// Copyright 2022 The Gitea Authors. All rights reserved.// SPDX-License-Identifier: MIT package charset import ( "fmt" "io" "golang.org/x/net/html") // HTMLStreamer represents a SAX-like interface for HTMLtype HTMLStreamer interface { Error(err error) error Doctype(data string) error Comment(data string) error StartTag(data string, attrs ...html.Attribute) error SelfClosingTag(data string, attrs ...html.Attribute) error EndTag(data string) error Text(data string) error} // PassthroughHTMLStreamer is a passthrough streamertype PassthroughHTMLStreamer struct { next HTMLStreamer} func NewPassthroughStreamer(next HTMLStreamer) *PassthroughHTMLStreamer { return &PassthroughHTMLStreamer{next: next}} var _ (HTMLStreamer) = &PassthroughHTMLStreamer{} // Error tells the next streamer in line that there is an errorfunc (p *PassthroughHTMLStreamer) Error(err error) error { return p.next.Error(err)} // Doctype tells the next streamer what the doctype isfunc (p *PassthroughHTMLStreamer) Doctype(data string) error { return p.next.Doctype(data)} // Comment tells the next streamer there is a commentfunc (p *PassthroughHTMLStreamer) Comment(data string) error { return p.next.Comment(data)} // StartTag tells the next streamer there is a starting tagfunc (p *PassthroughHTMLStreamer) StartTag(data string, attrs ...html.Attribute) error { return p.next.StartTag(data, attrs...)} // SelfClosingTag tells the next streamer there is a self-closing tagfunc (p *PassthroughHTMLStreamer) SelfClosingTag(data string, attrs ...html.Attribute) error { return p.next.SelfClosingTag(data, attrs...)} // EndTag tells the next streamer there is a end tagfunc (p *PassthroughHTMLStreamer) EndTag(data string) error { return p.next.EndTag(data)} // Text tells the next streamer there is a textfunc (p *PassthroughHTMLStreamer) Text(data string) error { return p.next.Text(data)} // HTMLStreamWriter acts as a writing sinktype HTMLStreamerWriter struct { io.Writer err error} // Write implements io.Writerfunc (h *HTMLStreamerWriter) Write(data []byte) (int, error) { if h.err != nil { return 0, h.err } return h.Writer.Write(data)} // Write implements io.StringWriterfunc (h *HTMLStreamerWriter) WriteString(data string) (int, error) { if h.err != nil { return 0, h.err } return h.Writer.Write([]byte(data))} // Error tells the next streamer in line that there is an errorfunc (h *HTMLStreamerWriter) Error(err error) error { if h.err == nil { h.err = err } return h.err} // Doctype tells the next streamer what the doctype isfunc (h *HTMLStreamerWriter) Doctype(data string) error { _, h.err = h.WriteString("<!DOCTYPE " + data + ">") return h.err} // Comment tells the next streamer there is a commentfunc (h *HTMLStreamerWriter) Comment(data string) error { _, h.err = h.WriteString("<!--" + data + "-->") return h.err} // StartTag tells the next streamer there is a starting tagfunc (h *HTMLStreamerWriter) StartTag(data string, attrs ...html.Attribute) error { return h.startTag(data, attrs, false)} // SelfClosingTag tells the next streamer there is a self-closing tagfunc (h *HTMLStreamerWriter) SelfClosingTag(data string, attrs ...html.Attribute) error { return h.startTag(data, attrs, true)} func (h *HTMLStreamerWriter) startTag(data string, attrs []html.Attribute, selfclosing bool) error { if _, h.err = h.WriteString("<" + data); h.err != nil { return h.err } for _, attr := range attrs { if _, h.err = h.WriteString(" " + attr.Key + "=\"" + html.EscapeString(attr.Val) + "\""); h.err != nil { return h.err } } if selfclosing { if _, h.err = h.WriteString("/>"); h.err != nil { return h.err } } else { if _, h.err = h.WriteString(">"); h.err != nil { return h.err } } return h.err} // EndTag tells the next streamer there is a end tagfunc (h *HTMLStreamerWriter) EndTag(data string) error { _, h.err = h.WriteString("</" + data + ">") return h.err} // Text tells the next streamer there is a textfunc (h *HTMLStreamerWriter) Text(data string) error { _, h.err = h.WriteString(html.EscapeString(data)) return h.err} // StreamHTML streams an html to a provided streamerfunc StreamHTML(source io.Reader, streamer HTMLStreamer) error { tokenizer := html.NewTokenizer(source) for { tt := tokenizer.Next() switch tt { case html.ErrorToken: if tokenizer.Err() != io.EOF { return tokenizer.Err() } return nil case html.DoctypeToken: token := tokenizer.Token() if err := streamer.Doctype(token.Data); err != nil { return err } case html.CommentToken: token := tokenizer.Token() if err := streamer.Comment(token.Data); err != nil { return err } case html.StartTagToken: token := tokenizer.Token() if err := streamer.StartTag(token.Data, token.Attr...); err != nil { return err } case html.SelfClosingTagToken: token := tokenizer.Token() if err := streamer.StartTag(token.Data, token.Attr...); err != nil { return err } case html.EndTagToken: token := tokenizer.Token() if err := streamer.EndTag(token.Data); err != nil { return err } case html.TextToken: token := tokenizer.Token() if err := streamer.Text(token.Data); err != nil { return err } default: return fmt.Errorf("unknown type of token: %d", tt) } }}
// Copyright 2022 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package charset
import (
"fmt"
"io"
"golang.org/x/net/html"
)
// HTMLStreamer represents a SAX-like interface for HTML
type HTMLStreamer interface {
Error(err error) error
Doctype(data string) error
Comment(data string) error
StartTag(data string, attrs ...html.Attribute) error
SelfClosingTag(data string, attrs ...html.Attribute) error
EndTag(data string) error
Text(data string) error
}
// PassthroughHTMLStreamer is a passthrough streamer
type PassthroughHTMLStreamer struct {
next HTMLStreamer
}
func NewPassthroughStreamer(next HTMLStreamer) *PassthroughHTMLStreamer {
return &PassthroughHTMLStreamer{next: next}
}
var _ (HTMLStreamer) = &PassthroughHTMLStreamer{}
// Error tells the next streamer in line that there is an error
func (p *PassthroughHTMLStreamer) Error(err error) error {
return p.next.Error(err)
}
// Doctype tells the next streamer what the doctype is
func (p *PassthroughHTMLStreamer) Doctype(data string) error {
return p.next.Doctype(data)
}
// Comment tells the next streamer there is a comment
func (p *PassthroughHTMLStreamer) Comment(data string) error {
return p.next.Comment(data)
}
// StartTag tells the next streamer there is a starting tag
func (p *PassthroughHTMLStreamer) StartTag(data string, attrs ...html.Attribute) error {
return p.next.StartTag(data, attrs...)
}
// SelfClosingTag tells the next streamer there is a self-closing tag
func (p *PassthroughHTMLStreamer) SelfClosingTag(data string, attrs ...html.Attribute) error {
return p.next.SelfClosingTag(data, attrs...)
}
// EndTag tells the next streamer there is a end tag
func (p *PassthroughHTMLStreamer) EndTag(data string) error {
return p.next.EndTag(data)
}
// Text tells the next streamer there is a text
func (p *PassthroughHTMLStreamer) Text(data string) error {
return p.next.Text(data)
}
// HTMLStreamWriter acts as a writing sink
type HTMLStreamerWriter struct {
io.Writer
err error
}
// Write implements io.Writer
func (h *HTMLStreamerWriter) Write(data []byte) (int, error) {
if h.err != nil {
return 0, h.err
}
return h.Writer.Write(data)
}
// Write implements io.StringWriter
func (h *HTMLStreamerWriter) WriteString(data string) (int, error) {
if h.err != nil {
return 0, h.err
}
return h.Writer.Write([]byte(data))
}
// Error tells the next streamer in line that there is an error
func (h *HTMLStreamerWriter) Error(err error) error {
if h.err == nil {
h.err = err
}
return h.err
}
// Doctype tells the next streamer what the doctype is
func (h *HTMLStreamerWriter) Doctype(data string) error {
_, h.err = h.WriteString("<!DOCTYPE " + data + ">")
return h.err
}
// Comment tells the next streamer there is a comment
func (h *HTMLStreamerWriter) Comment(data string) error {
_, h.err = h.WriteString("<!--" + data + "-->")
return h.err
}
// StartTag tells the next streamer there is a starting tag
func (h *HTMLStreamerWriter) StartTag(data string, attrs ...html.Attribute) error {
return h.startTag(data, attrs, false)
}
// SelfClosingTag tells the next streamer there is a self-closing tag
func (h *HTMLStreamerWriter) SelfClosingTag(data string, attrs ...html.Attribute) error {
return h.startTag(data, attrs, true)
}
func (h *HTMLStreamerWriter) startTag(data string, attrs []html.Attribute, selfclosing bool) error {
if _, h.err = h.WriteString("<" + data); h.err != nil {
return h.err
}
for _, attr := range attrs {
if _, h.err = h.WriteString(" " + attr.Key + "=\"" + html.EscapeString(attr.Val) + "\""); h.err != nil {
return h.err
}
}
if selfclosing {
if _, h.err = h.WriteString("/>"); h.err != nil {
return h.err
}
} else {
if _, h.err = h.WriteString(">"); h.err != nil {
return h.err
}
}
return h.err
}
// EndTag tells the next streamer there is a end tag
func (h *HTMLStreamerWriter) EndTag(data string) error {
_, h.err = h.WriteString("</" + data + ">")
return h.err
}
// Text tells the next streamer there is a text
func (h *HTMLStreamerWriter) Text(data string) error {
_, h.err = h.WriteString(html.EscapeString(data))
return h.err
}
// StreamHTML streams an html to a provided streamer
func StreamHTML(source io.Reader, streamer HTMLStreamer) error {
tokenizer := html.NewTokenizer(source)
for {
tt := tokenizer.Next()
switch tt {
case html.ErrorToken:
if tokenizer.Err() != io.EOF {
return tokenizer.Err()
}
return nil
case html.DoctypeToken:
token := tokenizer.Token()
if err := streamer.Doctype(token.Data); err != nil {
return err
}
case html.CommentToken:
token := tokenizer.Token()
if err := streamer.Comment(token.Data); err != nil {
return err
}
case html.StartTagToken:
token := tokenizer.Token()
if err := streamer.StartTag(token.Data, token.Attr...); err != nil {
return err
}
case html.SelfClosingTagToken:
token := tokenizer.Token()
if err := streamer.StartTag(token.Data, token.Attr...); err != nil {
return err
}
case html.EndTagToken:
token := tokenizer.Token()
if err := streamer.EndTag(token.Data); err != nil {
return err
}
case html.TextToken:
token := tokenizer.Token()
if err := streamer.Text(token.Data); err != nil {
return err
}
default:
return fmt.Errorf("unknown type of token: %d", tt)
}
}
}