1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
// 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)
}
}
}
|
