初始提交: Gitea 项目代码

modules/markup/renderer.go

@@ -0,0 +1,108 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markup
+
+import (
+	"io"
+	"path"
+	"strings"
+
+	"gitea.dev/modules/setting"
+	"gitea.dev/modules/typesniffer"
+)
+
+// Renderer defines an interface for rendering markup file to HTML
+type Renderer interface {
+	Name() string // markup format name, also the renderer type, also the external tool name
+	FileNamePatterns() []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
+}
+
+type ExternalRendererOptions struct {
+	SanitizerDisabled bool
+	DisplayInIframe   bool
+	ContentSandbox    string
+}
+
+// ExternalRenderer defines an interface for external renderers
+type ExternalRenderer interface {
+	GetExternalRendererOptions() ExternalRendererOptions
+}
+
+// RendererContentDetector detects if the content can be rendered
+// by specified renderer
+type RendererContentDetector interface {
+	CanRender(filename string, sniffedType typesniffer.SniffedType, prefetchBuf []byte) bool
+}
+
+var (
+	fileNameRenderers = make(map[string]Renderer)
+	renderers         = make(map[string]Renderer)
+)
+
+// RegisterRenderer registers a new markup file renderer
+func RegisterRenderer(renderer Renderer) {
+	// TODO: need to handle conflicts
+	renderers[renderer.Name()] = renderer
+}
+
+func RefreshFileNamePatterns() {
+	// TODO: need to handle conflicts
+	fileNameRenderers = make(map[string]Renderer)
+	for _, renderer := range renderers {
+		for _, ext := range renderer.FileNamePatterns() {
+			fileNameRenderers[strings.ToLower(ext)] = renderer
+		}
+	}
+}
+
+func DetectRendererTypeByFilename(filename string) Renderer {
+	basename := path.Base(strings.ToLower(filename))
+	ext1 := path.Ext(basename)
+	if renderer := fileNameRenderers[basename]; renderer != nil {
+		return renderer
+	}
+	if renderer := fileNameRenderers["*"+ext1]; renderer != nil {
+		return renderer
+	}
+	if basename, ok := strings.CutSuffix(basename, ext1); ok {
+		ext2 := path.Ext(basename)
+		if renderer := fileNameRenderers["*"+ext2+ext1]; renderer != nil {
+			return renderer
+		}
+	}
+	return nil
+}
+
+// DetectRendererTypeByPrefetch detects the markup type of the content
+func DetectRendererTypeByPrefetch(filename string, sniffedType typesniffer.SniffedType, prefetchBuf []byte) string {
+	if filename != "" {
+		byExt := DetectRendererTypeByFilename(filename)
+		if byExt != nil {
+			return byExt.Name()
+		}
+	}
+	for _, renderer := range renderers {
+		if detector, ok := renderer.(RendererContentDetector); ok && detector.CanRender(filename, sniffedType, prefetchBuf) {
+			return renderer.Name()
+		}
+	}
+	return ""
+}
+
+func PreviewableExtensions() []string {
+	exts := make([]string, 0, len(fileNameRenderers))
+	for p := range fileNameRenderers {
+		if s, ok := strings.CutPrefix(p, "*"); ok {
+			exts = append(exts, s)
+		}
+	}
+	return exts
+}