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- // Copyright 2014 The Gogs 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"
- "fmt"
- "io"
- "path"
- "path/filepath"
- "regexp"
- "strings"
- "github.com/Unknwon/com"
- "github.com/microcosm-cc/bluemonday"
- "github.com/russross/blackfriday"
- "golang.org/x/net/html"
- "github.com/gogits/gogs/modules/base"
- "github.com/gogits/gogs/modules/setting"
- )
- const (
- ISSUE_NAME_STYLE_NUMERIC = "numeric"
- ISSUE_NAME_STYLE_ALPHANUMERIC = "alphanumeric"
- )
- var Sanitizer = bluemonday.UGCPolicy()
- // BuildSanitizer initializes sanitizer with allowed attributes based on settings.
- // This function should only be called once during entire application lifecycle.
- func BuildSanitizer() {
- // Normal markdown-stuff
- Sanitizer.AllowAttrs("class").Matching(regexp.MustCompile(`[\p{L}\p{N}\s\-_',:\[\]!\./\\\(\)&]*`)).OnElements("code")
- // Checkboxes
- Sanitizer.AllowAttrs("type").Matching(regexp.MustCompile(`^checkbox$`)).OnElements("input")
- Sanitizer.AllowAttrs("checked", "disabled").OnElements("input")
- // Custom URL-Schemes
- Sanitizer.AllowURLSchemes(setting.Markdown.CustomURLSchemes...)
- }
- var validLinksPattern = regexp.MustCompile(`^[a-z][\w-]+://`)
- // isLink reports whether link fits valid format.
- func isLink(link []byte) bool {
- return validLinksPattern.Match(link)
- }
- // IsMarkdownFile reports whether name looks like a Markdown file
- // based on its extension.
- func IsMarkdownFile(name string) bool {
- name = strings.ToLower(name)
- switch filepath.Ext(name) {
- case ".md", ".markdown", ".mdown", ".mkd":
- return true
- }
- return false
- }
- // IsReadmeFile reports whether name looks like a README file
- // based on its extension.
- func IsReadmeFile(name string) bool {
- name = strings.ToLower(name)
- if len(name) < 6 {
- return false
- } else if len(name) == 6 {
- return name == "readme"
- }
- return name[:7] == "readme."
- }
- var (
- // MentionPattern matches string that mentions someone, e.g. @Unknwon
- MentionPattern = regexp.MustCompile(`(\s|^)@[0-9a-zA-Z-_\.]+`)
- // CommitPattern matches link to certain commit with or without trailing hash,
- // e.g. https://try.gogs.io/gogs/gogs/commit/d8a994ef243349f321568f9e36d5c3f444b99cae#diff-2
- CommitPattern = regexp.MustCompile(`(\s|^)https?.*commit/[0-9a-zA-Z]+(#+[0-9a-zA-Z-]*)?`)
- // IssueFullPattern matches link to an issue with or without trailing hash,
- // e.g. https://try.gogs.io/gogs/gogs/issues/4#issue-685
- IssueFullPattern = regexp.MustCompile(`(\s|^)https?.*issues/[0-9]+(#+[0-9a-zA-Z-]*)?`)
- // IssueNumericPattern matches string that references to a numeric issue, e.g. #1287
- IssueNumericPattern = regexp.MustCompile(`( |^|\()#[0-9]+\b`)
- // IssueAlphanumericPattern matches string that references to an alphanumeric issue, e.g. ABC-1234
- IssueAlphanumericPattern = regexp.MustCompile(`( |^|\()[A-Z]{1,10}-[1-9][0-9]*\b`)
- // Sha1CurrentPattern matches string that represents a commit SHA, e.g. d8a994ef243349f321568f9e36d5c3f444b99cae
- Sha1CurrentPattern = regexp.MustCompile(`\b[0-9a-f]{40}\b`)
- )
- // FindAllMentions matches mention patterns in given content
- // and returns a list of found user names without @ prefix.
- func FindAllMentions(content string) []string {
- mentions := MentionPattern.FindAllString(content, -1)
- for i := range mentions {
- mentions[i] = strings.TrimSpace(mentions[i])[1:] // Strip @ character
- }
- return mentions
- }
- // Renderer is a extended version of underlying render object.
- type Renderer struct {
- blackfriday.Renderer
- urlPrefix string
- }
- // 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) {
- if len(link) > 0 && !isLink(link) {
- if link[0] != '#' {
- link = []byte(path.Join(r.urlPrefix, string(link)))
- }
- }
- r.Renderer.Link(out, link, title, content)
- }
- // AutoLink defines how auto-detected links should be processed to produce corresponding HTML elements.
- // Reference for kind: https://github.com/russross/blackfriday/blob/master/markdown.go#L69-L76
- func (r *Renderer) AutoLink(out *bytes.Buffer, link []byte, kind int) {
- if kind != blackfriday.LINK_TYPE_NORMAL {
- r.Renderer.AutoLink(out, link, kind)
- return
- }
- // Since this method could only possibly serve one link at a time,
- // we do not need to find all.
- if bytes.HasPrefix(link, []byte(setting.AppUrl)) {
- m := CommitPattern.Find(link)
- if m != nil {
- m = bytes.TrimSpace(m)
- i := strings.Index(string(m), "commit/")
- j := strings.Index(string(m), "#")
- if j == -1 {
- j = len(m)
- }
- out.WriteString(fmt.Sprintf(` <code><a href="%s">%s</a></code>`, m, base.ShortSha(string(m[i+7:j]))))
- return
- }
- m = IssueFullPattern.Find(link)
- if m != nil {
- m = bytes.TrimSpace(m)
- i := strings.Index(string(m), "issues/")
- j := strings.Index(string(m), "#")
- if j == -1 {
- j = len(m)
- }
- out.WriteString(fmt.Sprintf(`<a href="%s">#%s</a>`, m, base.ShortSha(string(m[i+7:j]))))
- return
- }
- }
- r.Renderer.AutoLink(out, link, kind)
- }
- // ListItem defines how list items should be processed to produce corresponding HTML elements.
- func (options *Renderer) ListItem(out *bytes.Buffer, text []byte, flags int) {
- // Detect procedures to draw checkboxes.
- switch {
- case bytes.HasPrefix(text, []byte("[ ] ")):
- text = append([]byte(`<input type="checkbox" disabled="" />`), text[3:]...)
- case bytes.HasPrefix(text, []byte("[x] ")):
- text = append([]byte(`<input type="checkbox" disabled="" checked="" />`), text[3:]...)
- }
- options.Renderer.ListItem(out, text, flags)
- }
- // Note: this section is for purpose of increase performance and
- // reduce memory allocation at runtime since they are constant literals.
- var (
- svgSuffix = []byte(".svg")
- svgSuffixWithMark = []byte(".svg?")
- spaceBytes = []byte(" ")
- spaceEncodedBytes = []byte("%20")
- space = " "
- spaceEncoded = "%20"
- )
- // 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 := strings.Replace(r.urlPrefix, "/src/", "/raw/", 1)
- if len(link) > 0 {
- if isLink(link) {
- // External link with .svg suffix usually means CI status.
- // TODO: define a keyword to allow non-svg images render as external link.
- if bytes.HasSuffix(link, svgSuffix) || bytes.Contains(link, svgSuffixWithMark) {
- r.Renderer.Image(out, link, title, alt)
- return
- }
- } else {
- if link[0] != '/' {
- prefix += "/"
- }
- link = bytes.Replace([]byte((prefix + string(link))), spaceBytes, spaceEncodedBytes, -1)
- fmt.Println(333, string(link))
- }
- }
- out.WriteString(`<a href="`)
- out.Write(link)
- out.WriteString(`">`)
- r.Renderer.Image(out, link, title, alt)
- out.WriteString("</a>")
- }
- // cutoutVerbosePrefix cutouts URL prefix including sub-path to
- // return a clean unified string of request URL path.
- func cutoutVerbosePrefix(prefix string) string {
- if len(prefix) == 0 || prefix[0] != '/' {
- return prefix
- }
- count := 0
- for i := 0; i < len(prefix); i++ {
- if prefix[i] == '/' {
- count++
- }
- if count >= 3+setting.AppSubUrlDepth {
- return prefix[:i]
- }
- }
- return prefix
- }
- // RenderIssueIndexPattern renders issue indexes to corresponding links.
- func RenderIssueIndexPattern(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
- urlPrefix = cutoutVerbosePrefix(urlPrefix)
- pattern := IssueNumericPattern
- if metas["style"] == ISSUE_NAME_STYLE_ALPHANUMERIC {
- pattern = IssueAlphanumericPattern
- }
- ms := pattern.FindAll(rawBytes, -1)
- for _, m := range ms {
- if m[0] == ' ' || m[0] == '(' {
- m = m[1:] // ignore leading space or opening parentheses
- }
- var link string
- if metas == nil {
- link = fmt.Sprintf(`<a href="%s/issues/%s">%s</a>`, urlPrefix, m[1:], m)
- } else {
- // Support for external issue tracker
- if metas["style"] == ISSUE_NAME_STYLE_ALPHANUMERIC {
- metas["index"] = string(m)
- } else {
- metas["index"] = string(m[1:])
- }
- link = fmt.Sprintf(`<a href="%s">%s</a>`, com.Expand(metas["format"], metas), m)
- }
- rawBytes = bytes.Replace(rawBytes, m, []byte(link), 1)
- }
- return rawBytes
- }
- // RenderSha1CurrentPattern renders SHA1 strings to corresponding links that assumes in the same repository.
- func RenderSha1CurrentPattern(rawBytes []byte, urlPrefix string) []byte {
- ms := Sha1CurrentPattern.FindAll(rawBytes, -1)
- for _, m := range ms {
- rawBytes = bytes.Replace(rawBytes, m, []byte(fmt.Sprintf(
- `<a href="%s/commit/%s"><code>%s</code></a>`, urlPrefix, m, base.ShortSha(string(m)))), -1)
- }
- return rawBytes
- }
- // RenderSpecialLink renders mentions, indexes and SHA1 strings to corresponding links.
- func RenderSpecialLink(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
- ms := MentionPattern.FindAll(rawBytes, -1)
- for _, m := range ms {
- m = bytes.TrimSpace(m)
- rawBytes = bytes.Replace(rawBytes, m,
- []byte(fmt.Sprintf(`<a href="%s/%s">%s</a>`, setting.AppSubUrl, m[1:], m)), -1)
- }
- rawBytes = RenderIssueIndexPattern(rawBytes, urlPrefix, metas)
- rawBytes = RenderSha1CurrentPattern(rawBytes, urlPrefix)
- return rawBytes
- }
- // RenderRaw renders Markdown to HTML without handling special links.
- func RenderRaw(body []byte, urlPrefix string) []byte {
- htmlFlags := 0
- htmlFlags |= blackfriday.HTML_SKIP_STYLE
- htmlFlags |= blackfriday.HTML_OMIT_CONTENTS
- renderer := &Renderer{
- Renderer: blackfriday.HtmlRenderer(htmlFlags, "", ""),
- urlPrefix: urlPrefix,
- }
- // set up the parser
- extensions := 0
- extensions |= blackfriday.EXTENSION_NO_INTRA_EMPHASIS
- extensions |= blackfriday.EXTENSION_TABLES
- extensions |= blackfriday.EXTENSION_FENCED_CODE
- extensions |= blackfriday.EXTENSION_AUTOLINK
- extensions |= blackfriday.EXTENSION_STRIKETHROUGH
- extensions |= blackfriday.EXTENSION_SPACE_HEADERS
- extensions |= blackfriday.EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK
- if setting.Markdown.EnableHardLineBreak {
- extensions |= blackfriday.EXTENSION_HARD_LINE_BREAK
- }
- body = blackfriday.Markdown(body, renderer, extensions)
- return body
- }
- var (
- leftAngleBracket = []byte("</")
- rightAngleBracket = []byte(">")
- )
- var noEndTags = []string{"img", "input", "br", "hr"}
- // PostProcess treats different types of HTML differently,
- // and only renders special links for plain text blocks.
- func PostProcess(rawHtml []byte, urlPrefix string, metas map[string]string) []byte {
- startTags := make([]string, 0, 5)
- var buf bytes.Buffer
- tokenizer := html.NewTokenizer(bytes.NewReader(rawHtml))
- OUTER_LOOP:
- 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:
- buf.WriteString(token.String())
- tagName := token.Data
- // 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())
- if token.Type == html.StartTagToken {
- 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 OUTER_LOOP
- }
- if !com.IsSliceContainsStr(noEndTags, token.Data) {
- startTags = append(startTags, token.Data)
- }
- case html.EndTagToken:
- if len(startTags) == 0 {
- buf.WriteString(token.String())
- break
- }
- buf.Write(leftAngleBracket)
- buf.WriteString(startTags[len(startTags)-1])
- buf.Write(rightAngleBracket)
- startTags = startTags[:len(startTags)-1]
- default:
- buf.WriteString(token.String())
- }
- }
- if io.EOF == tokenizer.Err() {
- return buf.Bytes()
- }
- // If we are not at the end of the input, then some other parsing error has occurred,
- // so return the input verbatim.
- return rawHtml
- }
- // Render renders Markdown to HTML with special links.
- func Render(rawBytes []byte, urlPrefix string, metas map[string]string) []byte {
- urlPrefix = strings.Replace(urlPrefix, space, spaceEncoded, -1)
- result := RenderRaw(rawBytes, urlPrefix)
- result = PostProcess(result, urlPrefix, metas)
- result = Sanitizer.SanitizeBytes(result)
- return result
- }
- // RenderString renders Markdown to HTML with special links and returns string type.
- func RenderString(raw, urlPrefix string, metas map[string]string) string {
- return string(Render([]byte(raw), urlPrefix, metas))
- }
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