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Diffstat (limited to 'vendor/golang.org/x/net/html/parse.go')
| -rw-r--r-- | vendor/golang.org/x/net/html/parse.go | 2460 |
1 files changed, 2460 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/html/parse.go b/vendor/golang.org/x/net/html/parse.go new file mode 100644 index 0000000..46a89ed --- /dev/null +++ b/vendor/golang.org/x/net/html/parse.go @@ -0,0 +1,2460 @@ +// 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 ( + "errors" + "fmt" + "io" + "strings" + + a "golang.org/x/net/html/atom" +) + +// A parser implements the HTML5 parsing algorithm: +// https://html.spec.whatwg.org/multipage/syntax.html#tree-construction +type parser struct { + // tokenizer provides the tokens for the parser. + tokenizer *Tokenizer + // tok is the most recently read token. + tok Token + // Self-closing tags like <hr/> are treated as start tags, except that + // hasSelfClosingToken is set while they are being processed. + hasSelfClosingToken bool + // doc is the document root element. + doc *Node + // The stack of open elements (section 12.2.4.2) and active formatting + // elements (section 12.2.4.3). + oe, afe nodeStack + // Element pointers (section 12.2.4.4). + head, form *Node + // Other parsing state flags (section 12.2.4.5). + scripting, framesetOK bool + // The stack of template insertion modes + templateStack insertionModeStack + // im is the current insertion mode. + im insertionMode + // originalIM is the insertion mode to go back to after completing a text + // or inTableText insertion mode. + originalIM insertionMode + // fosterParenting is whether new elements should be inserted according to + // the foster parenting rules (section 12.2.6.1). + fosterParenting bool + // quirks is whether the parser is operating in "quirks mode." + quirks bool + // fragment is whether the parser is parsing an HTML fragment. + fragment bool + // context is the context element when parsing an HTML fragment + // (section 12.4). + context *Node +} + +func (p *parser) top() *Node { + if n := p.oe.top(); n != nil { + return n + } + return p.doc +} + +// Stop tags for use in popUntil. These come from section 12.2.4.2. +var ( + defaultScopeStopTags = map[string][]a.Atom{ + "": {a.Applet, a.Caption, a.Html, a.Table, a.Td, a.Th, a.Marquee, a.Object, a.Template}, + "math": {a.AnnotationXml, a.Mi, a.Mn, a.Mo, a.Ms, a.Mtext}, + "svg": {a.Desc, a.ForeignObject, a.Title}, + } +) + +type scope int + +const ( + defaultScope scope = iota + listItemScope + buttonScope + tableScope + tableRowScope + tableBodyScope + selectScope +) + +// popUntil pops the stack of open elements at the highest element whose tag +// is in matchTags, provided there is no higher element in the scope's stop +// tags (as defined in section 12.2.4.2). It returns whether or not there was +// such an element. If there was not, popUntil leaves the stack unchanged. +// +// For example, the set of stop tags for table scope is: "html", "table". If +// the stack was: +// ["html", "body", "font", "table", "b", "i", "u"] +// then popUntil(tableScope, "font") would return false, but +// popUntil(tableScope, "i") would return true and the stack would become: +// ["html", "body", "font", "table", "b"] +// +// If an element's tag is in both the stop tags and matchTags, then the stack +// will be popped and the function returns true (provided, of course, there was +// no higher element in the stack that was also in the stop tags). For example, +// popUntil(tableScope, "table") returns true and leaves: +// ["html", "body", "font"] +func (p *parser) popUntil(s scope, matchTags ...a.Atom) bool { + if i := p.indexOfElementInScope(s, matchTags...); i != -1 { + p.oe = p.oe[:i] + return true + } + return false +} + +// indexOfElementInScope returns the index in p.oe of the highest element whose +// tag is in matchTags that is in scope. If no matching element is in scope, it +// returns -1. +func (p *parser) indexOfElementInScope(s scope, matchTags ...a.Atom) int { + for i := len(p.oe) - 1; i >= 0; i-- { + tagAtom := p.oe[i].DataAtom + if p.oe[i].Namespace == "" { + for _, t := range matchTags { + if t == tagAtom { + return i + } + } + switch s { + case defaultScope: + // No-op. + case listItemScope: + if tagAtom == a.Ol || tagAtom == a.Ul { + return -1 + } + case buttonScope: + if tagAtom == a.Button { + return -1 + } + case tableScope: + if tagAtom == a.Html || tagAtom == a.Table || tagAtom == a.Template { + return -1 + } + case selectScope: + if tagAtom != a.Optgroup && tagAtom != a.Option { + return -1 + } + default: + panic("unreachable") + } + } + switch s { + case defaultScope, listItemScope, buttonScope: + for _, t := range defaultScopeStopTags[p.oe[i].Namespace] { + if t == tagAtom { + return -1 + } + } + } + } + return -1 +} + +// elementInScope is like popUntil, except that it doesn't modify the stack of +// open elements. +func (p *parser) elementInScope(s scope, matchTags ...a.Atom) bool { + return p.indexOfElementInScope(s, matchTags...) != -1 +} + +// clearStackToContext pops elements off the stack of open elements until a +// scope-defined element is found. +func (p *parser) clearStackToContext(s scope) { + for i := len(p.oe) - 1; i >= 0; i-- { + tagAtom := p.oe[i].DataAtom + switch s { + case tableScope: + if tagAtom == a.Html || tagAtom == a.Table || tagAtom == a.Template { + p.oe = p.oe[:i+1] + return + } + case tableRowScope: + if tagAtom == a.Html || tagAtom == a.Tr || tagAtom == a.Template { + p.oe = p.oe[:i+1] + return + } + case tableBodyScope: + if tagAtom == a.Html || tagAtom == a.Tbody || tagAtom == a.Tfoot || tagAtom == a.Thead || tagAtom == a.Template { + p.oe = p.oe[:i+1] + return + } + default: + panic("unreachable") + } + } +} + +// parseGenericRawTextElement implements the generic raw text element parsing +// algorithm defined in 12.2.6.2. +// https://html.spec.whatwg.org/multipage/parsing.html#parsing-elements-that-contain-only-text +// TODO: Since both RAWTEXT and RCDATA states are treated as tokenizer's part +// officially, need to make tokenizer consider both states. +func (p *parser) parseGenericRawTextElement() { + p.addElement() + p.originalIM = p.im + p.im = textIM +} + +// generateImpliedEndTags pops nodes off the stack of open elements as long as +// the top node has a tag name of dd, dt, li, optgroup, option, p, rb, rp, rt or rtc. +// If exceptions are specified, nodes with that name will not be popped off. +func (p *parser) generateImpliedEndTags(exceptions ...string) { + var i int +loop: + for i = len(p.oe) - 1; i >= 0; i-- { + n := p.oe[i] + if n.Type != ElementNode { + break + } + switch n.DataAtom { + case a.Dd, a.Dt, a.Li, a.Optgroup, a.Option, a.P, a.Rb, a.Rp, a.Rt, a.Rtc: + for _, except := range exceptions { + if n.Data == except { + break loop + } + } + continue + } + break + } + + p.oe = p.oe[:i+1] +} + +// addChild adds a child node n to the top element, and pushes n onto the stack +// of open elements if it is an element node. +func (p *parser) addChild(n *Node) { + if p.shouldFosterParent() { + p.fosterParent(n) + } else { + p.top().AppendChild(n) + } + + if n.Type == ElementNode { + p.oe = append(p.oe, n) + } +} + +// shouldFosterParent returns whether the next node to be added should be +// foster parented. +func (p *parser) shouldFosterParent() bool { + if p.fosterParenting { + switch p.top().DataAtom { + case a.Table, a.Tbody, a.Tfoot, a.Thead, a.Tr: + return true + } + } + return false +} + +// fosterParent adds a child node according to the foster parenting rules. +// Section 12.2.6.1, "foster parenting". +func (p *parser) fosterParent(n *Node) { + var table, parent, prev, template *Node + var i int + for i = len(p.oe) - 1; i >= 0; i-- { + if p.oe[i].DataAtom == a.Table { + table = p.oe[i] + break + } + } + + var j int + for j = len(p.oe) - 1; j >= 0; j-- { + if p.oe[j].DataAtom == a.Template { + template = p.oe[j] + break + } + } + + if template != nil && (table == nil || j > i) { + template.AppendChild(n) + return + } + + if table == nil { + // The foster parent is the html element. + parent = p.oe[0] + } else { + parent = table.Parent + } + if parent == nil { + parent = p.oe[i-1] + } + + if table != nil { + prev = table.PrevSibling + } else { + prev = parent.LastChild + } + if prev != nil && prev.Type == TextNode && n.Type == TextNode { + prev.Data += n.Data + return + } + + parent.InsertBefore(n, table) +} + +// addText adds text to the preceding node if it is a text node, or else it +// calls addChild with a new text node. +func (p *parser) addText(text string) { + if text == "" { + return + } + + if p.shouldFosterParent() { + p.fosterParent(&Node{ + Type: TextNode, + Data: text, + }) + return + } + + t := p.top() + if n := t.LastChild; n != nil && n.Type == TextNode { + n.Data += text + return + } + p.addChild(&Node{ + Type: TextNode, + Data: text, + }) +} + +// addElement adds a child element based on the current token. +func (p *parser) addElement() { + p.addChild(&Node{ + Type: ElementNode, + DataAtom: p.tok.DataAtom, + Data: p.tok.Data, + Attr: p.tok.Attr, + }) +} + +// Section 12.2.4.3. +func (p *parser) addFormattingElement() { + tagAtom, attr := p.tok.DataAtom, p.tok.Attr + p.addElement() + + // Implement the Noah's Ark clause, but with three per family instead of two. + identicalElements := 0 +findIdenticalElements: + for i := len(p.afe) - 1; i >= 0; i-- { + n := p.afe[i] + if n.Type == scopeMarkerNode { + break + } + if n.Type != ElementNode { + continue + } + if n.Namespace != "" { + continue + } + if n.DataAtom != tagAtom { + continue + } + if len(n.Attr) != len(attr) { + continue + } + compareAttributes: + for _, t0 := range n.Attr { + for _, t1 := range attr { + if t0.Key == t1.Key && t0.Namespace == t1.Namespace && t0.Val == t1.Val { + // Found a match for this attribute, continue with the next attribute. + continue compareAttributes + } + } + // If we get here, there is no attribute that matches a. + // Therefore the element is not identical to the new one. + continue findIdenticalElements + } + + identicalElements++ + if identicalElements >= 3 { + p.afe.remove(n) + } + } + + p.afe = append(p.afe, p.top()) +} + +// Section 12.2.4.3. +func (p *parser) clearActiveFormattingElements() { + for { + if n := p.afe.pop(); len(p.afe) == 0 || n.Type == scopeMarkerNode { + return + } + } +} + +// Section 12.2.4.3. +func (p *parser) reconstructActiveFormattingElements() { + n := p.afe.top() + if n == nil { + return + } + if n.Type == scopeMarkerNode || p.oe.index(n) != -1 { + return + } + i := len(p.afe) - 1 + for n.Type != scopeMarkerNode && p.oe.index(n) == -1 { + if i == 0 { + i = -1 + break + } + i-- + n = p.afe[i] + } + for { + i++ + clone := p.afe[i].clone() + p.addChild(clone) + p.afe[i] = clone + if i == len(p.afe)-1 { + break + } + } +} + +// Section 12.2.5. +func (p *parser) acknowledgeSelfClosingTag() { + p.hasSelfClosingToken = false +} + +// An insertion mode (section 12.2.4.1) is the state transition function from +// a particular state in the HTML5 parser's state machine. It updates the +// parser's fields depending on parser.tok (where ErrorToken means EOF). +// It returns whether the token was consumed. +type insertionMode func(*parser) bool + +// setOriginalIM sets the insertion mode to return to after completing a text or +// inTableText insertion mode. +// Section 12.2.4.1, "using the rules for". +func (p *parser) setOriginalIM() { + if p.originalIM != nil { + panic("html: bad parser state: originalIM was set twice") + } + p.originalIM = p.im +} + +// Section 12.2.4.1, "reset the insertion mode". +func (p *parser) resetInsertionMode() { + for i := len(p.oe) - 1; i >= 0; i-- { + n := p.oe[i] + last := i == 0 + if last && p.context != nil { + n = p.context + } + + switch n.DataAtom { + case a.Select: + if !last { + for ancestor, first := n, p.oe[0]; ancestor != first; { + ancestor = p.oe[p.oe.index(ancestor)-1] + switch ancestor.DataAtom { + case a.Template: + p.im = inSelectIM + return + case a.Table: + p.im = inSelectInTableIM + return + } + } + } + p.im = inSelectIM + case a.Td, a.Th: + // TODO: remove this divergence from the HTML5 spec. + // + // See https://bugs.chromium.org/p/chromium/issues/detail?id=829668 + p.im = inCellIM + case a.Tr: + p.im = inRowIM + case a.Tbody, a.Thead, a.Tfoot: + p.im = inTableBodyIM + case a.Caption: + p.im = inCaptionIM + case a.Colgroup: + p.im = inColumnGroupIM + case a.Table: + p.im = inTableIM + case a.Template: + // TODO: remove this divergence from the HTML5 spec. + if n.Namespace != "" { + continue + } + p.im = p.templateStack.top() + case a.Head: + // TODO: remove this divergence from the HTML5 spec. + // + // See https://bugs.chromium.org/p/chromium/issues/detail?id=829668 + p.im = inHeadIM + case a.Body: + p.im = inBodyIM + case a.Frameset: + p.im = inFramesetIM + case a.Html: + if p.head == nil { + p.im = beforeHeadIM + } else { + p.im = afterHeadIM + } + default: + if last { + p.im = inBodyIM + return + } + continue + } + return + } +} + +const whitespace = " \t\r\n\f" + +// Section 12.2.6.4.1. +func initialIM(p *parser) bool { + switch p.tok.Type { + case TextToken: + p.tok.Data = strings.TrimLeft(p.tok.Data, whitespace) + if len(p.tok.Data) == 0 { + // It was all whitespace, so ignore it. + return true + } + case CommentToken: + p.doc.AppendChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + return true + case DoctypeToken: + n, quirks := parseDoctype(p.tok.Data) + p.doc.AppendChild(n) + p.quirks = quirks + p.im = beforeHTMLIM + return true + } + p.quirks = true + p.im = beforeHTMLIM + return false +} + +// Section 12.2.6.4.2. +func beforeHTMLIM(p *parser) bool { + switch p.tok.Type { + case DoctypeToken: + // Ignore the token. + return true + case TextToken: + p.tok.Data = strings.TrimLeft(p.tok.Data, whitespace) + if len(p.tok.Data) == 0 { + // It was all whitespace, so ignore it. + return true + } + case StartTagToken: + if p.tok.DataAtom == a.Html { + p.addElement() + p.im = beforeHeadIM + return true + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Head, a.Body, a.Html, a.Br: + p.parseImpliedToken(StartTagToken, a.Html, a.Html.String()) + return false + default: + // Ignore the token. + return true + } + case CommentToken: + p.doc.AppendChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + return true + } + p.parseImpliedToken(StartTagToken, a.Html, a.Html.String()) + return false +} + +// Section 12.2.6.4.3. +func beforeHeadIM(p *parser) bool { + switch p.tok.Type { + case TextToken: + p.tok.Data = strings.TrimLeft(p.tok.Data, whitespace) + if len(p.tok.Data) == 0 { + // It was all whitespace, so ignore it. + return true + } + case StartTagToken: + switch p.tok.DataAtom { + case a.Head: + p.addElement() + p.head = p.top() + p.im = inHeadIM + return true + case a.Html: + return inBodyIM(p) + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Head, a.Body, a.Html, a.Br: + p.parseImpliedToken(StartTagToken, a.Head, a.Head.String()) + return false + default: + // Ignore the token. + return true + } + case CommentToken: + p.addChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + return true + case DoctypeToken: + // Ignore the token. + return true + } + + p.parseImpliedToken(StartTagToken, a.Head, a.Head.String()) + return false +} + +// Section 12.2.6.4.4. +func inHeadIM(p *parser) bool { + switch p.tok.Type { + case TextToken: + s := strings.TrimLeft(p.tok.Data, whitespace) + if len(s) < len(p.tok.Data) { + // Add the initial whitespace to the current node. + p.addText(p.tok.Data[:len(p.tok.Data)-len(s)]) + if s == "" { + return true + } + p.tok.Data = s + } + case StartTagToken: + switch p.tok.DataAtom { + case a.Html: + return inBodyIM(p) + case a.Base, a.Basefont, a.Bgsound, a.Link, a.Meta: + p.addElement() + p.oe.pop() + p.acknowledgeSelfClosingTag() + return true + case a.Noscript: + if p.scripting { + p.parseGenericRawTextElement() + return true + } + p.addElement() + p.im = inHeadNoscriptIM + // Don't let the tokenizer go into raw text mode when scripting is disabled. + p.tokenizer.NextIsNotRawText() + return true + case a.Script, a.Title: + p.addElement() + p.setOriginalIM() + p.im = textIM + return true + case a.Noframes, a.Style: + p.parseGenericRawTextElement() + return true + case a.Head: + // Ignore the token. + return true + case a.Template: + // TODO: remove this divergence from the HTML5 spec. + // + // We don't handle all of the corner cases when mixing foreign + // content (i.e. <math> or <svg>) with <template>. Without this + // early return, we can get into an infinite loop, possibly because + // of the "TODO... further divergence" a little below. + // + // As a workaround, if we are mixing foreign content and templates, + // just ignore the rest of the HTML. Foreign content is rare and a + // relatively old HTML feature. Templates are also rare and a + // relatively new HTML feature. Their combination is very rare. + for _, e := range p.oe { + if e.Namespace != "" { + p.im = ignoreTheRemainingTokens + return true + } + } + + p.addElement() + p.afe = append(p.afe, &scopeMarker) + p.framesetOK = false + p.im = inTemplateIM + p.templateStack = append(p.templateStack, inTemplateIM) + return true + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Head: + p.oe.pop() + p.im = afterHeadIM + return true + case a.Body, a.Html, a.Br: + p.parseImpliedToken(EndTagToken, a.Head, a.Head.String()) + return false + case a.Template: + if !p.oe.contains(a.Template) { + return true + } + // TODO: remove this further divergence from the HTML5 spec. + // + // See https://bugs.chromium.org/p/chromium/issues/detail?id=829668 + p.generateImpliedEndTags() + for i := len(p.oe) - 1; i >= 0; i-- { + if n := p.oe[i]; n.Namespace == "" && n.DataAtom == a.Template { + p.oe = p.oe[:i] + break + } + } + p.clearActiveFormattingElements() + p.templateStack.pop() + p.resetInsertionMode() + return true + default: + // Ignore the token. + return true + } + case CommentToken: + p.addChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + return true + case DoctypeToken: + // Ignore the token. + return true + } + + p.parseImpliedToken(EndTagToken, a.Head, a.Head.String()) + return false +} + +// Section 12.2.6.4.5. +func inHeadNoscriptIM(p *parser) bool { + switch p.tok.Type { + case DoctypeToken: + // Ignore the token. + return true + case StartTagToken: + switch p.tok.DataAtom { + case a.Html: + return inBodyIM(p) + case a.Basefont, a.Bgsound, a.Link, a.Meta, a.Noframes, a.Style: + return inHeadIM(p) + case a.Head: + // Ignore the token. + return true + case a.Noscript: + // Don't let the tokenizer go into raw text mode even when a <noscript> + // tag is in "in head noscript" insertion mode. + p.tokenizer.NextIsNotRawText() + // Ignore the token. + return true + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Noscript, a.Br: + default: + // Ignore the token. + return true + } + case TextToken: + s := strings.TrimLeft(p.tok.Data, whitespace) + if len(s) == 0 { + // It was all whitespace. + return inHeadIM(p) + } + case CommentToken: + return inHeadIM(p) + } + p.oe.pop() + if p.top().DataAtom != a.Head { + panic("html: the new current node will be a head element.") + } + p.im = inHeadIM + if p.tok.DataAtom == a.Noscript { + return true + } + return false +} + +// Section 12.2.6.4.6. +func afterHeadIM(p *parser) bool { + switch p.tok.Type { + case TextToken: + s := strings.TrimLeft(p.tok.Data, whitespace) + if len(s) < len(p.tok.Data) { + // Add the initial whitespace to the current node. + p.addText(p.tok.Data[:len(p.tok.Data)-len(s)]) + if s == "" { + return true + } + p.tok.Data = s + } + case StartTagToken: + switch p.tok.DataAtom { + case a.Html: + return inBodyIM(p) + case a.Body: + p.addElement() + p.framesetOK = false + p.im = inBodyIM + return true + case a.Frameset: + p.addElement() + p.im = inFramesetIM + return true + case a.Base, a.Basefont, a.Bgsound, a.Link, a.Meta, a.Noframes, a.Script, a.Style, a.Template, a.Title: + p.oe = append(p.oe, p.head) + defer p.oe.remove(p.head) + return inHeadIM(p) + case a.Head: + // Ignore the token. + return true + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Body, a.Html, a.Br: + // Drop down to creating an implied <body> tag. + case a.Template: + return inHeadIM(p) + default: + // Ignore the token. + return true + } + case CommentToken: + p.addChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + return true + case DoctypeToken: + // Ignore the token. + return true + } + + p.parseImpliedToken(StartTagToken, a.Body, a.Body.String()) + p.framesetOK = true + return false +} + +// copyAttributes copies attributes of src not found on dst to dst. +func copyAttributes(dst *Node, src Token) { + if len(src.Attr) == 0 { + return + } + attr := map[string]string{} + for _, t := range dst.Attr { + attr[t.Key] = t.Val + } + for _, t := range src.Attr { + if _, ok := attr[t.Key]; !ok { + dst.Attr = append(dst.Attr, t) + attr[t.Key] = t.Val + } + } +} + +// Section 12.2.6.4.7. +func inBodyIM(p *parser) bool { + switch p.tok.Type { + case TextToken: + d := p.tok.Data + switch n := p.oe.top(); n.DataAtom { + case a.Pre, a.Listing: + if n.FirstChild == nil { + // Ignore a newline at the start of a <pre> block. + if d != "" && d[0] == '\r' { + d = d[1:] + } + if d != "" && d[0] == '\n' { + d = d[1:] + } + } + } + d = strings.Replace(d, "\x00", "", -1) + if d == "" { + return true + } + p.reconstructActiveFormattingElements() + p.addText(d) + if p.framesetOK && strings.TrimLeft(d, whitespace) != "" { + // There were non-whitespace characters inserted. + p.framesetOK = false + } + case StartTagToken: + switch p.tok.DataAtom { + case a.Html: + if p.oe.contains(a.Template) { + return true + } + copyAttributes(p.oe[0], p.tok) + case a.Base, a.Basefont, a.Bgsound, a.Link, a.Meta, a.Noframes, a.Script, a.Style, a.Template, a.Title: + return inHeadIM(p) + case a.Body: + if p.oe.contains(a.Template) { + return true + } + if len(p.oe) >= 2 { + body := p.oe[1] + if body.Type == ElementNode && body.DataAtom == a.Body { + p.framesetOK = false + copyAttributes(body, p.tok) + } + } + case a.Frameset: + if !p.framesetOK || len(p.oe) < 2 || p.oe[1].DataAtom != a.Body { + // Ignore the token. + return true + } + body := p.oe[1] + if body.Parent != nil { + body.Parent.RemoveChild(body) + } + p.oe = p.oe[:1] + p.addElement() + p.im = inFramesetIM + return true + case a.Address, a.Article, a.Aside, a.Blockquote, a.Center, a.Details, a.Dialog, a.Dir, a.Div, a.Dl, a.Fieldset, a.Figcaption, a.Figure, a.Footer, a.Header, a.Hgroup, a.Main, a.Menu, a.Nav, a.Ol, a.P, a.Section, a.Summary, a.Ul: + p.popUntil(buttonScope, a.P) + p.addElement() + case a.H1, a.H2, a.H3, a.H4, a.H5, a.H6: + p.popUntil(buttonScope, a.P) + switch n := p.top(); n.DataAtom { + case a.H1, a.H2, a.H3, a.H4, a.H5, a.H6: + p.oe.pop() + } + p.addElement() + case a.Pre, a.Listing: + p.popUntil(buttonScope, a.P) + p.addElement() + // The newline, if any, will be dealt with by the TextToken case. + p.framesetOK = false + case a.Form: + if p.form != nil && !p.oe.contains(a.Template) { + // Ignore the token + return true + } + p.popUntil(buttonScope, a.P) + p.addElement() + if !p.oe.contains(a.Template) { + p.form = p.top() + } + case a.Li: + p.framesetOK = false + for i := len(p.oe) - 1; i >= 0; i-- { + node := p.oe[i] + switch node.DataAtom { + case a.Li: + p.oe = p.oe[:i] + case a.Address, a.Div, a.P: + continue + default: + if !isSpecialElement(node) { + continue + } + } + break + } + p.popUntil(buttonScope, a.P) + p.addElement() + case a.Dd, a.Dt: + p.framesetOK = false + for i := len(p.oe) - 1; i >= 0; i-- { + node := p.oe[i] + switch node.DataAtom { + case a.Dd, a.Dt: + p.oe = p.oe[:i] + case a.Address, a.Div, a.P: + continue + default: + if !isSpecialElement(node) { + continue + } + } + break + } + p.popUntil(buttonScope, a.P) + p.addElement() + case a.Plaintext: + p.popUntil(buttonScope, a.P) + p.addElement() + case a.Button: + p.popUntil(defaultScope, a.Button) + p.reconstructActiveFormattingElements() + p.addElement() + p.framesetOK = false + case a.A: + for i := len(p.afe) - 1; i >= 0 && p.afe[i].Type != scopeMarkerNode; i-- { + if n := p.afe[i]; n.Type == ElementNode && n.DataAtom == a.A { + p.inBodyEndTagFormatting(a.A, "a") + p.oe.remove(n) + p.afe.remove(n) + break + } + } + p.reconstructActiveFormattingElements() + p.addFormattingElement() + case a.B, a.Big, a.Code, a.Em, a.Font, a.I, a.S, a.Small, a.Strike, a.Strong, a.Tt, a.U: + p.reconstructActiveFormattingElements() + p.addFormattingElement() + case a.Nobr: + p.reconstructActiveFormattingElements() + if p.elementInScope(defaultScope, a.Nobr) { + p.inBodyEndTagFormatting(a.Nobr, "nobr") + p.reconstructActiveFormattingElements() + } + p.addFormattingElement() + case a.Applet, a.Marquee, a.Object: + p.reconstructActiveFormattingElements() + p.addElement() + p.afe = append(p.afe, &scopeMarker) + p.framesetOK = false + case a.Table: + if !p.quirks { + p.popUntil(buttonScope, a.P) + } + p.addElement() + p.framesetOK = false + p.im = inTableIM + return true + case a.Area, a.Br, a.Embed, a.Img, a.Input, a.Keygen, a.Wbr: + p.reconstructActiveFormattingElements() + p.addElement() + p.oe.pop() + p.acknowledgeSelfClosingTag() + if p.tok.DataAtom == a.Input { + for _, t := range p.tok.Attr { + if t.Key == "type" { + if strings.ToLower(t.Val) == "hidden" { + // Skip setting framesetOK = false + return true + } + } + } + } + p.framesetOK = false + case a.Param, a.Source, a.Track: + p.addElement() + p.oe.pop() + p.acknowledgeSelfClosingTag() + case a.Hr: + p.popUntil(buttonScope, a.P) + p.addElement() + p.oe.pop() + p.acknowledgeSelfClosingTag() + p.framesetOK = false + case a.Image: + p.tok.DataAtom = a.Img + p.tok.Data = a.Img.String() + return false + case a.Textarea: + p.addElement() + p.setOriginalIM() + p.framesetOK = false + p.im = textIM + case a.Xmp: + p.popUntil(buttonScope, a.P) + p.reconstructActiveFormattingElements() + p.framesetOK = false + p.parseGenericRawTextElement() + case a.Iframe: + p.framesetOK = false + p.parseGenericRawTextElement() + case a.Noembed: + p.parseGenericRawTextElement() + case a.Noscript: + if p.scripting { + p.parseGenericRawTextElement() + return true + } + p.reconstructActiveFormattingElements() + p.addElement() + // Don't let the tokenizer go into raw text mode when scripting is disabled. + p.tokenizer.NextIsNotRawText() + case a.Select: + p.reconstructActiveFormattingElements() + p.addElement() + p.framesetOK = false + p.im = inSelectIM + return true + case a.Optgroup, a.Option: + if p.top().DataAtom == a.Option { + p.oe.pop() + } + p.reconstructActiveFormattingElements() + p.addElement() + case a.Rb, a.Rtc: + if p.elementInScope(defaultScope, a.Ruby) { + p.generateImpliedEndTags() + } + p.addElement() + case a.Rp, a.Rt: + if p.elementInScope(defaultScope, a.Ruby) { + p.generateImpliedEndTags("rtc") + } + p.addElement() + case a.Math, a.Svg: + p.reconstructActiveFormattingElements() + if p.tok.DataAtom == a.Math { + adjustAttributeNames(p.tok.Attr, mathMLAttributeAdjustments) + } else { + adjustAttributeNames(p.tok.Attr, svgAttributeAdjustments) + } + adjustForeignAttributes(p.tok.Attr) + p.addElement() + p.top().Namespace = p.tok.Data + if p.hasSelfClosingToken { + p.oe.pop() + p.acknowledgeSelfClosingTag() + } + return true + case a.Caption, a.Col, a.Colgroup, a.Frame, a.Head, a.Tbody, a.Td, a.Tfoot, a.Th, a.Thead, a.Tr: + // Ignore the token. + default: + p.reconstructActiveFormattingElements() + p.addElement() + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Body: + if p.elementInScope(defaultScope, a.Body) { + p.im = afterBodyIM + } + case a.Html: + if p.elementInScope(defaultScope, a.Body) { + p.parseImpliedToken(EndTagToken, a.Body, a.Body.String()) + return false + } + return true + case a.Address, a.Article, a.Aside, a.Blockquote, a.Button, a.Center, a.Details, a.Dialog, a.Dir, a.Div, a.Dl, a.Fieldset, a.Figcaption, a.Figure, a.Footer, a.Header, a.Hgroup, a.Listing, a.Main, a.Menu, a.Nav, a.Ol, a.Pre, a.Section, a.Summary, a.Ul: + p.popUntil(defaultScope, p.tok.DataAtom) + case a.Form: + if p.oe.contains(a.Template) { + i := p.indexOfElementInScope(defaultScope, a.Form) + if i == -1 { + // Ignore the token. + return true + } + p.generateImpliedEndTags() + if p.oe[i].DataAtom != a.Form { + // Ignore the token. + return true + } + p.popUntil(defaultScope, a.Form) + } else { + node := p.form + p.form = nil + i := p.indexOfElementInScope(defaultScope, a.Form) + if node == nil || i == -1 || p.oe[i] != node { + // Ignore the token. + return true + } + p.generateImpliedEndTags() + p.oe.remove(node) + } + case a.P: + if !p.elementInScope(buttonScope, a.P) { + p.parseImpliedToken(StartTagToken, a.P, a.P.String()) + } + p.popUntil(buttonScope, a.P) + case a.Li: + p.popUntil(listItemScope, a.Li) + case a.Dd, a.Dt: + p.popUntil(defaultScope, p.tok.DataAtom) + case a.H1, a.H2, a.H3, a.H4, a.H5, a.H6: + p.popUntil(defaultScope, a.H1, a.H2, a.H3, a.H4, a.H5, a.H6) + case a.A, a.B, a.Big, a.Code, a.Em, a.Font, a.I, a.Nobr, a.S, a.Small, a.Strike, a.Strong, a.Tt, a.U: + p.inBodyEndTagFormatting(p.tok.DataAtom, p.tok.Data) + case a.Applet, a.Marquee, a.Object: + if p.popUntil(defaultScope, p.tok.DataAtom) { + p.clearActiveFormattingElements() + } + case a.Br: + p.tok.Type = StartTagToken + return false + case a.Template: + return inHeadIM(p) + default: + p.inBodyEndTagOther(p.tok.DataAtom, p.tok.Data) + } + case CommentToken: + p.addChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + case ErrorToken: + // TODO: remove this divergence from the HTML5 spec. + if len(p.templateStack) > 0 { + p.im = inTemplateIM + return false + } + for _, e := range p.oe { + switch e.DataAtom { + case a.Dd, a.Dt, a.Li, a.Optgroup, a.Option, a.P, a.Rb, a.Rp, a.Rt, a.Rtc, a.Tbody, a.Td, a.Tfoot, a.Th, + a.Thead, a.Tr, a.Body, a.Html: + default: + return true + } + } + } + + return true +} + +func (p *parser) inBodyEndTagFormatting(tagAtom a.Atom, tagName string) { + // This is the "adoption agency" algorithm, described at + // https://html.spec.whatwg.org/multipage/syntax.html#adoptionAgency + + // TODO: this is a fairly literal line-by-line translation of that algorithm. + // Once the code successfully parses the comprehensive test suite, we should + // refactor this code to be more idiomatic. + + // Steps 1-2 + if current := p.oe.top(); current.Data == tagName && p.afe.index(current) == -1 { + p.oe.pop() + return + } + + // Steps 3-5. The outer loop. + for i := 0; i < 8; i++ { + // Step 6. Find the formatting element. + var formattingElement *Node + for j := len(p.afe) - 1; j >= 0; j-- { + if p.afe[j].Type == scopeMarkerNode { + break + } + if p.afe[j].DataAtom == tagAtom { + formattingElement = p.afe[j] + break + } + } + if formattingElement == nil { + p.inBodyEndTagOther(tagAtom, tagName) + return + } + + // Step 7. Ignore the tag if formatting element is not in the stack of open elements. + feIndex := p.oe.index(formattingElement) + if feIndex == -1 { + p.afe.remove(formattingElement) + return + } + // Step 8. Ignore the tag if formatting element is not in the scope. + if !p.elementInScope(defaultScope, tagAtom) { + // Ignore the tag. + return + } + + // Step 9. This step is omitted because it's just a parse error but no need to return. + + // Steps 10-11. Find the furthest block. + var furthestBlock *Node + for _, e := range p.oe[feIndex:] { + if isSpecialElement(e) { + furthestBlock = e + break + } + } + if furthestBlock == nil { + e := p.oe.pop() + for e != formattingElement { + e = p.oe.pop() + } + p.afe.remove(e) + return + } + + // Steps 12-13. Find the common ancestor and bookmark node. + commonAncestor := p.oe[feIndex-1] + bookmark := p.afe.index(formattingElement) + + // Step 14. The inner loop. Find the lastNode to reparent. + lastNode := furthestBlock + node := furthestBlock + x := p.oe.index(node) + // Step 14.1. + j := 0 + for { + // Step 14.2. + j++ + // Step. 14.3. + x-- + node = p.oe[x] + // Step 14.4. Go to the next step if node is formatting element. + if node == formattingElement { + break + } + // Step 14.5. Remove node from the list of active formatting elements if + // inner loop counter is greater than three and node is in the list of + // active formatting elements. + if ni := p.afe.index(node); j > 3 && ni > -1 { + p.afe.remove(node) + // If any element of the list of active formatting elements is removed, + // we need to take care whether bookmark should be decremented or not. + // This is because the value of bookmark may exceed the size of the + // list by removing elements from the list. + if ni <= bookmark { + bookmark-- + } + continue + } + // Step 14.6. Continue the next inner loop if node is not in the list of + // active formatting elements. + if p.afe.index(node) == -1 { + p.oe.remove(node) + continue + } + // Step 14.7. + clone := node.clone() + p.afe[p.afe.index(node)] = clone + p.oe[p.oe.index(node)] = clone + node = clone + // Step 14.8. + if lastNode == furthestBlock { + bookmark = p.afe.index(node) + 1 + } + // Step 14.9. + if lastNode.Parent != nil { + lastNode.Parent.RemoveChild(lastNode) + } + node.AppendChild(lastNode) + // Step 14.10. + lastNode = node + } + + // Step 15. Reparent lastNode to the common ancestor, + // or for misnested table nodes, to the foster parent. + if lastNode.Parent != nil { + lastNode.Parent.RemoveChild(lastNode) + } + switch commonAncestor.DataAtom { + case a.Table, a.Tbody, a.Tfoot, a.Thead, a.Tr: + p.fosterParent(lastNode) + default: + commonAncestor.AppendChild(lastNode) + } + + // Steps 16-18. Reparent nodes from the furthest block's children + // to a clone of the formatting element. + clone := formattingElement.clone() + reparentChildren(clone, furthestBlock) + furthestBlock.AppendChild(clone) + + // Step 19. Fix up the list of active formatting elements. + if oldLoc := p.afe.index(formattingElement); oldLoc != -1 && oldLoc < bookmark { + // Move the bookmark with the rest of the list. + bookmark-- + } + p.afe.remove(formattingElement) + p.afe.insert(bookmark, clone) + + // Step 20. Fix up the stack of open elements. + p.oe.remove(formattingElement) + p.oe.insert(p.oe.index(furthestBlock)+1, clone) + } +} + +// inBodyEndTagOther performs the "any other end tag" algorithm for inBodyIM. +// "Any other end tag" handling from 12.2.6.5 The rules for parsing tokens in foreign content +// https://html.spec.whatwg.org/multipage/syntax.html#parsing-main-inforeign +func (p *parser) inBodyEndTagOther(tagAtom a.Atom, tagName string) { + for i := len(p.oe) - 1; i >= 0; i-- { + // Two element nodes have the same tag if they have the same Data (a + // string-typed field). As an optimization, for common HTML tags, each + // Data string is assigned a unique, non-zero DataAtom (a uint32-typed + // field), since integer comparison is faster than string comparison. + // Uncommon (custom) tags get a zero DataAtom. + // + // The if condition here is equivalent to (p.oe[i].Data == tagName). + if (p.oe[i].DataAtom == tagAtom) && + ((tagAtom != 0) || (p.oe[i].Data == tagName)) { + p.oe = p.oe[:i] + break + } + if isSpecialElement(p.oe[i]) { + break + } + } +} + +// Section 12.2.6.4.8. +func textIM(p *parser) bool { + switch p.tok.Type { + case ErrorToken: + p.oe.pop() + case TextToken: + d := p.tok.Data + if n := p.oe.top(); n.DataAtom == a.Textarea && n.FirstChild == nil { + // Ignore a newline at the start of a <textarea> block. + if d != "" && d[0] == '\r' { + d = d[1:] + } + if d != "" && d[0] == '\n' { + d = d[1:] + } + } + if d == "" { + return true + } + p.addText(d) + return true + case EndTagToken: + p.oe.pop() + } + p.im = p.originalIM + p.originalIM = nil + return p.tok.Type == EndTagToken +} + +// Section 12.2.6.4.9. +func inTableIM(p *parser) bool { + switch p.tok.Type { + case TextToken: + p.tok.Data = strings.Replace(p.tok.Data, "\x00", "", -1) + switch p.oe.top().DataAtom { + case a.Table, a.Tbody, a.Tfoot, a.Thead, a.Tr: + if strings.Trim(p.tok.Data, whitespace) == "" { + p.addText(p.tok.Data) + return true + } + } + case StartTagToken: + switch p.tok.DataAtom { + case a.Caption: + p.clearStackToContext(tableScope) + p.afe = append(p.afe, &scopeMarker) + p.addElement() + p.im = inCaptionIM + return true + case a.Colgroup: + p.clearStackToContext(tableScope) + p.addElement() + p.im = inColumnGroupIM + return true + case a.Col: + p.parseImpliedToken(StartTagToken, a.Colgroup, a.Colgroup.String()) + return false + case a.Tbody, a.Tfoot, a.Thead: + p.clearStackToContext(tableScope) + p.addElement() + p.im = inTableBodyIM + return true + case a.Td, a.Th, a.Tr: + p.parseImpliedToken(StartTagToken, a.Tbody, a.Tbody.String()) + return false + case a.Table: + if p.popUntil(tableScope, a.Table) { + p.resetInsertionMode() + return false + } + // Ignore the token. + return true + case a.Style, a.Script, a.Template: + return inHeadIM(p) + case a.Input: + for _, t := range p.tok.Attr { + if t.Key == "type" && strings.ToLower(t.Val) == "hidden" { + p.addElement() + p.oe.pop() + return true + } + } + // Otherwise drop down to the default action. + case a.Form: + if p.oe.contains(a.Template) || p.form != nil { + // Ignore the token. + return true + } + p.addElement() + p.form = p.oe.pop() + case a.Select: + p.reconstructActiveFormattingElements() + switch p.top().DataAtom { + case a.Table, a.Tbody, a.Tfoot, a.Thead, a.Tr: + p.fosterParenting = true + } + p.addElement() + p.fosterParenting = false + p.framesetOK = false + p.im = inSelectInTableIM + return true + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Table: + if p.popUntil(tableScope, a.Table) { + p.resetInsertionMode() + return true + } + // Ignore the token. + return true + case a.Body, a.Caption, a.Col, a.Colgroup, a.Html, a.Tbody, a.Td, a.Tfoot, a.Th, a.Thead, a.Tr: + // Ignore the token. + return true + case a.Template: + return inHeadIM(p) + } + case CommentToken: + p.addChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + return true + case DoctypeToken: + // Ignore the token. + return true + case ErrorToken: + return inBodyIM(p) + } + + p.fosterParenting = true + defer func() { p.fosterParenting = false }() + + return inBodyIM(p) +} + +// Section 12.2.6.4.11. +func inCaptionIM(p *parser) bool { + switch p.tok.Type { + case StartTagToken: + switch p.tok.DataAtom { + case a.Caption, a.Col, a.Colgroup, a.Tbody, a.Td, a.Tfoot, a.Thead, a.Tr: + if !p.popUntil(tableScope, a.Caption) { + // Ignore the token. + return true + } + p.clearActiveFormattingElements() + p.im = inTableIM + return false + case a.Select: + p.reconstructActiveFormattingElements() + p.addElement() + p.framesetOK = false + p.im = inSelectInTableIM + return true + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Caption: + if p.popUntil(tableScope, a.Caption) { + p.clearActiveFormattingElements() + p.im = inTableIM + } + return true + case a.Table: + if !p.popUntil(tableScope, a.Caption) { + // Ignore the token. + return true + } + p.clearActiveFormattingElements() + p.im = inTableIM + return false + case a.Body, a.Col, a.Colgroup, a.Html, a.Tbody, a.Td, a.Tfoot, a.Th, a.Thead, a.Tr: + // Ignore the token. + return true + } + } + return inBodyIM(p) +} + +// Section 12.2.6.4.12. +func inColumnGroupIM(p *parser) bool { + switch p.tok.Type { + case TextToken: + s := strings.TrimLeft(p.tok.Data, whitespace) + if len(s) < len(p.tok.Data) { + // Add the initial whitespace to the current node. + p.addText(p.tok.Data[:len(p.tok.Data)-len(s)]) + if s == "" { + return true + } + p.tok.Data = s + } + case CommentToken: + p.addChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + return true + case DoctypeToken: + // Ignore the token. + return true + case StartTagToken: + switch p.tok.DataAtom { + case a.Html: + return inBodyIM(p) + case a.Col: + p.addElement() + p.oe.pop() + p.acknowledgeSelfClosingTag() + return true + case a.Template: + return inHeadIM(p) + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Colgroup: + if p.oe.top().DataAtom == a.Colgroup { + p.oe.pop() + p.im = inTableIM + } + return true + case a.Col: + // Ignore the token. + return true + case a.Template: + return inHeadIM(p) + } + case ErrorToken: + return inBodyIM(p) + } + if p.oe.top().DataAtom != a.Colgroup { + return true + } + p.oe.pop() + p.im = inTableIM + return false +} + +// Section 12.2.6.4.13. +func inTableBodyIM(p *parser) bool { + switch p.tok.Type { + case StartTagToken: + switch p.tok.DataAtom { + case a.Tr: + p.clearStackToContext(tableBodyScope) + p.addElement() + p.im = inRowIM + return true + case a.Td, a.Th: + p.parseImpliedToken(StartTagToken, a.Tr, a.Tr.String()) + return false + case a.Caption, a.Col, a.Colgroup, a.Tbody, a.Tfoot, a.Thead: + if p.popUntil(tableScope, a.Tbody, a.Thead, a.Tfoot) { + p.im = inTableIM + return false + } + // Ignore the token. + return true + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Tbody, a.Tfoot, a.Thead: + if p.elementInScope(tableScope, p.tok.DataAtom) { + p.clearStackToContext(tableBodyScope) + p.oe.pop() + p.im = inTableIM + } + return true + case a.Table: + if p.popUntil(tableScope, a.Tbody, a.Thead, a.Tfoot) { + p.im = inTableIM + return false + } + // Ignore the token. + return true + case a.Body, a.Caption, a.Col, a.Colgroup, a.Html, a.Td, a.Th, a.Tr: + // Ignore the token. + return true + } + case CommentToken: + p.addChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + return true + } + + return inTableIM(p) +} + +// Section 12.2.6.4.14. +func inRowIM(p *parser) bool { + switch p.tok.Type { + case StartTagToken: + switch p.tok.DataAtom { + case a.Td, a.Th: + p.clearStackToContext(tableRowScope) + p.addElement() + p.afe = append(p.afe, &scopeMarker) + p.im = inCellIM + return true + case a.Caption, a.Col, a.Colgroup, a.Tbody, a.Tfoot, a.Thead, a.Tr: + if p.popUntil(tableScope, a.Tr) { + p.im = inTableBodyIM + return false + } + // Ignore the token. + return true + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Tr: + if p.popUntil(tableScope, a.Tr) { + p.im = inTableBodyIM + return true + } + // Ignore the token. + return true + case a.Table: + if p.popUntil(tableScope, a.Tr) { + p.im = inTableBodyIM + return false + } + // Ignore the token. + return true + case a.Tbody, a.Tfoot, a.Thead: + if p.elementInScope(tableScope, p.tok.DataAtom) { + p.parseImpliedToken(EndTagToken, a.Tr, a.Tr.String()) + return false + } + // Ignore the token. + return true + case a.Body, a.Caption, a.Col, a.Colgroup, a.Html, a.Td, a.Th: + // Ignore the token. + return true + } + } + + return inTableIM(p) +} + +// Section 12.2.6.4.15. +func inCellIM(p *parser) bool { + switch p.tok.Type { + case StartTagToken: + switch p.tok.DataAtom { + case a.Caption, a.Col, a.Colgroup, a.Tbody, a.Td, a.Tfoot, a.Th, a.Thead, a.Tr: + if p.popUntil(tableScope, a.Td, a.Th) { + // Close the cell and reprocess. + p.clearActiveFormattingElements() + p.im = inRowIM + return false + } + // Ignore the token. + return true + case a.Select: + p.reconstructActiveFormattingElements() + p.addElement() + p.framesetOK = false + p.im = inSelectInTableIM + return true + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Td, a.Th: + if !p.popUntil(tableScope, p.tok.DataAtom) { + // Ignore the token. + return true + } + p.clearActiveFormattingElements() + p.im = inRowIM + return true + case a.Body, a.Caption, a.Col, a.Colgroup, a.Html: + // Ignore the token. + return true + case a.Table, a.Tbody, a.Tfoot, a.Thead, a.Tr: + if !p.elementInScope(tableScope, p.tok.DataAtom) { + // Ignore the token. + return true + } + // Close the cell and reprocess. + if p.popUntil(tableScope, a.Td, a.Th) { + p.clearActiveFormattingElements() + } + p.im = inRowIM + return false + } + } + return inBodyIM(p) +} + +// Section 12.2.6.4.16. +func inSelectIM(p *parser) bool { + switch p.tok.Type { + case TextToken: + p.addText(strings.Replace(p.tok.Data, "\x00", "", -1)) + case StartTagToken: + switch p.tok.DataAtom { + case a.Html: + return inBodyIM(p) + case a.Option: + if p.top().DataAtom == a.Option { + p.oe.pop() + } + p.addElement() + case a.Optgroup: + if p.top().DataAtom == a.Option { + p.oe.pop() + } + if p.top().DataAtom == a.Optgroup { + p.oe.pop() + } + p.addElement() + case a.Select: + if !p.popUntil(selectScope, a.Select) { + // Ignore the token. + return true + } + p.resetInsertionMode() + case a.Input, a.Keygen, a.Textarea: + if p.elementInScope(selectScope, a.Select) { + p.parseImpliedToken(EndTagToken, a.Select, a.Select.String()) + return false + } + // In order to properly ignore <textarea>, we need to change the tokenizer mode. + p.tokenizer.NextIsNotRawText() + // Ignore the token. + return true + case a.Script, a.Template: + return inHeadIM(p) + case a.Iframe, a.Noembed, a.Noframes, a.Noscript, a.Plaintext, a.Style, a.Title, a.Xmp: + // Don't let the tokenizer go into raw text mode when there are raw tags + // to be ignored. These tags should be ignored from the tokenizer + // properly. + p.tokenizer.NextIsNotRawText() + // Ignore the token. + return true + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Option: + if p.top().DataAtom == a.Option { + p.oe.pop() + } + case a.Optgroup: + i := len(p.oe) - 1 + if p.oe[i].DataAtom == a.Option { + i-- + } + if p.oe[i].DataAtom == a.Optgroup { + p.oe = p.oe[:i] + } + case a.Select: + if !p.popUntil(selectScope, a.Select) { + // Ignore the token. + return true + } + p.resetInsertionMode() + case a.Template: + return inHeadIM(p) + } + case CommentToken: + p.addChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + case DoctypeToken: + // Ignore the token. + return true + case ErrorToken: + return inBodyIM(p) + } + + return true +} + +// Section 12.2.6.4.17. +func inSelectInTableIM(p *parser) bool { + switch p.tok.Type { + case StartTagToken, EndTagToken: + switch p.tok.DataAtom { + case a.Caption, a.Table, a.Tbody, a.Tfoot, a.Thead, a.Tr, a.Td, a.Th: + if p.tok.Type == EndTagToken && !p.elementInScope(tableScope, p.tok.DataAtom) { + // Ignore the token. + return true + } + // This is like p.popUntil(selectScope, a.Select), but it also + // matches <math select>, not just <select>. Matching the MathML + // tag is arguably incorrect (conceptually), but it mimics what + // Chromium does. + for i := len(p.oe) - 1; i >= 0; i-- { + if n := p.oe[i]; n.DataAtom == a.Select { + p.oe = p.oe[:i] + break + } + } + p.resetInsertionMode() + return false + } + } + return inSelectIM(p) +} + +// Section 12.2.6.4.18. +func inTemplateIM(p *parser) bool { + switch p.tok.Type { + case TextToken, CommentToken, DoctypeToken: + return inBodyIM(p) + case StartTagToken: + switch p.tok.DataAtom { + case a.Base, a.Basefont, a.Bgsound, a.Link, a.Meta, a.Noframes, a.Script, a.Style, a.Template, a.Title: + return inHeadIM(p) + case a.Caption, a.Colgroup, a.Tbody, a.Tfoot, a.Thead: + p.templateStack.pop() + p.templateStack = append(p.templateStack, inTableIM) + p.im = inTableIM + return false + case a.Col: + p.templateStack.pop() + p.templateStack = append(p.templateStack, inColumnGroupIM) + p.im = inColumnGroupIM + return false + case a.Tr: + p.templateStack.pop() + p.templateStack = append(p.templateStack, inTableBodyIM) + p.im = inTableBodyIM + return false + case a.Td, a.Th: + p.templateStack.pop() + p.templateStack = append(p.templateStack, inRowIM) + p.im = inRowIM + return false + default: + p.templateStack.pop() + p.templateStack = append(p.templateStack, inBodyIM) + p.im = inBodyIM + return false + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Template: + return inHeadIM(p) + default: + // Ignore the token. + return true + } + case ErrorToken: + if !p.oe.contains(a.Template) { + // Ignore the token. + return true + } + // TODO: remove this divergence from the HTML5 spec. + // + // See https://bugs.chromium.org/p/chromium/issues/detail?id=829668 + p.generateImpliedEndTags() + for i := len(p.oe) - 1; i >= 0; i-- { + if n := p.oe[i]; n.Namespace == "" && n.DataAtom == a.Template { + p.oe = p.oe[:i] + break + } + } + p.clearActiveFormattingElements() + p.templateStack.pop() + p.resetInsertionMode() + return false + } + return false +} + +// Section 12.2.6.4.19. +func afterBodyIM(p *parser) bool { + switch p.tok.Type { + case ErrorToken: + // Stop parsing. + return true + case TextToken: + s := strings.TrimLeft(p.tok.Data, whitespace) + if len(s) == 0 { + // It was all whitespace. + return inBodyIM(p) + } + case StartTagToken: + if p.tok.DataAtom == a.Html { + return inBodyIM(p) + } + case EndTagToken: + if p.tok.DataAtom == a.Html { + if !p.fragment { + p.im = afterAfterBodyIM + } + return true + } + case CommentToken: + // The comment is attached to the <html> element. + if len(p.oe) < 1 || p.oe[0].DataAtom != a.Html { + panic("html: bad parser state: <html> element not found, in the after-body insertion mode") + } + p.oe[0].AppendChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + return true + } + p.im = inBodyIM + return false +} + +// Section 12.2.6.4.20. +func inFramesetIM(p *parser) bool { + switch p.tok.Type { + case CommentToken: + p.addChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + case TextToken: + // Ignore all text but whitespace. + s := strings.Map(func(c rune) rune { + switch c { + case ' ', '\t', '\n', '\f', '\r': + return c + } + return -1 + }, p.tok.Data) + if s != "" { + p.addText(s) + } + case StartTagToken: + switch p.tok.DataAtom { + case a.Html: + return inBodyIM(p) + case a.Frameset: + p.addElement() + case a.Frame: + p.addElement() + p.oe.pop() + p.acknowledgeSelfClosingTag() + case a.Noframes: + return inHeadIM(p) + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Frameset: + if p.oe.top().DataAtom != a.Html { + p.oe.pop() + if p.oe.top().DataAtom != a.Frameset { + p.im = afterFramesetIM + return true + } + } + } + default: + // Ignore the token. + } + return true +} + +// Section 12.2.6.4.21. +func afterFramesetIM(p *parser) bool { + switch p.tok.Type { + case CommentToken: + p.addChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + case TextToken: + // Ignore all text but whitespace. + s := strings.Map(func(c rune) rune { + switch c { + case ' ', '\t', '\n', '\f', '\r': + return c + } + return -1 + }, p.tok.Data) + if s != "" { + p.addText(s) + } + case StartTagToken: + switch p.tok.DataAtom { + case a.Html: + return inBodyIM(p) + case a.Noframes: + return inHeadIM(p) + } + case EndTagToken: + switch p.tok.DataAtom { + case a.Html: + p.im = afterAfterFramesetIM + return true + } + default: + // Ignore the token. + } + return true +} + +// Section 12.2.6.4.22. +func afterAfterBodyIM(p *parser) bool { + switch p.tok.Type { + case ErrorToken: + // Stop parsing. + return true + case TextToken: + s := strings.TrimLeft(p.tok.Data, whitespace) + if len(s) == 0 { + // It was all whitespace. + return inBodyIM(p) + } + case StartTagToken: + if p.tok.DataAtom == a.Html { + return inBodyIM(p) + } + case CommentToken: + p.doc.AppendChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + return true + case DoctypeToken: + return inBodyIM(p) + } + p.im = inBodyIM + return false +} + +// Section 12.2.6.4.23. +func afterAfterFramesetIM(p *parser) bool { + switch p.tok.Type { + case CommentToken: + p.doc.AppendChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + case TextToken: + // Ignore all text but whitespace. + s := strings.Map(func(c rune) rune { + switch c { + case ' ', '\t', '\n', '\f', '\r': + return c + } + return -1 + }, p.tok.Data) + if s != "" { + p.tok.Data = s + return inBodyIM(p) + } + case StartTagToken: + switch p.tok.DataAtom { + case a.Html: + return inBodyIM(p) + case a.Noframes: + return inHeadIM(p) + } + case DoctypeToken: + return inBodyIM(p) + default: + // Ignore the token. + } + return true +} + +func ignoreTheRemainingTokens(p *parser) bool { + return true +} + +const whitespaceOrNUL = whitespace + "\x00" + +// Section 12.2.6.5 +func parseForeignContent(p *parser) bool { + switch p.tok.Type { + case TextToken: + if p.framesetOK { + p.framesetOK = strings.TrimLeft(p.tok.Data, whitespaceOrNUL) == "" + } + p.tok.Data = strings.Replace(p.tok.Data, "\x00", "\ufffd", -1) + p.addText(p.tok.Data) + case CommentToken: + p.addChild(&Node{ + Type: CommentNode, + Data: p.tok.Data, + }) + case StartTagToken: + if !p.fragment { + b := breakout[p.tok.Data] + if p.tok.DataAtom == a.Font { + loop: + for _, attr := range p.tok.Attr { + switch attr.Key { + case "color", "face", "size": + b = true + break loop + } + } + } + if b { + for i := len(p.oe) - 1; i >= 0; i-- { + n := p.oe[i] + if n.Namespace == "" || htmlIntegrationPoint(n) || mathMLTextIntegrationPoint(n) { + p.oe = p.oe[:i+1] + break + } + } + return false + } + } + current := p.adjustedCurrentNode() + switch current.Namespace { + case "math": + adjustAttributeNames(p.tok.Attr, mathMLAttributeAdjustments) + case "svg": + // Adjust SVG tag names. The tokenizer lower-cases tag names, but + // SVG wants e.g. "foreignObject" with a capital second "O". + if x := svgTagNameAdjustments[p.tok.Data]; x != "" { + p.tok.DataAtom = a.Lookup([]byte(x)) + p.tok.Data = x + } + adjustAttributeNames(p.tok.Attr, svgAttributeAdjustments) + default: + panic("html: bad parser state: unexpected namespace") + } + adjustForeignAttributes(p.tok.Attr) + namespace := current.Namespace + p.addElement() + p.top().Namespace = namespace + if namespace != "" { + // Don't let the tokenizer go into raw text mode in foreign content + // (e.g. in an SVG <title> tag). + p.tokenizer.NextIsNotRawText() + } + if p.hasSelfClosingToken { + p.oe.pop() + p.acknowledgeSelfClosingTag() + } + case EndTagToken: + for i := len(p.oe) - 1; i >= 0; i-- { + if p.oe[i].Namespace == "" { + return p.im(p) + } + if strings.EqualFold(p.oe[i].Data, p.tok.Data) { + p.oe = p.oe[:i] + break + } + } + return true + default: + // Ignore the token. + } + return true +} + +// Section 12.2.4.2. +func (p *parser) adjustedCurrentNode() *Node { + if len(p.oe) == 1 && p.fragment && p.context != nil { + return p.context + } + return p.oe.top() +} + +// Section 12.2.6. +func (p *parser) inForeignContent() bool { + if len(p.oe) == 0 { + return false + } + n := p.adjustedCurrentNode() + if n.Namespace == "" { + return false + } + if mathMLTextIntegrationPoint(n) { + if p.tok.Type == StartTagToken && p.tok.DataAtom != a.Mglyph && p.tok.DataAtom != a.Malignmark { + return false + } + if p.tok.Type == TextToken { + return false + } + } + if n.Namespace == "math" && n.DataAtom == a.AnnotationXml && p.tok.Type == StartTagToken && p.tok.DataAtom == a.Svg { + return false + } + if htmlIntegrationPoint(n) && (p.tok.Type == StartTagToken || p.tok.Type == TextToken) { + return false + } + if p.tok.Type == ErrorToken { + return false + } + return true +} + +// parseImpliedToken parses a token as though it had appeared in the parser's +// input. +func (p *parser) parseImpliedToken(t TokenType, dataAtom a.Atom, data string) { + realToken, selfClosing := p.tok, p.hasSelfClosingToken + p.tok = Token{ + Type: t, + DataAtom: dataAtom, + Data: data, + } + p.hasSelfClosingToken = false + p.parseCurrentToken() + p.tok, p.hasSelfClosingToken = realToken, selfClosing +} + +// parseCurrentToken runs the current token through the parsing routines +// until it is consumed. +func (p *parser) parseCurrentToken() { + if p.tok.Type == SelfClosingTagToken { + p.hasSelfClosingToken = true + p.tok.Type = StartTagToken + } + + consumed := false + for !consumed { + if p.inForeignContent() { + consumed = parseForeignContent(p) + } else { + consumed = p.im(p) + } + } + + if p.hasSelfClosingToken { + // This is a parse error, but ignore it. + p.hasSelfClosingToken = false + } +} + +func (p *parser) parse() error { + // Iterate until EOF. Any other error will cause an early return. + var err error + for err != io.EOF { + // CDATA sections are allowed only in foreign content. + n := p.oe.top() + p.tokenizer.AllowCDATA(n != nil && n.Namespace != "") + // Read and parse the next token. + p.tokenizer.Next() + p.tok = p.tokenizer.Token() + if p.tok.Type == ErrorToken { + err = p.tokenizer.Err() + if err != nil && err != io.EOF { + return err + } + } + p.parseCurrentToken() + } + return nil +} + +// Parse returns the parse tree for the HTML from the given Reader. +// +// It implements the HTML5 parsing algorithm +// (https://html.spec.whatwg.org/multipage/syntax.html#tree-construction), +// which is very complicated. The resultant tree can contain implicitly created +// nodes that have no explicit <tag> listed in r's data, and nodes' parents can +// differ from the nesting implied by a naive processing of start and end +// <tag>s. Conversely, explicit <tag>s in r's data can be silently dropped, +// with no corresponding node in the resulting tree. +// +// The input is assumed to be UTF-8 encoded. +func Parse(r io.Reader) (*Node, error) { + return ParseWithOptions(r) +} + +// ParseFragment parses a fragment of HTML and returns the nodes that were +// found. If the fragment is the InnerHTML for an existing element, pass that +// element in context. +// +// It has the same intricacies as Parse. +func ParseFragment(r io.Reader, context *Node) ([]*Node, error) { + return ParseFragmentWithOptions(r, context) +} + +// ParseOption configures a parser. +type ParseOption func(p *parser) + +// ParseOptionEnableScripting configures the scripting flag. +// https://html.spec.whatwg.org/multipage/webappapis.html#enabling-and-disabling-scripting +// +// By default, scripting is enabled. +func ParseOptionEnableScripting(enable bool) ParseOption { + return func(p *parser) { + p.scripting = enable + } +} + +// ParseWithOptions is like Parse, with options. +func ParseWithOptions(r io.Reader, opts ...ParseOption) (*Node, error) { + p := &parser{ + tokenizer: NewTokenizer(r), + doc: &Node{ + Type: DocumentNode, + }, + scripting: true, + framesetOK: true, + im: initialIM, + } + + for _, f := range opts { + f(p) + } + + if err := p.parse(); err != nil { + return nil, err + } + return p.doc, nil +} + +// ParseFragmentWithOptions is like ParseFragment, with options. +func ParseFragmentWithOptions(r io.Reader, context *Node, opts ...ParseOption) ([]*Node, error) { + contextTag := "" + if context != nil { + if context.Type != ElementNode { + return nil, errors.New("html: ParseFragment of non-element Node") + } + // The next check isn't just context.DataAtom.String() == context.Data because + // it is valid to pass an element whose tag isn't a known atom. For example, + // DataAtom == 0 and Data = "tagfromthefuture" is perfectly consistent. + if context.DataAtom != a.Lookup([]byte(context.Data)) { + return nil, fmt.Errorf("html: inconsistent Node: DataAtom=%q, Data=%q", context.DataAtom, context.Data) + } + contextTag = context.DataAtom.String() + } + p := &parser{ + doc: &Node{ + Type: DocumentNode, + }, + scripting: true, + fragment: true, + context: context, + } + if context != nil && context.Namespace != "" { + p.tokenizer = NewTokenizer(r) + } else { + p.tokenizer = NewTokenizerFragment(r, contextTag) + } + + for _, f := range opts { + f(p) + } + + root := &Node{ + Type: ElementNode, + DataAtom: a.Html, + Data: a.Html.String(), + } + p.doc.AppendChild(root) + p.oe = nodeStack{root} + if context != nil && context.DataAtom == a.Template { + p.templateStack = append(p.templateStack, inTemplateIM) + } + p.resetInsertionMode() + + for n := context; n != nil; n = n.Parent { + if n.Type == ElementNode && n.DataAtom == a.Form { + p.form = n + break + } + } + + if err := p.parse(); err != nil { + return nil, err + } + + parent := p.doc + if context != nil { + parent = root + } + + var result []*Node + for c := parent.FirstChild; c != nil; { + next := c.NextSibling + parent.RemoveChild(c) + result = append(result, c) + c = next + } + return result, nil +} |
