forked from tdewolff/minify
/
html.go
467 lines (438 loc) · 16.1 KB
/
html.go
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
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
// Package html minifies HTML5 following the specifications at http://www.w3.org/TR/html5/syntax.html.
package html // import "github.com/tdewolff/minify/html"
import (
"bytes"
"io"
"github.com/tdewolff/minify"
"github.com/tdewolff/parse"
"github.com/tdewolff/parse/buffer"
"github.com/tdewolff/parse/html"
)
var (
gtBytes = []byte(">")
isBytes = []byte("=")
spaceBytes = []byte(" ")
doctypeBytes = []byte("<!doctype html>")
jsMimeBytes = []byte("text/javascript")
cssMimeBytes = []byte("text/css")
htmlMimeBytes = []byte("text/html")
svgMimeBytes = []byte("image/svg+xml")
mathMimeBytes = []byte("application/mathml+xml")
dataSchemeBytes = []byte("data:")
jsSchemeBytes = []byte("javascript:")
httpBytes = []byte("http")
)
////////////////////////////////////////////////////////////////
// DefaultMinifier is the default minifier.
var DefaultMinifier = &Minifier{}
// Minifier is an HTML minifier.
type Minifier struct {
KeepConditionalComments bool
KeepDefaultAttrVals bool
KeepDocumentTags bool
KeepEndTags bool
KeepWhitespace bool
}
// Minify minifies HTML data, it reads from r and writes to w.
func Minify(m *minify.M, w io.Writer, r io.Reader, params map[string]string) error {
return DefaultMinifier.Minify(m, w, r, params)
}
// Minify minifies HTML data, it reads from r and writes to w.
func (o *Minifier) Minify(m *minify.M, w io.Writer, r io.Reader, _ map[string]string) error {
var rawTagHash html.Hash
var rawTagMediatype []byte
omitSpace := true // if true the next leading space is omitted
inPre := false
defaultScriptType := jsMimeBytes
defaultScriptParams := map[string]string(nil)
defaultStyleType := cssMimeBytes
defaultStyleParams := map[string]string(nil)
defaultInlineStyleParams := map[string]string{"inline": "1"}
attrMinifyBuffer := buffer.NewWriter(make([]byte, 0, 64))
attrByteBuffer := make([]byte, 0, 64)
l := html.NewLexer(r)
defer l.Restore()
tb := NewTokenBuffer(l)
for {
t := *tb.Shift()
SWITCH:
switch t.TokenType {
case html.ErrorToken:
if l.Err() == io.EOF {
return nil
}
return l.Err()
case html.DoctypeToken:
if _, err := w.Write(doctypeBytes); err != nil {
return err
}
case html.CommentToken:
if o.KeepConditionalComments && len(t.Text) > 6 && (bytes.HasPrefix(t.Text, []byte("[if ")) || bytes.Equal(t.Text, []byte("[endif]")) || bytes.Equal(t.Text, []byte("<![endif]"))) {
// [if ...] is always 7 or more characters, [endif] is only encountered for downlevel-revealed
// see https://msdn.microsoft.com/en-us/library/ms537512(v=vs.85).aspx#syntax
if bytes.HasPrefix(t.Data, []byte("<!--[if ")) && len(t.Data) > len("<!--[if ]><![endif]-->") { // downlevel-hidden
begin := bytes.IndexByte(t.Data, '>') + 1
end := len(t.Data) - len("<![endif]-->")
if _, err := w.Write(t.Data[:begin]); err != nil {
return err
}
if err := o.Minify(m, w, buffer.NewReader(t.Data[begin:end]), nil); err != nil {
return err
}
if _, err := w.Write(t.Data[end:]); err != nil {
return err
}
} else if _, err := w.Write(t.Data); err != nil { // downlevel-revealed or short downlevel-hidden
return err
}
}
case html.SvgToken:
if err := m.MinifyMimetype(svgMimeBytes, w, buffer.NewReader(t.Data), nil); err != nil {
if err != minify.ErrNotExist {
return err
} else if _, err := w.Write(t.Data); err != nil {
return err
}
}
case html.MathToken:
if err := m.MinifyMimetype(mathMimeBytes, w, buffer.NewReader(t.Data), nil); err != nil {
if err != minify.ErrNotExist {
return err
} else if _, err := w.Write(t.Data); err != nil {
return err
}
}
case html.TextToken:
// CSS and JS minifiers for inline code
if rawTagHash != 0 {
if rawTagHash == html.Style || rawTagHash == html.Script || rawTagHash == html.Iframe {
var mimetype []byte
var params map[string]string
if rawTagHash == html.Iframe {
mimetype = htmlMimeBytes
} else if len(rawTagMediatype) > 0 {
mimetype, params = parse.Mediatype(rawTagMediatype)
} else if rawTagHash == html.Script {
mimetype = defaultScriptType
params = defaultScriptParams
} else if rawTagHash == html.Style {
mimetype = defaultStyleType
params = defaultStyleParams
}
if err := m.MinifyMimetype(mimetype, w, buffer.NewReader(t.Data), params); err != nil {
if err != minify.ErrNotExist {
return err
} else if _, err := w.Write(t.Data); err != nil {
return err
}
}
} else if _, err := w.Write(t.Data); err != nil {
return err
}
} else if inPre {
if _, err := w.Write(t.Data); err != nil {
return err
}
} else {
t.Data = parse.ReplaceMultipleWhitespace(t.Data)
// whitespace removal; trim left
if omitSpace && (t.Data[0] == ' ' || t.Data[0] == '\n') {
t.Data = t.Data[1:]
}
// whitespace removal; trim right
omitSpace = false
if len(t.Data) == 0 {
omitSpace = true
} else if t.Data[len(t.Data)-1] == ' ' || t.Data[len(t.Data)-1] == '\n' {
omitSpace = true
i := 0
for {
next := tb.Peek(i)
// trim if EOF, text token with leading whitespace or block token
if next.TokenType == html.ErrorToken {
t.Data = t.Data[:len(t.Data)-1]
omitSpace = false
break
} else if next.TokenType == html.TextToken {
// this only happens when a comment, doctype or phrasing end tag (only for !o.KeepWhitespace) was in between
// remove if the text token starts with a whitespace
if len(next.Data) > 0 && parse.IsWhitespace(next.Data[0]) {
t.Data = t.Data[:len(t.Data)-1]
omitSpace = false
}
break
} else if next.TokenType == html.StartTagToken || next.TokenType == html.EndTagToken {
if o.KeepWhitespace {
break
}
// remove when followed up by a block tag
if next.Traits&nonPhrasingTag != 0 {
t.Data = t.Data[:len(t.Data)-1]
omitSpace = false
break
} else if next.TokenType == html.StartTagToken {
break
}
}
i++
}
}
if _, err := w.Write(t.Data); err != nil {
return err
}
}
case html.StartTagToken, html.EndTagToken:
rawTagHash = 0
hasAttributes := false
if t.TokenType == html.StartTagToken {
if next := tb.Peek(0); next.TokenType == html.AttributeToken {
hasAttributes = true
}
if t.Traits&rawTag != 0 {
// ignore empty script and style tags
if !hasAttributes && (t.Hash == html.Script || t.Hash == html.Style) {
if next := tb.Peek(1); next.TokenType == html.EndTagToken {
tb.Shift()
tb.Shift()
break
}
}
rawTagHash = t.Hash
rawTagMediatype = nil
}
} else if t.Hash == html.Template {
omitSpace = true // EndTagToken
}
if t.Hash == html.Pre {
inPre = t.TokenType == html.StartTagToken
}
// remove superfluous tags, except for html, head and body tags when KeepDocumentTags is set
if !hasAttributes && (!o.KeepDocumentTags && (t.Hash == html.Html || t.Hash == html.Head || t.Hash == html.Body) || t.Hash == html.Colgroup) {
break
} else if t.TokenType == html.EndTagToken {
if !o.KeepEndTags {
if t.Hash == html.Thead || t.Hash == html.Tbody || t.Hash == html.Tfoot || t.Hash == html.Tr || t.Hash == html.Th || t.Hash == html.Td ||
t.Hash == html.Optgroup || t.Hash == html.Option || t.Hash == html.Dd || t.Hash == html.Dt ||
t.Hash == html.Li || t.Hash == html.Rb || t.Hash == html.Rt || t.Hash == html.Rtc || t.Hash == html.Rp {
break
} else if t.Hash == html.P {
i := 0
for {
next := tb.Peek(i)
i++
// continue if text token is empty or whitespace
if next.TokenType == html.TextToken && parse.IsAllWhitespace(next.Data) {
continue
}
if next.TokenType == html.ErrorToken || next.TokenType == html.EndTagToken && next.Traits&keepPTag == 0 || next.TokenType == html.StartTagToken && next.Traits&omitPTag != 0 {
break SWITCH // omit p end tag
}
break
}
}
}
if o.KeepWhitespace || t.Traits&objectTag != 0 {
omitSpace = false
} else if t.Traits&nonPhrasingTag != 0 {
omitSpace = true // omit spaces after block elements
}
if len(t.Data) > 3+len(t.Text) {
t.Data[2+len(t.Text)] = '>'
t.Data = t.Data[:3+len(t.Text)]
}
if _, err := w.Write(t.Data); err != nil {
return err
}
break
}
if o.KeepWhitespace || t.Traits&objectTag != 0 {
omitSpace = false
} else if t.Traits&nonPhrasingTag != 0 {
omitSpace = true // omit spaces after block elements
}
if _, err := w.Write(t.Data); err != nil {
return err
}
if hasAttributes {
if t.Hash == html.Meta {
attrs := tb.Attributes(html.Content, html.Http_Equiv, html.Charset, html.Name)
if content := attrs[0]; content != nil {
if httpEquiv := attrs[1]; httpEquiv != nil {
if charset := attrs[2]; charset == nil && parse.EqualFold(httpEquiv.AttrVal, []byte("content-type")) {
content.AttrVal = minify.Mediatype(content.AttrVal)
if bytes.Equal(content.AttrVal, []byte("text/html;charset=utf-8")) {
httpEquiv.Text = nil
content.Text = []byte("charset")
content.Hash = html.Charset
content.AttrVal = []byte("utf-8")
}
} else if parse.EqualFold(httpEquiv.AttrVal, []byte("content-style-type")) {
content.AttrVal = minify.Mediatype(content.AttrVal)
defaultStyleType, defaultStyleParams = parse.Mediatype(content.AttrVal)
if defaultStyleParams != nil {
defaultInlineStyleParams = defaultStyleParams
defaultInlineStyleParams["inline"] = "1"
} else {
defaultInlineStyleParams = map[string]string{"inline": "1"}
}
} else if parse.EqualFold(httpEquiv.AttrVal, []byte("content-script-type")) {
content.AttrVal = minify.Mediatype(content.AttrVal)
defaultScriptType, defaultScriptParams = parse.Mediatype(content.AttrVal)
}
}
if name := attrs[3]; name != nil {
if parse.EqualFold(name.AttrVal, []byte("keywords")) {
content.AttrVal = bytes.Replace(content.AttrVal, []byte(", "), []byte(","), -1)
} else if parse.EqualFold(name.AttrVal, []byte("viewport")) {
content.AttrVal = bytes.Replace(content.AttrVal, []byte(" "), []byte(""), -1)
for i := 0; i < len(content.AttrVal); i++ {
if content.AttrVal[i] == '=' && i+2 < len(content.AttrVal) {
i++
if n := parse.Number(content.AttrVal[i:]); n > 0 {
minNum := minify.Number(content.AttrVal[i:i+n], -1)
if len(minNum) < n {
copy(content.AttrVal[i:i+len(minNum)], minNum)
copy(content.AttrVal[i+len(minNum):], content.AttrVal[i+n:])
content.AttrVal = content.AttrVal[:len(content.AttrVal)+len(minNum)-n]
}
i += len(minNum)
}
i-- // mitigate for-loop increase
}
}
}
}
}
} else if t.Hash == html.Script {
attrs := tb.Attributes(html.Src, html.Charset)
if attrs[0] != nil && attrs[1] != nil {
attrs[1].Text = nil
}
}
// write attributes
htmlEqualIdName := false
for {
attr := *tb.Shift()
if attr.TokenType != html.AttributeToken {
break
} else if attr.Text == nil {
continue // removed attribute
}
if t.Hash == html.A && (attr.Hash == html.Id || attr.Hash == html.Name) {
if attr.Hash == html.Id {
if name := tb.Attributes(html.Name)[0]; name != nil && bytes.Equal(attr.AttrVal, name.AttrVal) {
htmlEqualIdName = true
}
} else if htmlEqualIdName {
continue
} else if id := tb.Attributes(html.Id)[0]; id != nil && bytes.Equal(id.AttrVal, attr.AttrVal) {
continue
}
}
val := attr.AttrVal
if len(val) == 0 && (attr.Hash == html.Class ||
attr.Hash == html.Dir ||
attr.Hash == html.Id ||
attr.Hash == html.Lang ||
attr.Hash == html.Name ||
attr.Hash == html.Title ||
attr.Hash == html.Action && t.Hash == html.Form ||
attr.Hash == html.Value && t.Hash == html.Input) {
continue // omit empty attribute values
}
if attr.Traits&caselessAttr != 0 {
val = parse.ToLower(val)
if attr.Hash == html.Enctype || attr.Hash == html.Codetype || attr.Hash == html.Accept || attr.Hash == html.Type && (t.Hash == html.A || t.Hash == html.Link || t.Hash == html.Object || t.Hash == html.Param || t.Hash == html.Script || t.Hash == html.Style || t.Hash == html.Source) {
val = minify.Mediatype(val)
}
}
if rawTagHash != 0 && attr.Hash == html.Type {
rawTagMediatype = parse.Copy(val)
}
// default attribute values can be omitted
if !o.KeepDefaultAttrVals && (attr.Hash == html.Type && (t.Hash == html.Script && bytes.Equal(val, []byte("text/javascript")) ||
t.Hash == html.Style && bytes.Equal(val, []byte("text/css")) ||
t.Hash == html.Link && bytes.Equal(val, []byte("text/css")) ||
t.Hash == html.Input && bytes.Equal(val, []byte("text")) ||
t.Hash == html.Button && bytes.Equal(val, []byte("submit"))) ||
attr.Hash == html.Language && t.Hash == html.Script ||
attr.Hash == html.Method && bytes.Equal(val, []byte("get")) ||
attr.Hash == html.Enctype && bytes.Equal(val, []byte("application/x-www-form-urlencoded")) ||
attr.Hash == html.Colspan && bytes.Equal(val, []byte("1")) ||
attr.Hash == html.Rowspan && bytes.Equal(val, []byte("1")) ||
attr.Hash == html.Shape && bytes.Equal(val, []byte("rect")) ||
attr.Hash == html.Span && bytes.Equal(val, []byte("1")) ||
attr.Hash == html.Clear && bytes.Equal(val, []byte("none")) ||
attr.Hash == html.Frameborder && bytes.Equal(val, []byte("1")) ||
attr.Hash == html.Scrolling && bytes.Equal(val, []byte("auto")) ||
attr.Hash == html.Valuetype && bytes.Equal(val, []byte("data")) ||
attr.Hash == html.Media && t.Hash == html.Style && bytes.Equal(val, []byte("all"))) {
continue
}
// CSS and JS minifiers for attribute inline code
if attr.Hash == html.Style {
attrMinifyBuffer.Reset()
if err := m.MinifyMimetype(defaultStyleType, attrMinifyBuffer, buffer.NewReader(val), defaultInlineStyleParams); err == nil {
val = attrMinifyBuffer.Bytes()
} else if err != minify.ErrNotExist {
return err
}
if len(val) == 0 {
continue
}
} else if len(attr.Text) > 2 && attr.Text[0] == 'o' && attr.Text[1] == 'n' {
if len(val) >= 11 && parse.EqualFold(val[:11], jsSchemeBytes) {
val = val[11:]
}
attrMinifyBuffer.Reset()
if err := m.MinifyMimetype(defaultScriptType, attrMinifyBuffer, buffer.NewReader(val), defaultScriptParams); err == nil {
val = attrMinifyBuffer.Bytes()
} else if err != minify.ErrNotExist {
return err
}
if len(val) == 0 {
continue
}
} else if len(val) > 5 && attr.Traits&urlAttr != 0 { // anchors are already handled
if parse.EqualFold(val[:4], httpBytes) {
if val[4] == ':' {
if m.URL != nil && m.URL.Scheme == "http" {
val = val[5:]
} else {
parse.ToLower(val[:4])
}
} else if (val[4] == 's' || val[4] == 'S') && val[5] == ':' {
if m.URL != nil && m.URL.Scheme == "https" {
val = val[6:]
} else {
parse.ToLower(val[:5])
}
}
} else if parse.EqualFold(val[:5], dataSchemeBytes) {
val = minify.DataURI(m, val)
}
}
if _, err := w.Write(spaceBytes); err != nil {
return err
}
if _, err := w.Write(attr.Text); err != nil {
return err
}
if len(val) > 0 && attr.Traits&booleanAttr == 0 {
if _, err := w.Write(isBytes); err != nil {
return err
}
// no quotes if possible, else prefer single or double depending on which occurs more often in value
val = html.EscapeAttrVal(&attrByteBuffer, attr.AttrVal, val)
if _, err := w.Write(val); err != nil {
return err
}
}
}
}
if _, err := w.Write(gtBytes); err != nil {
return err
}
}
}
}