gitea/modules/markup/render.go
2025-10-23 08:01:38 +00:00

325 lines
9.9 KiB
Go

// Copyright 2024 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package markup
import (
"context"
"fmt"
"html/template"
"io"
"net/url"
"strconv"
"strings"
"time"
"code.gitea.io/gitea/modules/htmlutil"
"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 {
// Gitea will emit some additional 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.
DisableAdditionalAttributes bool
}
type RenderOptions struct {
UseAbsoluteLink bool
// 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
// user&repo, format&style&regexp (for external issue pattern), teams&org (for mention)
// RefTypeNameSubURL (for iframe&asciicast)
// markupAllowShortIssuePattern
// markdownNewLineHardBreak
Metas map[string]string
// used by external render. the router "/org/repo/render/..." will output the rendered content in a standalone page
InStandalonePage bool
}
// RenderContext represents a render context
type RenderContext struct {
ctx context.Context
// the context might be used by the "render" function, but it might also be used by "postProcess" function
usedByRender bool
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, RenderHelper: &SimpleRenderHelper{}}
}
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) 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) WithUseAbsoluteLink(v bool) *RenderContext {
ctx.RenderOptions.UseAbsoluteLink = v
return ctx
}
func (ctx *RenderContext) WithHelper(helper RenderHelper) *RenderContext {
ctx.RenderHelper = helper
return ctx
}
// FindRendererByContext finds renderer by RenderContext
// TODO: it should be merged with other similar functions like GetRendererByFileName, DetectMarkupTypeByFileName, etc
func FindRendererByContext(ctx *RenderContext) (Renderer, error) {
if ctx.RenderOptions.MarkupType == "" && ctx.RenderOptions.RelativePath != "" {
ctx.RenderOptions.MarkupType = DetectMarkupTypeByFileName(ctx.RenderOptions.RelativePath)
if ctx.RenderOptions.MarkupType == "" {
return nil, util.NewInvalidArgumentErrorf("unsupported file to render: %q", ctx.RenderOptions.RelativePath)
}
}
renderer := renderers[ctx.RenderOptions.MarkupType]
if renderer == nil {
return nil, util.NewNotExistErrorf("unsupported markup type: %q", ctx.RenderOptions.MarkupType)
}
return renderer, nil
}
func RendererNeedPostProcess(renderer Renderer) bool {
if r, ok := renderer.(PostProcessRenderer); ok && r.NeedPostProcess() {
return true
}
return false
}
// Render renders markup file to HTML with all specific handling stuff.
func Render(ctx *RenderContext, input io.Reader, output io.Writer) error {
renderer, err := FindRendererByContext(ctx)
if err != nil {
return err
}
return RenderWithRenderer(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, sandbox string, output io.Writer) error {
src := fmt.Sprintf("%s/%s/%s/render/%s/%s", setting.AppSubURL,
url.PathEscape(ctx.RenderOptions.Metas["user"]),
url.PathEscape(ctx.RenderOptions.Metas["repo"]),
util.PathEscapeSegments(ctx.RenderOptions.Metas["RefTypeNameSubURL"]),
util.PathEscapeSegments(ctx.RenderOptions.RelativePath),
)
var sandboxAttrValue template.HTML
if sandbox != "" {
sandboxAttrValue = htmlutil.HTMLFormat(`sandbox="%s"`, sandbox)
}
iframe := htmlutil.HTMLFormat(`<iframe data-src="%s" class="external-render-iframe" %s></iframe>`, src, sandboxAttrValue)
_, err := io.WriteString(output, string(iframe))
return err
}
func pipes() (io.ReadCloser, io.WriteCloser, func()) {
pr, pw := io.Pipe()
return pr, pw, func() {
_ = pr.Close()
_ = pw.Close()
}
}
func getExternalRendererOptions(renderer Renderer) (ret ExternalRendererOptions, _ bool) {
if externalRender, ok := renderer.(ExternalRenderer); ok {
return externalRender.GetExternalRendererOptions(), true
}
return ret, false
}
func RenderWithRenderer(ctx *RenderContext, renderer Renderer, input io.Reader, output io.Writer) error {
var extraHeadHTML template.HTML
if extOpts, ok := getExternalRendererOptions(renderer); ok && extOpts.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, extOpts.ContentSandbox, output)
}
// else: this is a standalone page, fallthrough to the real rendering, and add extra JS/CSS
extraStyleHref := setting.AppSubURL + "/assets/css/external-render-iframe.css"
extraScriptSrc := setting.AppSubURL + "/assets/js/external-render-iframe.js"
// "<script>" must go before "<link>", to make Golang's http.DetectContentType() can still recognize the content as "text/html"
extraHeadHTML = htmlutil.HTMLFormat(`<script src="%s"></script><link rel="stylesheet" href="%s">`, extraScriptSrc, extraStyleHref)
}
ctx.usedByRender = true
if ctx.RenderHelper != nil {
defer ctx.RenderHelper.CleanUp()
}
finalProcessor := ctx.RenderInternal.Init(output, extraHeadHTML)
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.GetExternalRendererOptions().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 RendererNeedPostProcess(renderer) {
err = PostProcessDefault(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(renderHelpFuncs *RenderHelperFuncs) {
DefaultRenderHelperFuncs = renderHelpFuncs
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 {
// TODO: there is no separate config option for "simple document" rendering, so temporarily use the same config as "repo file"
return map[string]string{"markdownNewLineHardBreak": strconv.FormatBool(setting.Markdown.RenderOptionsRepoFile.NewLineHardBreak)}
}
type TestRenderHelper struct {
ctx *RenderContext
BaseLink string
}
func (r *TestRenderHelper) CleanUp() {}
func (r *TestRenderHelper) IsCommitIDExisting(commitID string) bool {
return strings.HasPrefix(commitID, "65f1bf2") //|| strings.HasPrefix(commitID, "88fc37a")
}
func (r *TestRenderHelper) ResolveLink(link, preferLinkType string) string {
linkType, link := ParseRenderedLink(link, preferLinkType)
switch linkType {
case LinkTypeRoot:
return r.ctx.ResolveLinkRoot(link)
default:
return r.ctx.ResolveLinkRelative(r.BaseLink, "", link)
}
}
var _ RenderHelper = (*TestRenderHelper)(nil)
// NewTestRenderContext is a helper function to create a RenderContext for testing purpose
// It accepts string (BaseLink), map[string]string (Metas)
func NewTestRenderContext(baseLinkOrMetas ...any) *RenderContext {
if !setting.IsInTesting {
panic("NewTestRenderContext should only be used in testing")
}
helper := &TestRenderHelper{}
ctx := NewRenderContext(context.Background()).WithHelper(helper)
helper.ctx = ctx
for _, v := range baseLinkOrMetas {
switch v := v.(type) {
case string:
helper.BaseLink = v
case map[string]string:
ctx = ctx.WithMetas(v)
default:
panic(fmt.Sprintf("unknown type %T", v))
}
}
return ctx
}