hugo html 代码
文件路径：/tpl/internal/go_templates/htmltemplate/html.go
/ Copyright 2011 The Go Authors. All rights reserved.
/ Use of this source code is governed by a BSD-style
/ license that can be found in the LICENSE file.
package template
import (
"bytes"
"fmt"
"strings"
"unicode/utf8"
)
/ htmlNospaceEscaper escapes for inclusion in unquoted attribute values.
func htmlNospaceEscaper(args ...any) string {
s, t := stringify(args...)
if t == contentTypeHTML {
return htmlReplacer(stripTags(s), htmlNospaceNormReplacementTable, false)
}
return htmlReplacer(s, htmlNospaceReplacementTable, false)
}
/ attrEscaper escapes for inclusion in quoted attribute values.
func attrEscaper(args ...any) string {
s, t := stringify(args...)
if t == contentTypeHTML {
return htmlReplacer(stripTags(s), htmlNormReplacementTable, true)
}
return htmlReplacer(s, htmlReplacementTable, true)
}
/ rcdataEscaper escapes for inclusion in an RCDATA element body.
func rcdataEscaper(args ...any) string {
s, t := stringify(args...)
if t == contentTypeHTML {
return htmlReplacer(s, htmlNormReplacementTable, true)
}
return htmlReplacer(s, htmlReplacementTable, true)
}
/ htmlEscaper escapes for inclusion in HTML text.
func htmlEscaper(args ...any) string {
s, t := stringify(args...)
if t == contentTypeHTML {
return s
}
return htmlReplacer(s, htmlReplacementTable, true)
}
/ htmlReplacementTable contains the runes that need to be escaped
/ inside a quoted attribute value or in a text node.
var htmlReplacementTable = []string{
/ https://www.w3.org/TR/html5/syntax.html#attribute-value-(unquoted)-state
/ U+0000 NULL Parse error. Append a U+FFFD REPLACEMENT
/ CHARACTER character to the current attribute's value.
/ "
/ and similarly
/ https://www.w3.org/TR/html5/syntax.html#before-attribute-value-state
0: "\uFFFD",
'"': """,
'&': "&",
'\'': "'",
'+': "+",
'<': "<",
'>': ">",
}
/ htmlNormReplacementTable is like htmlReplacementTable but without '&' to
/ avoid over-encoding existing entities.
var htmlNormReplacementTable = []string{
0: "\uFFFD",
'"': """,
'\'': "'",
'+': "+",
'<': "<",
'>': ">",
}
/ htmlNospaceReplacementTable contains the runes that need to be escaped
/ inside an unquoted attribute value.
/ The set of runes escaped is the union of the HTML specials and
/ those determined by running the JS below in browsers:
/ <div id=d></div>
/ <script>(function () {
/ var a = [], d = document.getElementById("d"), i, c, s;
/ for (i = 0; i < 0x10000; ++i) {
/ c = String.fromCharCode(i);
/ d.innerHTML = "<span title=" + c + "lt" + c + "></span>"
/ s = d.getElementsByTagName("SPAN")[0];
/ if (!s || s.title !== c + "lt" + c) { a.push(i.toString(16)); }
/ }
/ document.write(a.join(", "));
/ })()</script>
var htmlNospaceReplacementTable = []string{
0: "�",
'\t': "	",
'\n': " ",
'\v': "",
'\f': "",
'\r': " ",
' ': " ",
'"': """,
'&': "&",
'\'': "'",
'+': "+",
'<': "<",
'=': "=",
'>': ">",
/ A parse error in the attribute value (unquoted) and
/ before attribute value states.
/ Treated as a quoting character by IE.
'`': "`",
}
/ htmlNospaceNormReplacementTable is like htmlNospaceReplacementTable but
/ without '&' to avoid over-encoding existing entities.
var htmlNospaceNormReplacementTable = []string{
0: "�",
'\t': "	",
'\n': " ",
'\v': "",
'\f': "",
'\r': " ",
' ': " ",
'"': """,
'\'': "'",
'+': "+",
'<': "<",
'=': "=",
'>': ">",
/ A parse error in the attribute value (unquoted) and
/ before attribute value states.
/ Treated as a quoting character by IE.
'`': "`",
}
/ htmlReplacer returns s with runes replaced according to replacementTable
/ and when badRunes is true, certain bad runes are allowed through unescaped.
func htmlReplacer(s string, replacementTable []string, badRunes bool) string {
written, b := 0, new(strings.Builder)
r, w := rune(0), 0
for i := 0; i < len(s); i += w {
/ Cannot use 'for range s' because we need to preserve the width
/ of the runes in the input. If we see a decoding error, the input
/ width will not be utf8.Runelen(r) and we will overrun the buffer.
r, w = utf8.DecodeRuneInString(s[i:])
if int(r) < len(replacementTable) {
if repl := replacementTable[r]; len(repl) != 0 {
if written == 0 {
b.Grow(len(s))
}
b.WriteString(s[written:i])
b.WriteString(repl)
written = i + w
}
} else if badRunes {
/ No-op.
/ IE does not allow these ranges in unquoted attrs.
} else if 0xfdd0 <= r && r <= 0xfdef || 0xfff0 <= r && r <= 0xffff {
if written == 0 {
b.Grow(len(s))
}
fmt.Fprintf(b, "%s&#x%x;", s[written:i], r)
written = i + w
}
}
if written == 0 {
return s
}
b.WriteString(s[written:])
return b.String()
}
/ stripTags takes a snippet of HTML and returns only the text content.
/ For example, `<b>¡Hi!</b> <script>...</script>` -> `¡Hi! `.
func stripTags(html string) string {
var b bytes.Buffer
s, c, i, allText := []byte(html), context{}, 0, true
/ Using the transition funcs helps us avoid mangling
/ `<div title="1>2">` or `I <3 Ponies!`.
for i != len(s) {
if c.delim == delimNone {
st := c.state
/ Use RCDATA instead of parsing into JS or CSS styles.
if c.element != elementNone && !isInTag(st) {
st = stateRCDATA
}
d, nread := transitionFunc[st](c, s[i:])
i1 := i + nread
if c.state == stateText || c.state == stateRCDATA {
/ Emit text up to the start of the tag or comment.
j := i1
if d.state != c.state {
for j1 := j - 1; j1 >= i; j1-- {
if s[j1] == '<' {
j = j1
break
}
}
}
b.Write(s[i:j])
} else {
allText = false
}
c, i = d, i1
continue
}
i1 := i + bytes.IndexAny(s[i:], delimEnds[c.delim])
if i1 < i {
break
}
if c.delim != delimSpaceOrTagEnd {
/ Consume any quote.
i1++
}
c, i = context{state: stateTag, element: c.element}, i1
}
if allText {
return html
} else if c.state == stateText || c.state == stateRCDATA {
b.Write(s[i:])
}
return b.String()
}
/ htmlNameFilter accepts valid parts of an HTML attribute or tag name or
/ a known-safe HTML attribute.
func htmlNameFilter(args ...any) string {
s, t := stringify(args...)
if t == contentTypeHTMLAttr {
return s
}
if len(s) == 0 {
/ Avoid violation of structure preservation.
/ <input checked {{.K}}={{.V}}>.
/ Without this, if .K is empty then .V is the value of
/ checked, but otherwise .V is the value of the attribute
/ named .K.
return filterFailsafe
}
s = strings.ToLower(s)
if t := attrType(s); t != contentTypePlain {
/ TODO: Split attr and element name part filters so we can recognize known attributes.
return filterFailsafe
}
for _, r := range s {
switch {
case '0' <= r && r <= '9':
case 'a' <= r && r <= 'z':
default:
return filterFailsafe
}
}
return s
}
/ commentEscaper returns the empty string regardless of input.
/ Comment content does not correspond to any parsed structure or
/ human-readable content, so the simplest and most secure policy is to drop
/ content interpolated into comments.
/ This approach is equally valid whether or not static comment content is
/ removed from the template.
func commentEscaper(args ...any) string {
return ""
}