gitea/modules/markup/renderer.go

91 lines
2.4 KiB
Go

// Copyright 2017 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package markup
import (
"bytes"
"io"
"path/filepath"
"strings"
"code.gitea.io/gitea/modules/setting"
)
// 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, input io.Reader) 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(filepath.Ext(filename))
return extRenderers[extension]
}
// DetectRendererType detects the markup type of the content
func DetectRendererType(filename string, input io.Reader) string {
buf, err := io.ReadAll(input)
if err != nil {
return ""
}
for _, renderer := range renderers {
if detector, ok := renderer.(RendererContentDetector); ok && detector.CanRender(filename, bytes.NewReader(buf)) {
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
}