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authorDaniel Baumann <daniel@debian.org>2024-10-18 20:33:49 +0200
committerDaniel Baumann <daniel@debian.org>2024-10-18 20:33:49 +0200
commitdd136858f1ea40ad3c94191d647487fa4f31926c (patch)
tree58fec94a7b2a12510c9664b21793f1ed560c6518 /modules/markup/renderer.go
parentInitial commit. (diff)
downloadforgejo-debian.tar.xz
forgejo-debian.zip
Adding upstream version 9.0.0.upstream/9.0.0upstreamdebian
Signed-off-by: Daniel Baumann <daniel@debian.org>
Diffstat (limited to 'modules/markup/renderer.go')
-rw-r--r--modules/markup/renderer.go393
1 files changed, 393 insertions, 0 deletions
diff --git a/modules/markup/renderer.go b/modules/markup/renderer.go
new file mode 100644
index 0000000..2137302
--- /dev/null
+++ b/modules/markup/renderer.go
@@ -0,0 +1,393 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markup
+
+import (
+ "bytes"
+ "context"
+ "errors"
+ "fmt"
+ "io"
+ "net/url"
+ "path/filepath"
+ "strings"
+ "sync"
+
+ "code.gitea.io/gitea/modules/git"
+ "code.gitea.io/gitea/modules/setting"
+ "code.gitea.io/gitea/modules/util"
+
+ "github.com/yuin/goldmark/ast"
+)
+
+type RenderMetaMode string
+
+const (
+ RenderMetaAsDetails RenderMetaMode = "details" // default
+ RenderMetaAsNone RenderMetaMode = "none"
+ RenderMetaAsTable RenderMetaMode = "table"
+)
+
+type ProcessorHelper struct {
+ IsUsernameMentionable func(ctx context.Context, username string) bool
+ GetRepoFileBlob func(ctx context.Context, ownerName, repoName, commitSha, filePath string, language *string) (*git.Blob, error)
+
+ ElementDir string // the direction of the elements, eg: "ltr", "rtl", "auto", default to no direction attribute
+}
+
+var DefaultProcessorHelper ProcessorHelper
+
+// Init initialize regexps for markdown parsing
+func Init(ph *ProcessorHelper) {
+ if ph != nil {
+ DefaultProcessorHelper = *ph
+ }
+
+ NewSanitizer()
+ if len(setting.Markdown.CustomURLSchemes) > 0 {
+ CustomLinkURLSchemes(setting.Markdown.CustomURLSchemes)
+ }
+
+ // since setting maybe changed extensions, this will reload all renderer extensions mapping
+ extRenderers = make(map[string]Renderer)
+ for _, renderer := range renderers {
+ for _, ext := range renderer.Extensions() {
+ extRenderers[strings.ToLower(ext)] = renderer
+ }
+ }
+}
+
+// Header holds the data about a header.
+type Header struct {
+ Level int
+ Text string
+ ID string
+}
+
+// RenderContext represents a render context
+type RenderContext struct {
+ Ctx context.Context
+ RelativePath string // relative path from tree root of the branch
+ Type string
+ IsWiki bool
+ Links Links
+ Metas map[string]string
+ DefaultLink string
+ GitRepo *git.Repository
+ ShaExistCache map[string]bool
+ cancelFn func()
+ SidebarTocNode ast.Node
+ InStandalonePage bool // used by external render. the router "/org/repo/render/..." will output the rendered content in a standalone page
+}
+
+type Links struct {
+ AbsolutePrefix bool
+ Base string
+ BranchPath string
+ TreePath string
+}
+
+func (l *Links) Prefix() string {
+ if l.AbsolutePrefix {
+ return setting.AppURL
+ }
+ return setting.AppSubURL
+}
+
+func (l *Links) HasBranchInfo() bool {
+ return l.BranchPath != ""
+}
+
+func (l *Links) SrcLink() string {
+ return util.URLJoin(l.Base, "src", l.BranchPath, l.TreePath)
+}
+
+func (l *Links) MediaLink() string {
+ return util.URLJoin(l.Base, "media", l.BranchPath, l.TreePath)
+}
+
+func (l *Links) RawLink() string {
+ return util.URLJoin(l.Base, "raw", l.BranchPath, l.TreePath)
+}
+
+func (l *Links) WikiLink() string {
+ return util.URLJoin(l.Base, "wiki")
+}
+
+func (l *Links) WikiRawLink() string {
+ return util.URLJoin(l.Base, "wiki/raw")
+}
+
+func (l *Links) ResolveMediaLink(isWiki bool) string {
+ if isWiki {
+ return l.WikiRawLink()
+ } else if l.HasBranchInfo() {
+ return l.MediaLink()
+ }
+ return l.Base
+}
+
+// Cancel runs any cleanup functions that have been registered for this Ctx
+func (ctx *RenderContext) Cancel() {
+ if ctx == nil {
+ return
+ }
+ ctx.ShaExistCache = map[string]bool{}
+ if ctx.cancelFn == nil {
+ return
+ }
+ ctx.cancelFn()
+}
+
+// AddCancel adds the provided fn as a Cleanup for this Ctx
+func (ctx *RenderContext) AddCancel(fn func()) {
+ if ctx == nil {
+ return
+ }
+ oldCancelFn := ctx.cancelFn
+ if oldCancelFn == nil {
+ ctx.cancelFn = fn
+ return
+ }
+ ctx.cancelFn = func() {
+ defer oldCancelFn()
+ fn()
+ }
+}
+
+// Renderer defines an interface for rendering markup file to HTML
+type Renderer interface {
+ Name() string // markup format name
+ Extensions() []string
+ SanitizerRules() []setting.MarkupSanitizerRule
+ Render(ctx *RenderContext, input io.Reader, output io.Writer) error
+}
+
+// PostProcessRenderer defines an interface for renderers who need post process
+type PostProcessRenderer interface {
+ NeedPostProcess() bool
+}
+
+// PostProcessRenderer defines an interface for external renderers
+type ExternalRenderer interface {
+ // SanitizerDisabled disabled sanitize if return true
+ SanitizerDisabled() bool
+
+ // DisplayInIFrame represents whether render the content with an iframe
+ DisplayInIFrame() bool
+}
+
+// RendererContentDetector detects if the content can be rendered
+// by specified renderer
+type RendererContentDetector interface {
+ CanRender(filename string, input io.Reader) bool
+}
+
+var (
+ extRenderers = make(map[string]Renderer)
+ renderers = make(map[string]Renderer)
+)
+
+// RegisterRenderer registers a new markup file renderer
+func RegisterRenderer(renderer Renderer) {
+ renderers[renderer.Name()] = renderer
+ for _, ext := range renderer.Extensions() {
+ extRenderers[strings.ToLower(ext)] = renderer
+ }
+}
+
+// GetRendererByFileName get renderer by filename
+func GetRendererByFileName(filename string) Renderer {
+ extension := strings.ToLower(filepath.Ext(filename))
+ return extRenderers[extension]
+}
+
+// GetRendererByType returns a renderer according type
+func GetRendererByType(tp string) Renderer {
+ return renderers[tp]
+}
+
+// DetectRendererType detects the markup type of the content
+func DetectRendererType(filename string, input io.Reader) string {
+ buf, err := io.ReadAll(input)
+ if err != nil {
+ return ""
+ }
+ for _, renderer := range renderers {
+ if detector, ok := renderer.(RendererContentDetector); ok && detector.CanRender(filename, bytes.NewReader(buf)) {
+ return renderer.Name()
+ }
+ }
+ return ""
+}
+
+// Render renders markup file to HTML with all specific handling stuff.
+func Render(ctx *RenderContext, input io.Reader, output io.Writer) error {
+ if ctx.Type != "" {
+ return renderByType(ctx, input, output)
+ } else if ctx.RelativePath != "" {
+ return renderFile(ctx, input, output)
+ }
+ return errors.New("Render options both filename and type missing")
+}
+
+// RenderString renders Markup string to HTML with all specific handling stuff and return string
+func RenderString(ctx *RenderContext, content string) (string, error) {
+ var buf strings.Builder
+ if err := Render(ctx, strings.NewReader(content), &buf); err != nil {
+ return "", err
+ }
+ return buf.String(), nil
+}
+
+type nopCloser struct {
+ io.Writer
+}
+
+func (nopCloser) Close() error { return nil }
+
+func renderIFrame(ctx *RenderContext, output io.Writer) error {
+ // set height="0" ahead, otherwise the scrollHeight would be max(150, realHeight)
+ // at the moment, only "allow-scripts" is allowed for sandbox mode.
+ // "allow-same-origin" should never be used, it leads to XSS attack, and it makes the JS in iframe can access parent window's config and CSRF token
+ // TODO: when using dark theme, if the rendered content doesn't have proper style, the default text color is black, which is not easy to read
+ _, err := io.WriteString(output, fmt.Sprintf(`
+<iframe src="%s/%s/%s/render/%s/%s"
+name="giteaExternalRender"
+onload="this.height=giteaExternalRender.document.documentElement.scrollHeight"
+width="100%%" height="0" scrolling="no" frameborder="0" style="overflow: hidden"
+sandbox="allow-scripts"
+></iframe>`,
+ setting.AppSubURL,
+ url.PathEscape(ctx.Metas["user"]),
+ url.PathEscape(ctx.Metas["repo"]),
+ ctx.Metas["BranchNameSubURL"],
+ url.PathEscape(ctx.RelativePath),
+ ))
+ return err
+}
+
+func render(ctx *RenderContext, renderer Renderer, input io.Reader, output io.Writer) error {
+ var wg sync.WaitGroup
+ var err error
+ pr, pw := io.Pipe()
+ defer func() {
+ _ = pr.Close()
+ _ = pw.Close()
+ }()
+
+ var pr2 io.ReadCloser
+ var pw2 io.WriteCloser
+
+ var sanitizerDisabled bool
+ if r, ok := renderer.(ExternalRenderer); ok {
+ sanitizerDisabled = r.SanitizerDisabled()
+ }
+
+ if !sanitizerDisabled {
+ pr2, pw2 = io.Pipe()
+ defer func() {
+ _ = pr2.Close()
+ _ = pw2.Close()
+ }()
+
+ wg.Add(1)
+ go func() {
+ err = SanitizeReader(pr2, renderer.Name(), output)
+ _ = pr2.Close()
+ wg.Done()
+ }()
+ } else {
+ pw2 = nopCloser{output}
+ }
+
+ wg.Add(1)
+ go func() {
+ if r, ok := renderer.(PostProcessRenderer); ok && r.NeedPostProcess() {
+ err = PostProcess(ctx, pr, pw2)
+ } else {
+ _, err = io.Copy(pw2, pr)
+ }
+ _ = pr.Close()
+ _ = pw2.Close()
+ wg.Done()
+ }()
+
+ if err1 := renderer.Render(ctx, input, pw); err1 != nil {
+ return err1
+ }
+ _ = pw.Close()
+
+ wg.Wait()
+ return err
+}
+
+// ErrUnsupportedRenderType represents
+type ErrUnsupportedRenderType struct {
+ Type string
+}
+
+func (err ErrUnsupportedRenderType) Error() string {
+ return fmt.Sprintf("Unsupported render type: %s", err.Type)
+}
+
+func renderByType(ctx *RenderContext, input io.Reader, output io.Writer) error {
+ if renderer, ok := renderers[ctx.Type]; ok {
+ return render(ctx, renderer, input, output)
+ }
+ return ErrUnsupportedRenderType{ctx.Type}
+}
+
+// ErrUnsupportedRenderExtension represents the error when extension doesn't supported to render
+type ErrUnsupportedRenderExtension struct {
+ Extension string
+}
+
+func IsErrUnsupportedRenderExtension(err error) bool {
+ _, ok := err.(ErrUnsupportedRenderExtension)
+ return ok
+}
+
+func (err ErrUnsupportedRenderExtension) Error() string {
+ return fmt.Sprintf("Unsupported render extension: %s", err.Extension)
+}
+
+func renderFile(ctx *RenderContext, input io.Reader, output io.Writer) error {
+ extension := strings.ToLower(filepath.Ext(ctx.RelativePath))
+ if renderer, ok := extRenderers[extension]; ok {
+ if r, ok := renderer.(ExternalRenderer); ok && r.DisplayInIFrame() {
+ if !ctx.InStandalonePage {
+ // for an external render, it could only output its content in a standalone page
+ // otherwise, a <iframe> should be outputted to embed the external rendered page
+ return renderIFrame(ctx, output)
+ }
+ }
+ return render(ctx, renderer, input, output)
+ }
+ return ErrUnsupportedRenderExtension{extension}
+}
+
+// Type returns if markup format via the filename
+func Type(filename string) string {
+ if parser := GetRendererByFileName(filename); parser != nil {
+ return parser.Name()
+ }
+ return ""
+}
+
+// IsMarkupFile reports whether file is a markup type file
+func IsMarkupFile(name, markup string) bool {
+ if parser := GetRendererByFileName(name); parser != nil {
+ return parser.Name() == markup
+ }
+ return false
+}
+
+func PreviewableExtensions() []string {
+ extensions := make([]string, 0, len(extRenderers))
+ for extension := range extRenderers {
+ extensions = append(extensions, extension)
+ }
+ return extensions
+}