miniflux/vendor/github.com/tdewolff/parse/html/util.go
Frédéric Guillot 8ffb773f43 First commit
2017-11-19 22:01:46 -08:00

129 lines
3.7 KiB
Go

package html // import "github.com/tdewolff/parse/html"
import "github.com/tdewolff/parse"
var (
singleQuoteEntityBytes = []byte("'")
doubleQuoteEntityBytes = []byte(""")
)
var charTable = [256]bool{
// ASCII
false, false, false, false, false, false, false, false,
false, true, true, true, true, true, false, false, // tab, new line, vertical tab, form feed, carriage return
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
true, false, true, false, false, false, true, true, // space, ", &, '
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, true, true, true, false, // <, =, >
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
true, false, false, false, false, false, false, false, // `
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
// non-ASCII
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false,
}
// EscapeAttrVal returns the escaped attribute value bytes without quotes.
func EscapeAttrVal(buf *[]byte, orig, b []byte) []byte {
singles := 0
doubles := 0
unquoted := true
entities := false
for i, c := range b {
if charTable[c] {
if c == '&' {
entities = true
if quote, n := parse.QuoteEntity(b[i:]); n > 0 {
if quote == '"' {
unquoted = false
doubles++
} else {
unquoted = false
singles++
}
}
} else {
unquoted = false
if c == '"' {
doubles++
} else if c == '\'' {
singles++
}
}
}
}
if unquoted {
return b
} else if !entities && len(orig) == len(b)+2 && (singles == 0 && orig[0] == '\'' || doubles == 0 && orig[0] == '"') {
return orig
}
n := len(b) + 2
var quote byte
var escapedQuote []byte
if doubles > singles {
n += singles * 4
quote = '\''
escapedQuote = singleQuoteEntityBytes
} else {
n += doubles * 4
quote = '"'
escapedQuote = doubleQuoteEntityBytes
}
if n > cap(*buf) {
*buf = make([]byte, 0, n) // maximum size, not actual size
}
t := (*buf)[:n] // maximum size, not actual size
t[0] = quote
j := 1
start := 0
for i, c := range b {
if c == '&' {
if entityQuote, n := parse.QuoteEntity(b[i:]); n > 0 {
j += copy(t[j:], b[start:i])
if entityQuote != quote {
t[j] = entityQuote
j++
} else {
j += copy(t[j:], escapedQuote)
}
start = i + n
}
} else if c == quote {
j += copy(t[j:], b[start:i])
j += copy(t[j:], escapedQuote)
start = i + 1
}
}
j += copy(t[j:], b[start:])
t[j] = quote
return t[:j+1]
}