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gitea/modules/markup/render.go
wxiaoguang c4e27cb27b
Refactor markup render system (#32589)
This PR mainly moves some code and introduces `RenderContext.WithXxx`
functions
2024-11-22 05:48:09 +00:00

326 lines
9.6 KiB
Go

// Copyright 2024 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package markup
import (
"context"
"fmt"
"io"
"net/url"
"strings"
"time"
"code.gitea.io/gitea/modules/git"
"code.gitea.io/gitea/modules/gitrepo"
"code.gitea.io/gitea/modules/markup/internal"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/util"
"github.com/yuin/goldmark/ast"
"golang.org/x/sync/errgroup"
)
type RenderMetaMode string
const (
RenderMetaAsDetails RenderMetaMode = "details" // default
RenderMetaAsNone RenderMetaMode = "none"
RenderMetaAsTable RenderMetaMode = "table"
)
var RenderBehaviorForTesting struct {
// Markdown line break rendering has 2 default behaviors:
// * Use hard: replace "\n" with "<br>" for comments, setting.Markdown.EnableHardLineBreakInComments=true
// * Keep soft: "\n" for non-comments (a.k.a. documents), setting.Markdown.EnableHardLineBreakInDocuments=false
// In history, there was a mess:
// * The behavior was controlled by `Metas["mode"] != "document",
// * However, many places render the content without setting "mode" in Metas, all these places used comment line break setting incorrectly
ForceHardLineBreak bool
// Gitea will emit some internal attributes for various purposes, these attributes don't affect rendering.
// But there are too many hard-coded test cases, to avoid changing all of them again and again, we can disable emitting these internal attributes.
DisableInternalAttributes bool
}
type RenderOptions struct {
// relative path from tree root of the branch
RelativePath string
// eg: "orgmode", "asciicast", "console"
// for file mode, it could be left as empty, and will be detected by file extension in RelativePath
MarkupType string
// special link references for rendering, especially when there is a branch/tree path
Links Links
// user&repo, format&style&regexp (for external issue pattern), teams&org (for mention)
// BranchNameSubURL (for iframe&asciicast)
// markupAllowShortIssuePattern, markupContentMode (wiki)
// markdownLineBreakStyle (comment, document)
Metas map[string]string
// used by external render. the router "/org/repo/render/..." will output the rendered content in a standalone page
InStandalonePage bool
}
type RenderHelper struct {
gitRepo *git.Repository
repoFacade gitrepo.Repository
shaExistCache map[string]bool
cancelFn func()
}
// RenderContext represents a render context
type RenderContext struct {
ctx context.Context
SidebarTocNode ast.Node
RenderHelper RenderHelper
RenderOptions RenderOptions
RenderInternal internal.RenderInternal
}
func (ctx *RenderContext) Deadline() (deadline time.Time, ok bool) {
return ctx.ctx.Deadline()
}
func (ctx *RenderContext) Done() <-chan struct{} {
return ctx.ctx.Done()
}
func (ctx *RenderContext) Err() error {
return ctx.ctx.Err()
}
func (ctx *RenderContext) Value(key any) any {
return ctx.ctx.Value(key)
}
var _ context.Context = (*RenderContext)(nil)
func NewRenderContext(ctx context.Context) *RenderContext {
return &RenderContext{ctx: ctx}
}
func (ctx *RenderContext) WithMarkupType(typ string) *RenderContext {
ctx.RenderOptions.MarkupType = typ
return ctx
}
func (ctx *RenderContext) WithRelativePath(path string) *RenderContext {
ctx.RenderOptions.RelativePath = path
return ctx
}
func (ctx *RenderContext) WithLinks(links Links) *RenderContext {
ctx.RenderOptions.Links = links
return ctx
}
func (ctx *RenderContext) WithMetas(metas map[string]string) *RenderContext {
ctx.RenderOptions.Metas = metas
return ctx
}
func (ctx *RenderContext) WithInStandalonePage(v bool) *RenderContext {
ctx.RenderOptions.InStandalonePage = v
return ctx
}
func (ctx *RenderContext) WithGitRepo(r *git.Repository) *RenderContext {
ctx.RenderHelper.gitRepo = r
return ctx
}
func (ctx *RenderContext) WithRepoFacade(r gitrepo.Repository) *RenderContext {
ctx.RenderHelper.repoFacade = r
return ctx
}
// Cancel runs any cleanup functions that have been registered for this Ctx
func (ctx *RenderContext) Cancel() {
if ctx == nil {
return
}
ctx.RenderHelper.shaExistCache = map[string]bool{}
if ctx.RenderHelper.cancelFn == nil {
return
}
ctx.RenderHelper.cancelFn()
}
// AddCancel adds the provided fn as a Cleanup for this Ctx
func (ctx *RenderContext) AddCancel(fn func()) {
if ctx == nil {
return
}
oldCancelFn := ctx.RenderHelper.cancelFn
if oldCancelFn == nil {
ctx.RenderHelper.cancelFn = fn
return
}
ctx.RenderHelper.cancelFn = func() {
defer oldCancelFn()
fn()
}
}
func (ctx *RenderContext) IsMarkupContentWiki() bool {
return ctx.RenderOptions.Metas != nil && ctx.RenderOptions.Metas["markupContentMode"] == "wiki"
}
// Render renders markup file to HTML with all specific handling stuff.
func Render(ctx *RenderContext, input io.Reader, output io.Writer) error {
if ctx.RenderOptions.MarkupType == "" && ctx.RenderOptions.RelativePath != "" {
ctx.RenderOptions.MarkupType = DetectMarkupTypeByFileName(ctx.RenderOptions.RelativePath)
if ctx.RenderOptions.MarkupType == "" {
return util.NewInvalidArgumentErrorf("unsupported file to render: %q", ctx.RenderOptions.RelativePath)
}
}
renderer := renderers[ctx.RenderOptions.MarkupType]
if renderer == nil {
return util.NewInvalidArgumentErrorf("unsupported markup type: %q", ctx.RenderOptions.MarkupType)
}
if ctx.RenderOptions.RelativePath != "" {
if externalRender, ok := renderer.(ExternalRenderer); ok && externalRender.DisplayInIFrame() {
if !ctx.RenderOptions.InStandalonePage {
// for an external "DisplayInIFrame" 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)
}
// 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
}
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.RenderOptions.Metas["user"]),
url.PathEscape(ctx.RenderOptions.Metas["repo"]),
ctx.RenderOptions.Metas["BranchNameSubURL"],
url.PathEscape(ctx.RenderOptions.RelativePath),
))
return err
}
func pipes() (io.ReadCloser, io.WriteCloser, func()) {
pr, pw := io.Pipe()
return pr, pw, func() {
_ = pr.Close()
_ = pw.Close()
}
}
func render(ctx *RenderContext, renderer Renderer, input io.Reader, output io.Writer) error {
finalProcessor := ctx.RenderInternal.Init(output)
defer finalProcessor.Close()
// input -> (pw1=pr1) -> renderer -> (pw2=pr2) -> SanitizeReader -> finalProcessor -> output
// no sanitizer: input -> (pw1=pr1) -> renderer -> pw2(finalProcessor) -> output
pr1, pw1, close1 := pipes()
defer close1()
eg, _ := errgroup.WithContext(ctx)
var pw2 io.WriteCloser = util.NopCloser{Writer: finalProcessor}
if r, ok := renderer.(ExternalRenderer); !ok || !r.SanitizerDisabled() {
var pr2 io.ReadCloser
var close2 func()
pr2, pw2, close2 = pipes()
defer close2()
eg.Go(func() error {
defer pr2.Close()
return SanitizeReader(pr2, renderer.Name(), finalProcessor)
})
}
eg.Go(func() (err error) {
if r, ok := renderer.(PostProcessRenderer); ok && r.NeedPostProcess() {
err = PostProcess(ctx, pr1, pw2)
} else {
_, err = io.Copy(pw2, pr1)
}
_, _ = pr1.Close(), pw2.Close()
return err
})
if err := renderer.Render(ctx, input, pw1); err != nil {
return err
}
_ = pw1.Close()
return eg.Wait()
}
// Init initializes the render global variables
func Init(ph *ProcessorHelper) {
if ph != nil {
DefaultProcessorHelper = *ph
}
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
}
}
}
func ComposeSimpleDocumentMetas() map[string]string {
return map[string]string{"markdownLineBreakStyle": "document"}
}
// NewTestRenderContext is a helper function to create a RenderContext for testing purpose
// It accepts string (RelativePath), Links, map[string]string (Metas), gitrepo.Repository
func NewTestRenderContext(a ...any) *RenderContext {
if !setting.IsInTesting {
panic("NewTestRenderContext should only be used in testing")
}
ctx := NewRenderContext(context.Background())
for _, v := range a {
switch v := v.(type) {
case string:
ctx = ctx.WithRelativePath(v)
case Links:
ctx = ctx.WithLinks(v)
case map[string]string:
ctx = ctx.WithMetas(v)
case gitrepo.Repository:
ctx = ctx.WithRepoFacade(v)
default:
panic(fmt.Sprintf("unknown type %T", v))
}
}
return ctx
}