From 14bb08c1df8db9ec6c8a05520d4eee67971235d9 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Thu, 27 Sep 2018 20:03:23 +0200 Subject: mod tidy --- vendor/golang.org/x/net/html/token.go | 1219 --------------------------------- 1 file changed, 1219 deletions(-) delete mode 100644 vendor/golang.org/x/net/html/token.go (limited to 'vendor/golang.org/x/net/html/token.go') diff --git a/vendor/golang.org/x/net/html/token.go b/vendor/golang.org/x/net/html/token.go deleted file mode 100644 index e3c01d7..0000000 --- a/vendor/golang.org/x/net/html/token.go +++ /dev/null @@ -1,1219 +0,0 @@ -// Copyright 2010 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 html - -import ( - "bytes" - "errors" - "io" - "strconv" - "strings" - - "golang.org/x/net/html/atom" -) - -// A TokenType is the type of a Token. -type TokenType uint32 - -const ( - // ErrorToken means that an error occurred during tokenization. - ErrorToken TokenType = iota - // TextToken means a text node. - TextToken - // A StartTagToken looks like . - StartTagToken - // An EndTagToken looks like . - EndTagToken - // A SelfClosingTagToken tag looks like
. - SelfClosingTagToken - // A CommentToken looks like . - CommentToken - // A DoctypeToken looks like - DoctypeToken -) - -// ErrBufferExceeded means that the buffering limit was exceeded. -var ErrBufferExceeded = errors.New("max buffer exceeded") - -// String returns a string representation of the TokenType. -func (t TokenType) String() string { - switch t { - case ErrorToken: - return "Error" - case TextToken: - return "Text" - case StartTagToken: - return "StartTag" - case EndTagToken: - return "EndTag" - case SelfClosingTagToken: - return "SelfClosingTag" - case CommentToken: - return "Comment" - case DoctypeToken: - return "Doctype" - } - return "Invalid(" + strconv.Itoa(int(t)) + ")" -} - -// An Attribute is an attribute namespace-key-value triple. Namespace is -// non-empty for foreign attributes like xlink, Key is alphabetic (and hence -// does not contain escapable characters like '&', '<' or '>'), and Val is -// unescaped (it looks like "a" - case EndTagToken: - return "" - case SelfClosingTagToken: - return "<" + t.tagString() + "/>" - case CommentToken: - return "" - case DoctypeToken: - return "" - } - return "Invalid(" + strconv.Itoa(int(t.Type)) + ")" -} - -// span is a range of bytes in a Tokenizer's buffer. The start is inclusive, -// the end is exclusive. -type span struct { - start, end int -} - -// A Tokenizer returns a stream of HTML Tokens. -type Tokenizer struct { - // r is the source of the HTML text. - r io.Reader - // tt is the TokenType of the current token. - tt TokenType - // err is the first error encountered during tokenization. It is possible - // for tt != Error && err != nil to hold: this means that Next returned a - // valid token but the subsequent Next call will return an error token. - // For example, if the HTML text input was just "plain", then the first - // Next call would set z.err to io.EOF but return a TextToken, and all - // subsequent Next calls would return an ErrorToken. - // err is never reset. Once it becomes non-nil, it stays non-nil. - err error - // readErr is the error returned by the io.Reader r. It is separate from - // err because it is valid for an io.Reader to return (n int, err1 error) - // such that n > 0 && err1 != nil, and callers should always process the - // n > 0 bytes before considering the error err1. - readErr error - // buf[raw.start:raw.end] holds the raw bytes of the current token. - // buf[raw.end:] is buffered input that will yield future tokens. - raw span - buf []byte - // maxBuf limits the data buffered in buf. A value of 0 means unlimited. - maxBuf int - // buf[data.start:data.end] holds the raw bytes of the current token's data: - // a text token's text, a tag token's tag name, etc. - data span - // pendingAttr is the attribute key and value currently being tokenized. - // When complete, pendingAttr is pushed onto attr. nAttrReturned is - // incremented on each call to TagAttr. - pendingAttr [2]span - attr [][2]span - nAttrReturned int - // rawTag is the "script" in "" that closes the next token. If - // non-empty, the subsequent call to Next will return a raw or RCDATA text - // token: one that treats "

" as text instead of an element. - // rawTag's contents are lower-cased. - rawTag string - // textIsRaw is whether the current text token's data is not escaped. - textIsRaw bool - // convertNUL is whether NUL bytes in the current token's data should - // be converted into \ufffd replacement characters. - convertNUL bool - // allowCDATA is whether CDATA sections are allowed in the current context. - allowCDATA bool -} - -// AllowCDATA sets whether or not the tokenizer recognizes as -// the text "foo". The default value is false, which means to recognize it as -// a bogus comment "" instead. -// -// Strictly speaking, an HTML5 compliant tokenizer should allow CDATA if and -// only if tokenizing foreign content, such as MathML and SVG. However, -// tracking foreign-contentness is difficult to do purely in the tokenizer, -// as opposed to the parser, due to HTML integration points: an element -// can contain a that is foreign-to-SVG but not foreign-to- -// HTML. For strict compliance with the HTML5 tokenization algorithm, it is the -// responsibility of the user of a tokenizer to call AllowCDATA as appropriate. -// In practice, if using the tokenizer without caring whether MathML or SVG -// CDATA is text or comments, such as tokenizing HTML to find all the anchor -// text, it is acceptable to ignore this responsibility. -func (z *Tokenizer) AllowCDATA(allowCDATA bool) { - z.allowCDATA = allowCDATA -} - -// NextIsNotRawText instructs the tokenizer that the next token should not be -// considered as 'raw text'. Some elements, such as script and title elements, -// normally require the next token after the opening tag to be 'raw text' that -// has no child elements. For example, tokenizing "a<b>c</b>d" -// yields a start tag token for "", a text token for "a<b>c</b>d", and -// an end tag token for "". There are no distinct start tag or end tag -// tokens for the "" and "". -// -// This tokenizer implementation will generally look for raw text at the right -// times. Strictly speaking, an HTML5 compliant tokenizer should not look for -// raw text if in foreign content: generally needs raw text, but a -// <title> inside an <svg> does not. Another example is that a <textarea> -// generally needs raw text, but a <textarea> is not allowed as an immediate -// child of a <select>; in normal parsing, a <textarea> implies </select>, but -// one cannot close the implicit element when parsing a <select>'s InnerHTML. -// Similarly to AllowCDATA, tracking the correct moment to override raw-text- -// ness is difficult to do purely in the tokenizer, as opposed to the parser. -// For strict compliance with the HTML5 tokenization algorithm, it is the -// responsibility of the user of a tokenizer to call NextIsNotRawText as -// appropriate. In practice, like AllowCDATA, it is acceptable to ignore this -// responsibility for basic usage. -// -// Note that this 'raw text' concept is different from the one offered by the -// Tokenizer.Raw method. -func (z *Tokenizer) NextIsNotRawText() { - z.rawTag = "" -} - -// Err returns the error associated with the most recent ErrorToken token. -// This is typically io.EOF, meaning the end of tokenization. -func (z *Tokenizer) Err() error { - if z.tt != ErrorToken { - return nil - } - return z.err -} - -// readByte returns the next byte from the input stream, doing a buffered read -// from z.r into z.buf if necessary. z.buf[z.raw.start:z.raw.end] remains a contiguous byte -// slice that holds all the bytes read so far for the current token. -// It sets z.err if the underlying reader returns an error. -// Pre-condition: z.err == nil. -func (z *Tokenizer) readByte() byte { - if z.raw.end >= len(z.buf) { - // Our buffer is exhausted and we have to read from z.r. Check if the - // previous read resulted in an error. - if z.readErr != nil { - z.err = z.readErr - return 0 - } - // We copy z.buf[z.raw.start:z.raw.end] to the beginning of z.buf. If the length - // z.raw.end - z.raw.start is more than half the capacity of z.buf, then we - // allocate a new buffer before the copy. - c := cap(z.buf) - d := z.raw.end - z.raw.start - var buf1 []byte - if 2*d > c { - buf1 = make([]byte, d, 2*c) - } else { - buf1 = z.buf[:d] - } - copy(buf1, z.buf[z.raw.start:z.raw.end]) - if x := z.raw.start; x != 0 { - // Adjust the data/attr spans to refer to the same contents after the copy. - z.data.start -= x - z.data.end -= x - z.pendingAttr[0].start -= x - z.pendingAttr[0].end -= x - z.pendingAttr[1].start -= x - z.pendingAttr[1].end -= x - for i := range z.attr { - z.attr[i][0].start -= x - z.attr[i][0].end -= x - z.attr[i][1].start -= x - z.attr[i][1].end -= x - } - } - z.raw.start, z.raw.end, z.buf = 0, d, buf1[:d] - // Now that we have copied the live bytes to the start of the buffer, - // we read from z.r into the remainder. - var n int - n, z.readErr = readAtLeastOneByte(z.r, buf1[d:cap(buf1)]) - if n == 0 { - z.err = z.readErr - return 0 - } - z.buf = buf1[:d+n] - } - x := z.buf[z.raw.end] - z.raw.end++ - if z.maxBuf > 0 && z.raw.end-z.raw.start >= z.maxBuf { - z.err = ErrBufferExceeded - return 0 - } - return x -} - -// Buffered returns a slice containing data buffered but not yet tokenized. -func (z *Tokenizer) Buffered() []byte { - return z.buf[z.raw.end:] -} - -// readAtLeastOneByte wraps an io.Reader so that reading cannot return (0, nil). -// It returns io.ErrNoProgress if the underlying r.Read method returns (0, nil) -// too many times in succession. -func readAtLeastOneByte(r io.Reader, b []byte) (int, error) { - for i := 0; i < 100; i++ { - n, err := r.Read(b) - if n != 0 || err != nil { - return n, err - } - } - return 0, io.ErrNoProgress -} - -// skipWhiteSpace skips past any white space. -func (z *Tokenizer) skipWhiteSpace() { - if z.err != nil { - return - } - for { - c := z.readByte() - if z.err != nil { - return - } - switch c { - case ' ', '\n', '\r', '\t', '\f': - // No-op. - default: - z.raw.end-- - return - } - } -} - -// readRawOrRCDATA reads until the next "</foo>", where "foo" is z.rawTag and -// is typically something like "script" or "textarea". -func (z *Tokenizer) readRawOrRCDATA() { - if z.rawTag == "script" { - z.readScript() - z.textIsRaw = true - z.rawTag = "" - return - } -loop: - for { - c := z.readByte() - if z.err != nil { - break loop - } - if c != '<' { - continue loop - } - c = z.readByte() - if z.err != nil { - break loop - } - if c != '/' { - continue loop - } - if z.readRawEndTag() || z.err != nil { - break loop - } - } - z.data.end = z.raw.end - // A textarea's or title's RCDATA can contain escaped entities. - z.textIsRaw = z.rawTag != "textarea" && z.rawTag != "title" - z.rawTag = "" -} - -// readRawEndTag attempts to read a tag like "</foo>", where "foo" is z.rawTag. -// If it succeeds, it backs up the input position to reconsume the tag and -// returns true. Otherwise it returns false. The opening "</" has already been -// consumed. -func (z *Tokenizer) readRawEndTag() bool { - for i := 0; i < len(z.rawTag); i++ { - c := z.readByte() - if z.err != nil { - return false - } - if c != z.rawTag[i] && c != z.rawTag[i]-('a'-'A') { - z.raw.end-- - return false - } - } - c := z.readByte() - if z.err != nil { - return false - } - switch c { - case ' ', '\n', '\r', '\t', '\f', '/', '>': - // The 3 is 2 for the leading "</" plus 1 for the trailing character c. - z.raw.end -= 3 + len(z.rawTag) - return true - } - z.raw.end-- - return false -} - -// readScript reads until the next </script> tag, following the byzantine -// rules for escaping/hiding the closing tag. -func (z *Tokenizer) readScript() { - defer func() { - z.data.end = z.raw.end - }() - var c byte - -scriptData: - c = z.readByte() - if z.err != nil { - return - } - if c == '<' { - goto scriptDataLessThanSign - } - goto scriptData - -scriptDataLessThanSign: - c = z.readByte() - if z.err != nil { - return - } - switch c { - case '/': - goto scriptDataEndTagOpen - case '!': - goto scriptDataEscapeStart - } - z.raw.end-- - goto scriptData - -scriptDataEndTagOpen: - if z.readRawEndTag() || z.err != nil { - return - } - goto scriptData - -scriptDataEscapeStart: - c = z.readByte() - if z.err != nil { - return - } - if c == '-' { - goto scriptDataEscapeStartDash - } - z.raw.end-- - goto scriptData - -scriptDataEscapeStartDash: - c = z.readByte() - if z.err != nil { - return - } - if c == '-' { - goto scriptDataEscapedDashDash - } - z.raw.end-- - goto scriptData - -scriptDataEscaped: - c = z.readByte() - if z.err != nil { - return - } - switch c { - case '-': - goto scriptDataEscapedDash - case '<': - goto scriptDataEscapedLessThanSign - } - goto scriptDataEscaped - -scriptDataEscapedDash: - c = z.readByte() - if z.err != nil { - return - } - switch c { - case '-': - goto scriptDataEscapedDashDash - case '<': - goto scriptDataEscapedLessThanSign - } - goto scriptDataEscaped - -scriptDataEscapedDashDash: - c = z.readByte() - if z.err != nil { - return - } - switch c { - case '-': - goto scriptDataEscapedDashDash - case '<': - goto scriptDataEscapedLessThanSign - case '>': - goto scriptData - } - goto scriptDataEscaped - -scriptDataEscapedLessThanSign: - c = z.readByte() - if z.err != nil { - return - } - if c == '/' { - goto scriptDataEscapedEndTagOpen - } - if 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z' { - goto scriptDataDoubleEscapeStart - } - z.raw.end-- - goto scriptData - -scriptDataEscapedEndTagOpen: - if z.readRawEndTag() || z.err != nil { - return - } - goto scriptDataEscaped - -scriptDataDoubleEscapeStart: - z.raw.end-- - for i := 0; i < len("script"); i++ { - c = z.readByte() - if z.err != nil { - return - } - if c != "script"[i] && c != "SCRIPT"[i] { - z.raw.end-- - goto scriptDataEscaped - } - } - c = z.readByte() - if z.err != nil { - return - } - switch c { - case ' ', '\n', '\r', '\t', '\f', '/', '>': - goto scriptDataDoubleEscaped - } - z.raw.end-- - goto scriptDataEscaped - -scriptDataDoubleEscaped: - c = z.readByte() - if z.err != nil { - return - } - switch c { - case '-': - goto scriptDataDoubleEscapedDash - case '<': - goto scriptDataDoubleEscapedLessThanSign - } - goto scriptDataDoubleEscaped - -scriptDataDoubleEscapedDash: - c = z.readByte() - if z.err != nil { - return - } - switch c { - case '-': - goto scriptDataDoubleEscapedDashDash - case '<': - goto scriptDataDoubleEscapedLessThanSign - } - goto scriptDataDoubleEscaped - -scriptDataDoubleEscapedDashDash: - c = z.readByte() - if z.err != nil { - return - } - switch c { - case '-': - goto scriptDataDoubleEscapedDashDash - case '<': - goto scriptDataDoubleEscapedLessThanSign - case '>': - goto scriptData - } - goto scriptDataDoubleEscaped - -scriptDataDoubleEscapedLessThanSign: - c = z.readByte() - if z.err != nil { - return - } - if c == '/' { - goto scriptDataDoubleEscapeEnd - } - z.raw.end-- - goto scriptDataDoubleEscaped - -scriptDataDoubleEscapeEnd: - if z.readRawEndTag() { - z.raw.end += len("</script>") - goto scriptDataEscaped - } - if z.err != nil { - return - } - goto scriptDataDoubleEscaped -} - -// readComment reads the next comment token starting with "<!--". The opening -// "<!--" has already been consumed. -func (z *Tokenizer) readComment() { - z.data.start = z.raw.end - defer func() { - if z.data.end < z.data.start { - // It's a comment with no data, like <!-->. - z.data.end = z.data.start - } - }() - for dashCount := 2; ; { - c := z.readByte() - if z.err != nil { - // Ignore up to two dashes at EOF. - if dashCount > 2 { - dashCount = 2 - } - z.data.end = z.raw.end - dashCount - return - } - switch c { - case '-': - dashCount++ - continue - case '>': - if dashCount >= 2 { - z.data.end = z.raw.end - len("-->") - return - } - case '!': - if dashCount >= 2 { - c = z.readByte() - if z.err != nil { - z.data.end = z.raw.end - return - } - if c == '>' { - z.data.end = z.raw.end - len("--!>") - return - } - } - } - dashCount = 0 - } -} - -// readUntilCloseAngle reads until the next ">". -func (z *Tokenizer) readUntilCloseAngle() { - z.data.start = z.raw.end - for { - c := z.readByte() - if z.err != nil { - z.data.end = z.raw.end - return - } - if c == '>' { - z.data.end = z.raw.end - len(">") - return - } - } -} - -// readMarkupDeclaration reads the next token starting with "<!". It might be -// a "<!--comment-->", a "<!DOCTYPE foo>", a "<![CDATA[section]]>" or -// "<!a bogus comment". The opening "<!" has already been consumed. -func (z *Tokenizer) readMarkupDeclaration() TokenType { - z.data.start = z.raw.end - var c [2]byte - for i := 0; i < 2; i++ { - c[i] = z.readByte() - if z.err != nil { - z.data.end = z.raw.end - return CommentToken - } - } - if c[0] == '-' && c[1] == '-' { - z.readComment() - return CommentToken - } - z.raw.end -= 2 - if z.readDoctype() { - return DoctypeToken - } - if z.allowCDATA && z.readCDATA() { - z.convertNUL = true - return TextToken - } - // It's a bogus comment. - z.readUntilCloseAngle() - return CommentToken -} - -// readDoctype attempts to read a doctype declaration and returns true if -// successful. The opening "<!" has already been consumed. -func (z *Tokenizer) readDoctype() bool { - const s = "DOCTYPE" - for i := 0; i < len(s); i++ { - c := z.readByte() - if z.err != nil { - z.data.end = z.raw.end - return false - } - if c != s[i] && c != s[i]+('a'-'A') { - // Back up to read the fragment of "DOCTYPE" again. - z.raw.end = z.data.start - return false - } - } - if z.skipWhiteSpace(); z.err != nil { - z.data.start = z.raw.end - z.data.end = z.raw.end - return true - } - z.readUntilCloseAngle() - return true -} - -// readCDATA attempts to read a CDATA section and returns true if -// successful. The opening "<!" has already been consumed. -func (z *Tokenizer) readCDATA() bool { - const s = "[CDATA[" - for i := 0; i < len(s); i++ { - c := z.readByte() - if z.err != nil { - z.data.end = z.raw.end - return false - } - if c != s[i] { - // Back up to read the fragment of "[CDATA[" again. - z.raw.end = z.data.start - return false - } - } - z.data.start = z.raw.end - brackets := 0 - for { - c := z.readByte() - if z.err != nil { - z.data.end = z.raw.end - return true - } - switch c { - case ']': - brackets++ - case '>': - if brackets >= 2 { - z.data.end = z.raw.end - len("]]>") - return true - } - brackets = 0 - default: - brackets = 0 - } - } -} - -// startTagIn returns whether the start tag in z.buf[z.data.start:z.data.end] -// case-insensitively matches any element of ss. -func (z *Tokenizer) startTagIn(ss ...string) bool { -loop: - for _, s := range ss { - if z.data.end-z.data.start != len(s) { - continue loop - } - for i := 0; i < len(s); i++ { - c := z.buf[z.data.start+i] - if 'A' <= c && c <= 'Z' { - c += 'a' - 'A' - } - if c != s[i] { - continue loop - } - } - return true - } - return false -} - -// readStartTag reads the next start tag token. The opening "<a" has already -// been consumed, where 'a' means anything in [A-Za-z]. -func (z *Tokenizer) readStartTag() TokenType { - z.readTag(true) - if z.err != nil { - return ErrorToken - } - // Several tags flag the tokenizer's next token as raw. - c, raw := z.buf[z.data.start], false - if 'A' <= c && c <= 'Z' { - c += 'a' - 'A' - } - switch c { - case 'i': - raw = z.startTagIn("iframe") - case 'n': - raw = z.startTagIn("noembed", "noframes", "noscript") - case 'p': - raw = z.startTagIn("plaintext") - case 's': - raw = z.startTagIn("script", "style") - case 't': - raw = z.startTagIn("textarea", "title") - case 'x': - raw = z.startTagIn("xmp") - } - if raw { - z.rawTag = strings.ToLower(string(z.buf[z.data.start:z.data.end])) - } - // Look for a self-closing token like "<br/>". - if z.err == nil && z.buf[z.raw.end-2] == '/' { - return SelfClosingTagToken - } - return StartTagToken -} - -// readTag reads the next tag token and its attributes. If saveAttr, those -// attributes are saved in z.attr, otherwise z.attr is set to an empty slice. -// The opening "<a" or "</a" has already been consumed, where 'a' means anything -// in [A-Za-z]. -func (z *Tokenizer) readTag(saveAttr bool) { - z.attr = z.attr[:0] - z.nAttrReturned = 0 - // Read the tag name and attribute key/value pairs. - z.readTagName() - if z.skipWhiteSpace(); z.err != nil { - return - } - for { - c := z.readByte() - if z.err != nil || c == '>' { - break - } - z.raw.end-- - z.readTagAttrKey() - z.readTagAttrVal() - // Save pendingAttr if saveAttr and that attribute has a non-empty key. - if saveAttr && z.pendingAttr[0].start != z.pendingAttr[0].end { - z.attr = append(z.attr, z.pendingAttr) - } - if z.skipWhiteSpace(); z.err != nil { - break - } - } -} - -// readTagName sets z.data to the "div" in "<div k=v>". The reader (z.raw.end) -// is positioned such that the first byte of the tag name (the "d" in "<div") -// has already been consumed. -func (z *Tokenizer) readTagName() { - z.data.start = z.raw.end - 1 - for { - c := z.readByte() - if z.err != nil { - z.data.end = z.raw.end - return - } - switch c { - case ' ', '\n', '\r', '\t', '\f': - z.data.end = z.raw.end - 1 - return - case '/', '>': - z.raw.end-- - z.data.end = z.raw.end - return - } - } -} - -// readTagAttrKey sets z.pendingAttr[0] to the "k" in "<div k=v>". -// Precondition: z.err == nil. -func (z *Tokenizer) readTagAttrKey() { - z.pendingAttr[0].start = z.raw.end - for { - c := z.readByte() - if z.err != nil { - z.pendingAttr[0].end = z.raw.end - return - } - switch c { - case ' ', '\n', '\r', '\t', '\f', '/': - z.pendingAttr[0].end = z.raw.end - 1 - return - case '=', '>': - z.raw.end-- - z.pendingAttr[0].end = z.raw.end - return - } - } -} - -// readTagAttrVal sets z.pendingAttr[1] to the "v" in "<div k=v>". -func (z *Tokenizer) readTagAttrVal() { - z.pendingAttr[1].start = z.raw.end - z.pendingAttr[1].end = z.raw.end - if z.skipWhiteSpace(); z.err != nil { - return - } - c := z.readByte() - if z.err != nil { - return - } - if c != '=' { - z.raw.end-- - return - } - if z.skipWhiteSpace(); z.err != nil { - return - } - quote := z.readByte() - if z.err != nil { - return - } - switch quote { - case '>': - z.raw.end-- - return - - case '\'', '"': - z.pendingAttr[1].start = z.raw.end - for { - c := z.readByte() - if z.err != nil { - z.pendingAttr[1].end = z.raw.end - return - } - if c == quote { - z.pendingAttr[1].end = z.raw.end - 1 - return - } - } - - default: - z.pendingAttr[1].start = z.raw.end - 1 - for { - c := z.readByte() - if z.err != nil { - z.pendingAttr[1].end = z.raw.end - return - } - switch c { - case ' ', '\n', '\r', '\t', '\f': - z.pendingAttr[1].end = z.raw.end - 1 - return - case '>': - z.raw.end-- - z.pendingAttr[1].end = z.raw.end - return - } - } - } -} - -// Next scans the next token and returns its type. -func (z *Tokenizer) Next() TokenType { - z.raw.start = z.raw.end - z.data.start = z.raw.end - z.data.end = z.raw.end - if z.err != nil { - z.tt = ErrorToken - return z.tt - } - if z.rawTag != "" { - if z.rawTag == "plaintext" { - // Read everything up to EOF. - for z.err == nil { - z.readByte() - } - z.data.end = z.raw.end - z.textIsRaw = true - } else { - z.readRawOrRCDATA() - } - if z.data.end > z.data.start { - z.tt = TextToken - z.convertNUL = true - return z.tt - } - } - z.textIsRaw = false - z.convertNUL = false - -loop: - for { - c := z.readByte() - if z.err != nil { - break loop - } - if c != '<' { - continue loop - } - - // Check if the '<' we have just read is part of a tag, comment - // or doctype. If not, it's part of the accumulated text token. - c = z.readByte() - if z.err != nil { - break loop - } - var tokenType TokenType - switch { - case 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z': - tokenType = StartTagToken - case c == '/': - tokenType = EndTagToken - case c == '!' || c == '?': - // We use CommentToken to mean any of "<!--actual comments-->", - // "<!DOCTYPE declarations>" and "<?xml processing instructions?>". - tokenType = CommentToken - default: - // Reconsume the current character. - z.raw.end-- - continue - } - - // We have a non-text token, but we might have accumulated some text - // before that. If so, we return the text first, and return the non- - // text token on the subsequent call to Next. - if x := z.raw.end - len("<a"); z.raw.start < x { - z.raw.end = x - z.data.end = x - z.tt = TextToken - return z.tt - } - switch tokenType { - case StartTagToken: - z.tt = z.readStartTag() - return z.tt - case EndTagToken: - c = z.readByte() - if z.err != nil { - break loop - } - if c == '>' { - // "</>" does not generate a token at all. Generate an empty comment - // to allow passthrough clients to pick up the data using Raw. - // Reset the tokenizer state and start again. - z.tt = CommentToken - return z.tt - } - if 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z' { - z.readTag(false) - if z.err != nil { - z.tt = ErrorToken - } else { - z.tt = EndTagToken - } - return z.tt - } - z.raw.end-- - z.readUntilCloseAngle() - z.tt = CommentToken - return z.tt - case CommentToken: - if c == '!' { - z.tt = z.readMarkupDeclaration() - return z.tt - } - z.raw.end-- - z.readUntilCloseAngle() - z.tt = CommentToken - return z.tt - } - } - if z.raw.start < z.raw.end { - z.data.end = z.raw.end - z.tt = TextToken - return z.tt - } - z.tt = ErrorToken - return z.tt -} - -// Raw returns the unmodified text of the current token. Calling Next, Token, -// Text, TagName or TagAttr may change the contents of the returned slice. -func (z *Tokenizer) Raw() []byte { - return z.buf[z.raw.start:z.raw.end] -} - -// convertNewlines converts "\r" and "\r\n" in s to "\n". -// The conversion happens in place, but the resulting slice may be shorter. -func convertNewlines(s []byte) []byte { - for i, c := range s { - if c != '\r' { - continue - } - - src := i + 1 - if src >= len(s) || s[src] != '\n' { - s[i] = '\n' - continue - } - - dst := i - for src < len(s) { - if s[src] == '\r' { - if src+1 < len(s) && s[src+1] == '\n' { - src++ - } - s[dst] = '\n' - } else { - s[dst] = s[src] - } - src++ - dst++ - } - return s[:dst] - } - return s -} - -var ( - nul = []byte("\x00") - replacement = []byte("\ufffd") -) - -// Text returns the unescaped text of a text, comment or doctype token. The -// contents of the returned slice may change on the next call to Next. -func (z *Tokenizer) Text() []byte { - switch z.tt { - case TextToken, CommentToken, DoctypeToken: - s := z.buf[z.data.start:z.data.end] - z.data.start = z.raw.end - z.data.end = z.raw.end - s = convertNewlines(s) - if (z.convertNUL || z.tt == CommentToken) && bytes.Contains(s, nul) { - s = bytes.Replace(s, nul, replacement, -1) - } - if !z.textIsRaw { - s = unescape(s, false) - } - return s - } - return nil -} - -// TagName returns the lower-cased name of a tag token (the `img` out of -// `<IMG SRC="foo">`) and whether the tag has attributes. -// The contents of the returned slice may change on the next call to Next. -func (z *Tokenizer) TagName() (name []byte, hasAttr bool) { - if z.data.start < z.data.end { - switch z.tt { - case StartTagToken, EndTagToken, SelfClosingTagToken: - s := z.buf[z.data.start:z.data.end] - z.data.start = z.raw.end - z.data.end = z.raw.end - return lower(s), z.nAttrReturned < len(z.attr) - } - } - return nil, false -} - -// TagAttr returns the lower-cased key and unescaped value of the next unparsed -// attribute for the current tag token and whether there are more attributes. -// The contents of the returned slices may change on the next call to Next. -func (z *Tokenizer) TagAttr() (key, val []byte, moreAttr bool) { - if z.nAttrReturned < len(z.attr) { - switch z.tt { - case StartTagToken, SelfClosingTagToken: - x := z.attr[z.nAttrReturned] - z.nAttrReturned++ - key = z.buf[x[0].start:x[0].end] - val = z.buf[x[1].start:x[1].end] - return lower(key), unescape(convertNewlines(val), true), z.nAttrReturned < len(z.attr) - } - } - return nil, nil, false -} - -// Token returns the current Token. The result's Data and Attr values remain -// valid after subsequent Next calls. -func (z *Tokenizer) Token() Token { - t := Token{Type: z.tt} - switch z.tt { - case TextToken, CommentToken, DoctypeToken: - t.Data = string(z.Text()) - case StartTagToken, SelfClosingTagToken, EndTagToken: - name, moreAttr := z.TagName() - for moreAttr { - var key, val []byte - key, val, moreAttr = z.TagAttr() - t.Attr = append(t.Attr, Attribute{"", atom.String(key), string(val)}) - } - if a := atom.Lookup(name); a != 0 { - t.DataAtom, t.Data = a, a.String() - } else { - t.DataAtom, t.Data = 0, string(name) - } - } - return t -} - -// SetMaxBuf sets a limit on the amount of data buffered during tokenization. -// A value of 0 means unlimited. -func (z *Tokenizer) SetMaxBuf(n int) { - z.maxBuf = n -} - -// NewTokenizer returns a new HTML Tokenizer for the given Reader. -// The input is assumed to be UTF-8 encoded. -func NewTokenizer(r io.Reader) *Tokenizer { - return NewTokenizerFragment(r, "") -} - -// NewTokenizerFragment returns a new HTML Tokenizer for the given Reader, for -// tokenizing an existing element's InnerHTML fragment. contextTag is that -// element's tag, such as "div" or "iframe". -// -// For example, how the InnerHTML "a<b" is tokenized depends on whether it is -// for a <p> tag or a <script> tag. -// -// The input is assumed to be UTF-8 encoded. -func NewTokenizerFragment(r io.Reader, contextTag string) *Tokenizer { - z := &Tokenizer{ - r: r, - buf: make([]byte, 0, 4096), - } - if contextTag != "" { - switch s := strings.ToLower(contextTag); s { - case "iframe", "noembed", "noframes", "noscript", "plaintext", "script", "style", "title", "textarea", "xmp": - z.rawTag = s - } - } - return z -} -- cgit v1.2.3