first-commit

modules/markup/renderer.go

@@ -0,0 +1,86 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markup
+
+import (
+	"io"
+	"path"
+	"strings"
+
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/typesniffer"
+)
+
+// 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
+}
+
+// ExternalRenderer 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, sniffedType typesniffer.SniffedType, prefetchBuf []byte) 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(path.Ext(filename))
+	return extRenderers[extension]
+}
+
+// DetectRendererType detects the markup type of the content
+func DetectRendererType(filename string, sniffedType typesniffer.SniffedType, prefetchBuf []byte) string {
+	for _, renderer := range renderers {
+		if detector, ok := renderer.(RendererContentDetector); ok && detector.CanRender(filename, sniffedType, prefetchBuf) {
+			return renderer.Name()
+		}
+	}
+	return ""
+}
+
+// DetectMarkupTypeByFileName returns the possible markup format type via the filename
+func DetectMarkupTypeByFileName(filename string) string {
+	if parser := GetRendererByFileName(filename); parser != nil {
+		return parser.Name()
+	}
+	return ""
+}
+
+func PreviewableExtensions() []string {
+	extensions := make([]string, 0, len(extRenderers))
+	for extension := range extRenderers {
+		extensions = append(extensions, extension)
+	}
+	return extensions
+}