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mirror of https://github.com/go-gitea/gitea.git synced 2024-12-04 14:46:57 -05:00
gitea/modules/markup/render.go
wxiaoguang 3f9c3e7bc3
Refactor render system ()
There were too many patches to the Render system, it's really difficult
to make further improvements.

This PR clears the legacy problems and fix TODOs.

1. Rename `RenderContext.Type` to `RenderContext.MarkupType` to clarify
its usage.
2. Use `ContentMode` to replace `meta["mode"]` and `IsWiki`, to clarify
the rendering behaviors.
3. Use "wiki" mode instead of "mode=gfm + wiki=true"
4. Merge `renderByType` and `renderByFile`
5. Add more comments

----

The problem of "mode=document": in many cases it is not set, so many
non-comment places use comment's hard line break incorrectly
2024-11-14 05:02:11 +00:00

235 lines
7.1 KiB
Go

// Copyright 2024 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package markup
import (
"context"
"fmt"
"io"
"net/url"
"strings"
"sync"
"code.gitea.io/gitea/modules/git"
"code.gitea.io/gitea/modules/gitrepo"
"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 RenderContentMode string
const (
RenderContentAsDefault RenderContentMode = "" // empty means "default", no special handling, maybe just a simple "document"
RenderContentAsComment RenderContentMode = "comment"
RenderContentAsTitle RenderContentMode = "title"
RenderContentAsWiki RenderContentMode = "wiki"
)
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
}
// RenderContext represents a render context
type RenderContext struct {
Ctx context.Context
RelativePath string // relative path from tree root of the branch
// eg: "orgmode", "asciicast", "console"
// for file mode, it could be left as empty, and will be detected by file extension in RelativePath
MarkupType string
// what the content will be used for: eg: for comment or for wiki? or just render a file?
ContentMode RenderContentMode
Links Links // special link references for rendering, especially when there is a branch/tree path
Metas map[string]string // user&repo, format&style&regexp (for external issue pattern), teams&org (for mention), BranchNameSubURL(for iframe&asciicast)
DefaultLink string // TODO: need to figure out
GitRepo *git.Repository
Repo gitrepo.Repository
ShaExistCache map[string]bool
cancelFn func()
SidebarTocNode ast.Node
RenderMetaAs RenderMetaMode
InStandalonePage bool // used by external render. the router "/org/repo/render/..." will output the rendered content in a standalone page
}
// 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()
}
}
// Render renders markup file to HTML with all specific handling stuff.
func Render(ctx *RenderContext, input io.Reader, output io.Writer) error {
if ctx.MarkupType == "" && ctx.RelativePath != "" {
ctx.MarkupType = DetectMarkupTypeByFileName(ctx.RelativePath)
if ctx.MarkupType == "" {
return util.NewInvalidArgumentErrorf("unsupported file to render: %q", ctx.RelativePath)
}
}
renderer := renderers[ctx.MarkupType]
if renderer == nil {
return util.NewInvalidArgumentErrorf("unsupported markup type: %q", ctx.MarkupType)
}
if ctx.RelativePath != "" {
if externalRender, ok := renderer.(ExternalRenderer); ok && externalRender.DisplayInIFrame() {
if !ctx.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.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 = util.NopCloser{Writer: 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
}
// 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
}
}
}