mirror of
https://github.com/miniflux/v2.git
synced 2024-09-06 03:19:20 +02:00
464 lines
16 KiB
Go
464 lines
16 KiB
Go
// 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]"))) {
|
|
// [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 ")) { // 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
|
|
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 {
|
|
content.AttrVal = minify.ContentType(content.AttrVal)
|
|
if charset := attrs[2]; charset == nil && parse.EqualFold(httpEquiv.AttrVal, []byte("content-type")) && 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")) {
|
|
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")) {
|
|
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.ContentType(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
|
|
}
|
|
}
|
|
}
|
|
}
|