mirror of
https://github.com/Luzifer/vault-otp-ui.git
synced 2024-11-13 02:22:46 +00:00
424 lines
9.5 KiB
Go
424 lines
9.5 KiB
Go
// Package html is an HTML5 lexer following the specifications at http://www.w3.org/TR/html5/syntax.html.
|
|
package html
|
|
|
|
import (
|
|
"io"
|
|
"strconv"
|
|
|
|
"github.com/tdewolff/buffer"
|
|
"github.com/tdewolff/parse"
|
|
)
|
|
|
|
////////////////////////////////////////////////////////////////
|
|
|
|
// TokenType determines the type of token, eg. a number or a semicolon.
|
|
type TokenType uint32
|
|
|
|
// TokenType values.
|
|
const (
|
|
ErrorToken TokenType = iota // extra token when errors occur
|
|
CommentToken
|
|
DoctypeToken
|
|
StartTagToken
|
|
StartTagCloseToken
|
|
StartTagVoidToken
|
|
EndTagToken
|
|
AttributeToken
|
|
TextToken
|
|
)
|
|
|
|
// String returns the string representation of a TokenType.
|
|
func (tt TokenType) String() string {
|
|
switch tt {
|
|
case ErrorToken:
|
|
return "Error"
|
|
case CommentToken:
|
|
return "Comment"
|
|
case DoctypeToken:
|
|
return "Doctype"
|
|
case StartTagToken:
|
|
return "StartTag"
|
|
case StartTagCloseToken:
|
|
return "StartTagClose"
|
|
case StartTagVoidToken:
|
|
return "StartTagVoid"
|
|
case EndTagToken:
|
|
return "EndTag"
|
|
case AttributeToken:
|
|
return "Attribute"
|
|
case TextToken:
|
|
return "Text"
|
|
}
|
|
return "Invalid(" + strconv.Itoa(int(tt)) + ")"
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////
|
|
|
|
// Lexer is the state for the lexer.
|
|
type Lexer struct {
|
|
r *buffer.Lexer
|
|
|
|
rawTag Hash
|
|
inTag bool
|
|
|
|
text []byte
|
|
attrVal []byte
|
|
}
|
|
|
|
// NewLexer returns a new Lexer for a given io.Reader.
|
|
func NewLexer(r io.Reader) *Lexer {
|
|
return &Lexer{
|
|
r: buffer.NewLexer(r),
|
|
}
|
|
}
|
|
|
|
// Err returns the error encountered during lexing, this is often io.EOF but also other errors can be returned.
|
|
func (l *Lexer) Err() error {
|
|
return l.r.Err()
|
|
}
|
|
|
|
// Free frees up bytes of length n from previously shifted tokens.
|
|
func (l *Lexer) Free(n int) {
|
|
l.r.Free(n)
|
|
}
|
|
|
|
// Next returns the next Token. It returns ErrorToken when an error was encountered. Using Err() one can retrieve the error message.
|
|
func (l *Lexer) Next() (TokenType, []byte) {
|
|
l.text = nil
|
|
var c byte
|
|
if l.inTag {
|
|
l.attrVal = nil
|
|
for { // before attribute name state
|
|
if c = l.r.Peek(0); c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f' {
|
|
l.r.Move(1)
|
|
continue
|
|
}
|
|
break
|
|
}
|
|
if c == 0 {
|
|
return ErrorToken, nil
|
|
} else if c != '>' && (c != '/' || l.r.Peek(1) != '>') {
|
|
return AttributeToken, l.shiftAttribute()
|
|
}
|
|
start := l.r.Pos()
|
|
l.inTag = false
|
|
if c == '/' {
|
|
l.r.Move(2)
|
|
l.text = l.r.Lexeme()[start:]
|
|
return StartTagVoidToken, l.r.Shift()
|
|
}
|
|
l.r.Move(1)
|
|
l.text = l.r.Lexeme()[start:]
|
|
return StartTagCloseToken, l.r.Shift()
|
|
}
|
|
|
|
if l.rawTag != 0 {
|
|
if rawText := l.shiftRawText(); len(rawText) > 0 {
|
|
l.rawTag = 0
|
|
return TextToken, rawText
|
|
}
|
|
l.rawTag = 0
|
|
}
|
|
|
|
for {
|
|
c = l.r.Peek(0)
|
|
if c == '<' {
|
|
c = l.r.Peek(1)
|
|
if l.r.Pos() > 0 {
|
|
if c == '/' && l.r.Peek(2) != 0 || 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z' || c == '!' || c == '?' {
|
|
return TextToken, l.r.Shift()
|
|
}
|
|
} else if c == '/' && l.r.Peek(2) != 0 {
|
|
l.r.Move(2)
|
|
if c = l.r.Peek(0); c != '>' && !('a' <= c && c <= 'z' || 'A' <= c && c <= 'Z') {
|
|
return CommentToken, l.shiftBogusComment()
|
|
}
|
|
return EndTagToken, l.shiftEndTag()
|
|
} else if 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z' {
|
|
l.r.Move(1)
|
|
l.inTag = true
|
|
return StartTagToken, l.shiftStartTag()
|
|
} else if c == '!' {
|
|
l.r.Move(2)
|
|
return l.readMarkup()
|
|
} else if c == '?' {
|
|
l.r.Move(1)
|
|
return CommentToken, l.shiftBogusComment()
|
|
}
|
|
} else if c == 0 {
|
|
if l.r.Pos() > 0 {
|
|
return TextToken, l.r.Shift()
|
|
}
|
|
return ErrorToken, nil
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
}
|
|
|
|
// Text returns the textual representation of a token. This excludes delimiters and additional leading/trailing characters.
|
|
func (l *Lexer) Text() []byte {
|
|
return l.text
|
|
}
|
|
|
|
// AttrVal returns the attribute value when an AttributeToken was returned from Next.
|
|
func (l *Lexer) AttrVal() []byte {
|
|
return l.attrVal
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////
|
|
|
|
// The following functions follow the specifications at http://www.w3.org/html/wg/drafts/html/master/syntax.html
|
|
|
|
func (l *Lexer) shiftRawText() []byte {
|
|
if l.rawTag == Plaintext {
|
|
for {
|
|
if l.r.Peek(0) == 0 {
|
|
return l.r.Shift()
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
} else { // RCDATA, RAWTEXT and SCRIPT
|
|
for {
|
|
c := l.r.Peek(0)
|
|
if c == '<' {
|
|
if l.r.Peek(1) == '/' {
|
|
mark := l.r.Pos()
|
|
l.r.Move(2)
|
|
for {
|
|
if c = l.r.Peek(0); !('a' <= c && c <= 'z' || 'A' <= c && c <= 'Z') {
|
|
break
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
if h := ToHash(parse.ToLower(parse.Copy(l.r.Lexeme()[mark+2:]))); h == l.rawTag { // copy so that ToLower doesn't change the case of the underlying slice
|
|
l.r.Rewind(mark)
|
|
return l.r.Shift()
|
|
}
|
|
} else if l.rawTag == Script && l.r.Peek(1) == '!' && l.r.Peek(2) == '-' && l.r.Peek(3) == '-' {
|
|
l.r.Move(4)
|
|
inScript := false
|
|
for {
|
|
c := l.r.Peek(0)
|
|
if c == '-' && l.r.Peek(1) == '-' && l.r.Peek(2) == '>' {
|
|
l.r.Move(3)
|
|
break
|
|
} else if c == '<' {
|
|
isEnd := l.r.Peek(1) == '/'
|
|
if isEnd {
|
|
l.r.Move(2)
|
|
} else {
|
|
l.r.Move(1)
|
|
}
|
|
mark := l.r.Pos()
|
|
for {
|
|
if c = l.r.Peek(0); !('a' <= c && c <= 'z' || 'A' <= c && c <= 'Z') {
|
|
break
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
if h := ToHash(parse.ToLower(parse.Copy(l.r.Lexeme()[mark:]))); h == Script { // copy so that ToLower doesn't change the case of the underlying slice
|
|
if !isEnd {
|
|
inScript = true
|
|
} else {
|
|
if !inScript {
|
|
l.r.Rewind(mark - 2)
|
|
return l.r.Shift()
|
|
}
|
|
inScript = false
|
|
}
|
|
}
|
|
} else if c == 0 {
|
|
return l.r.Shift()
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
} else {
|
|
l.r.Move(1)
|
|
}
|
|
} else if c == 0 {
|
|
return l.r.Shift()
|
|
} else {
|
|
l.r.Move(1)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
func (l *Lexer) readMarkup() (TokenType, []byte) {
|
|
if l.at('-', '-') {
|
|
l.r.Move(2)
|
|
for {
|
|
if l.r.Peek(0) == 0 {
|
|
return CommentToken, l.r.Shift()
|
|
} else if l.at('-', '-', '>') {
|
|
l.text = l.r.Lexeme()[4:]
|
|
l.r.Move(3)
|
|
return CommentToken, l.r.Shift()
|
|
} else if l.at('-', '-', '!', '>') {
|
|
l.text = l.r.Lexeme()[4:]
|
|
l.r.Move(4)
|
|
return CommentToken, l.r.Shift()
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
} else if l.at('[', 'C', 'D', 'A', 'T', 'A', '[') {
|
|
l.r.Move(7)
|
|
for {
|
|
if l.r.Peek(0) == 0 {
|
|
return TextToken, l.r.Shift()
|
|
} else if l.at(']', ']', '>') {
|
|
l.r.Move(3)
|
|
return TextToken, l.r.Shift()
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
} else {
|
|
if l.atCaseInsensitive('d', 'o', 'c', 't', 'y', 'p', 'e') {
|
|
l.r.Move(7)
|
|
if l.r.Peek(0) == ' ' {
|
|
l.r.Move(1)
|
|
}
|
|
for {
|
|
if c := l.r.Peek(0); c == '>' || c == 0 {
|
|
l.text = l.r.Lexeme()[9:]
|
|
l.r.Move(1)
|
|
return DoctypeToken, l.r.Shift()
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
}
|
|
}
|
|
return CommentToken, l.shiftBogusComment()
|
|
}
|
|
|
|
func (l *Lexer) shiftBogusComment() []byte {
|
|
for {
|
|
c := l.r.Peek(0)
|
|
if c == '>' {
|
|
l.text = l.r.Lexeme()[2:]
|
|
l.r.Move(1)
|
|
return l.r.Shift()
|
|
} else if c == 0 {
|
|
l.text = l.r.Lexeme()[2:]
|
|
return l.r.Shift()
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
}
|
|
|
|
func (l *Lexer) shiftStartTag() []byte {
|
|
for {
|
|
if c := l.r.Peek(0); c == ' ' || c == '>' || c == '/' && l.r.Peek(1) == '>' || c == '\t' || c == '\n' || c == '\r' || c == '\f' || c == 0 {
|
|
break
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
l.text = parse.ToLower(l.r.Lexeme()[1:])
|
|
if h := ToHash(l.text); h == Textarea || h == Title || h == Style || h == Xmp || h == Iframe || h == Script || h == Plaintext || h == Svg || h == Math {
|
|
l.rawTag = h
|
|
}
|
|
return l.r.Shift()
|
|
}
|
|
|
|
func (l *Lexer) shiftAttribute() []byte {
|
|
nameStart := l.r.Pos()
|
|
var c byte
|
|
for { // attribute name state
|
|
if c = l.r.Peek(0); c == ' ' || c == '=' || c == '>' || c == '/' && l.r.Peek(1) == '>' || c == '\t' || c == '\n' || c == '\r' || c == '\f' || c == 0 {
|
|
break
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
nameEnd := l.r.Pos()
|
|
for { // after attribute name state
|
|
if c = l.r.Peek(0); c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f' {
|
|
l.r.Move(1)
|
|
continue
|
|
}
|
|
break
|
|
}
|
|
if c == '=' {
|
|
l.r.Move(1)
|
|
for { // before attribute value state
|
|
if c = l.r.Peek(0); c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f' {
|
|
l.r.Move(1)
|
|
continue
|
|
}
|
|
break
|
|
}
|
|
attrPos := l.r.Pos()
|
|
delim := c
|
|
if delim == '"' || delim == '\'' { // attribute value single- and double-quoted state
|
|
l.r.Move(1)
|
|
for {
|
|
c := l.r.Peek(0)
|
|
if c == delim {
|
|
l.r.Move(1)
|
|
break
|
|
} else if c == 0 {
|
|
break
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
} else { // attribute value unquoted state
|
|
for {
|
|
if c := l.r.Peek(0); c == ' ' || c == '>' || c == '\t' || c == '\n' || c == '\r' || c == '\f' || c == 0 {
|
|
break
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
}
|
|
l.attrVal = l.r.Lexeme()[attrPos:]
|
|
} else {
|
|
l.r.Rewind(nameEnd)
|
|
l.attrVal = nil
|
|
}
|
|
l.text = parse.ToLower(l.r.Lexeme()[nameStart:nameEnd])
|
|
return l.r.Shift()
|
|
}
|
|
|
|
func (l *Lexer) shiftEndTag() []byte {
|
|
for {
|
|
c := l.r.Peek(0)
|
|
if c == '>' {
|
|
l.text = l.r.Lexeme()[2:]
|
|
l.r.Move(1)
|
|
break
|
|
} else if c == 0 {
|
|
l.text = l.r.Lexeme()[2:]
|
|
break
|
|
}
|
|
l.r.Move(1)
|
|
}
|
|
|
|
end := len(l.text)
|
|
for end > 0 {
|
|
if c := l.text[end-1]; c == ' ' || c == '\t' || c == '\n' || c == '\r' {
|
|
end--
|
|
continue
|
|
}
|
|
break
|
|
}
|
|
l.text = l.text[:end]
|
|
return parse.ToLower(l.r.Shift())
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////
|
|
|
|
func (l *Lexer) at(b ...byte) bool {
|
|
for i, c := range b {
|
|
if l.r.Peek(i) != c {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
func (l *Lexer) atCaseInsensitive(b ...byte) bool {
|
|
for i, c := range b {
|
|
if l.r.Peek(i) != c && (l.r.Peek(i)+('a'-'A')) != c {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|