytes.Index(content[9:], []byte("\""))
content = bytes.Replace(content, content[9:9+rightQuote], link, 1)
out.Write(content)
} else {
r.Renderer.Link(out, link, title, content)
}
}
// List renders markdown bullet or digit lists to HTML
func (r *Renderer) List(out *bytes.Buffer, text func() bool, flags int) {
marker := out.Len()
if out.Len() > 0 {
out.WriteByte('\n')
}
if flags&blackfriday.LIST_TYPE_DEFINITION != 0 {
out.WriteString("<dl>")
} else if flags&blackfriday.LIST_TYPE_ORDERED != 0 {
out.WriteString("<ol class='ui list'>")
} else {
out.WriteString("<ul class='ui list'>")
}
if !text() {
out.Truncate(marker)
return
}
if flags&blackfriday.LIST_TYPE_DEFINITION != 0 {
out.WriteString("</dl>\n")
} else if flags&blackfriday.LIST_TYPE_ORDERED != 0 {
out.WriteString("</ol>\n")
} else {
out.WriteString("</ul>\n")
}
}
// ListItem defines how list items should be processed to produce corresponding HTML elements.
func (r *Renderer) ListItem(out *bytes.Buffer, text []byte, flags int) {
// Detect procedures to draw checkboxes.
prefix := ""
if bytes.HasPrefix(text, []byte("<p>")) {
prefix = "<p>"
}
switch {
case bytes.HasPrefix(text, []byte(prefix+"[ ] ")):
text = append([]byte(`<span class="ui fitted disabled checkbox"><input type="checkbox" disabled="disabled" /><label /></span>`), text[3+len(prefix):]...)
if prefix != "" {
text = bytes.Replace(text, []byte(prefix), []byte{}, 1)
}
case bytes.HasPrefix(text, []byte(prefix+"[x] ")):
text = append([]byte(`<span class="ui checked fitted disabled checkbox"><input type="checkbox" checked="" disabled="disabled" /><label /></span>`), text[3+len(prefix):]...)
if prefix != "" {
text = bytes.Replace(text, []byte(prefix), []byte{}, 1)
}
}
r.Renderer.ListItem(out, text, flags)
}
// Image defines how images should be processed to produce corresponding HTML elements.
func (r *Renderer) Image(out *bytes.Buffer, link []byte, title []byte, alt []byte) {
prefix := r.URLPrefix
if r.IsWiki {
prefix = util.URLJoin(prefix, "wiki", "raw")
}
prefix = strings.Replace(prefix, "/src/", "/media/", 1)
if len(link) > 0 && !markup.IsLink(link) {
lnk := string(link)
lnk = util.URLJoin(prefix, lnk)
lnk = strings.Replace(lnk, " ", "+", -1)
link = []byte(lnk)
}
// Put a link around it pointing to itself by default
out.WriteString(`<a href="`)
out.Write(link)
out.WriteString(`">`)
r.Renderer.Image(out, link, title, alt)
out.WriteString("</a>")
}
const (
blackfridayExtensions = 0 |
blackfriday.EXTENSION_NO_INTRA_EMPHASIS |
blackfriday.EXTENSION_TABLES |
blackfriday.EXTENSION_FENCED_CODE |
blackfriday.EXTENSION_STRIKETHROUGH |
blackfriday.EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK
blackfridayHTMLFlags = 0 |
blackfriday.HTML_SKIP_STYLE |
blackfriday.HTML_OMIT_CONTENTS |
blackfriday.HTML_USE_SMARTYPANTS
)
// RenderRaw renders Markdown to HTML without handling special links.
func RenderRaw(body []byte, urlPrefix string, wikiMarkdown bool) []byte {
renderer := &Renderer{
Renderer: blackfriday.HtmlRenderer(blackfridayHTMLFlags, "", ""),
URLPrefix: urlPrefix,
IsWiki: wikiMarkdown,
}
exts := blackfridayExtensions
if setting.Markdown.EnableHardLineBreak {
exts |= blackfriday.EXTENSION_HARD_LINE_BREAK
}
body = blackfriday.Markdown(body, renderer, exts)
return body
}
var (
// MarkupName describes markup's name
MarkupName = "markdown"
)
func init() {
markup.RegisterParser(Parser{})
}
// Parser implements markup.Parser
type Parser struct {
}
// Name implements markup.Parser
func (Parser) Name() string {
return MarkupName
}
// Extensions implements markup.Parser
func (Parser) Extensions() []string {
return setting.Markdown.FileExtensions
}
// Render implements markup.Parser
func (Parser) Render(rawBytes []byte, urlPrefix string, metas map[string]string, isWiki bool) []byte {
return RenderRaw(rawBytes, urlPrefix, isWiki)
}
// Render renders Markdown to HTML with all specific handling stuff.
func Render(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
return markup.Render("a.md", rawBytes, urlPrefix, metas)
}
// RenderString renders Markdown to HTML with special links and returns string type.
func RenderString(raw, urlPrefix string, metas map[string]string) string {
return markup.RenderString("a.md", raw, urlPrefix, metas)
}
// RenderWiki renders markdown wiki page to HTML and return HTML string
func RenderWiki(rawBytes []byte, urlPrefix string, metas map[string]string) string {
return markup.RenderWiki("a.md", rawBytes, urlPrefix, metas)
}
// IsMarkdownFile reports whether name looks like a Markdown file
// based on its extension.
func IsMarkdownFile(name string) bool {
return markup.IsMarkupFile(name, MarkupName)
}