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gitea/modules/markup/html_codepreview.go
wxiaoguang ca5c895efb
Render embedded code preview by permlink in markdown (#30234)
The permlink in markdown will be rendered as a code preview block, like GitHub

Co-authored-by: silverwind <me@silverwind.io>
2024-04-02 17:48:27 +00:00

93 lines
3.0 KiB
Go

// Copyright 2024 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package markup
import (
"html/template"
"net/url"
"regexp"
"strconv"
"strings"
"code.gitea.io/gitea/modules/httplib"
"code.gitea.io/gitea/modules/log"
"golang.org/x/net/html"
)
// codePreviewPattern matches "http://domain/.../{owner}/{repo}/src/commit/{commit}/{filepath}#L10-L20"
var codePreviewPattern = regexp.MustCompile(`https?://\S+/([^\s/]+)/([^\s/]+)/src/commit/([0-9a-f]{7,64})(/\S+)#(L\d+(-L\d+)?)`)
type RenderCodePreviewOptions struct {
FullURL string
OwnerName string
RepoName string
CommitID string
FilePath string
LineStart, LineStop int
}
func renderCodeBlock(ctx *RenderContext, node *html.Node) (urlPosStart, urlPosStop int, htm template.HTML, err error) {
m := codePreviewPattern.FindStringSubmatchIndex(node.Data)
if m == nil {
return 0, 0, "", nil
}
opts := RenderCodePreviewOptions{
FullURL: node.Data[m[0]:m[1]],
OwnerName: node.Data[m[2]:m[3]],
RepoName: node.Data[m[4]:m[5]],
CommitID: node.Data[m[6]:m[7]],
FilePath: node.Data[m[8]:m[9]],
}
if !httplib.IsCurrentGiteaSiteURL(opts.FullURL) {
return 0, 0, "", nil
}
u, err := url.Parse(opts.FilePath)
if err != nil {
return 0, 0, "", err
}
opts.FilePath = strings.TrimPrefix(u.Path, "/")
lineStartStr, lineStopStr, _ := strings.Cut(node.Data[m[10]:m[11]], "-")
lineStart, _ := strconv.Atoi(strings.TrimPrefix(lineStartStr, "L"))
lineStop, _ := strconv.Atoi(strings.TrimPrefix(lineStopStr, "L"))
opts.LineStart, opts.LineStop = lineStart, lineStop
h, err := DefaultProcessorHelper.RenderRepoFileCodePreview(ctx.Ctx, opts)
return m[0], m[1], h, err
}
func codePreviewPatternProcessor(ctx *RenderContext, node *html.Node) {
for node != nil {
if node.Type != html.TextNode {
node = node.NextSibling
continue
}
urlPosStart, urlPosEnd, h, err := renderCodeBlock(ctx, node)
if err != nil || h == "" {
if err != nil {
log.Error("Unable to render code preview: %v", err)
}
node = node.NextSibling
continue
}
next := node.NextSibling
textBefore := node.Data[:urlPosStart]
textAfter := node.Data[urlPosEnd:]
// "textBefore" could be empty if there is only a URL in the text node, then an empty node (p, or li) will be left here.
// However, the empty node can't be simply removed, because:
// 1. the following processors will still try to access it (need to double-check undefined behaviors)
// 2. the new node is inserted as "<p>{TextBefore}<div NewNode/>{TextAfter}</p>" (the parent could also be "li")
// then it is resolved as: "<p>{TextBefore}</p><div NewNode/><p>{TextAfter}</p>",
// so unless it could correctly replace the parent "p/li" node, it is very difficult to eliminate the "TextBefore" empty node.
node.Data = textBefore
node.Parent.InsertBefore(&html.Node{Type: html.RawNode, Data: string(h)}, next)
if textAfter != "" {
node.Parent.InsertBefore(&html.Node{Type: html.TextNode, Data: textAfter}, next)
}
node = next
}
}