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483 lines
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JavaScript

'use strict';
const HTML = require('../common/html');
//Aliases
const $ = HTML.TAG_NAMES;
const NS = HTML.NAMESPACES;
//Element utils
//OPTIMIZATION: Integer comparisons are low-cost, so we can use very fast tag name length filters here.
//It's faster than using dictionary.
function isImpliedEndTagRequired(tn) {
switch (tn.length) {
case 1:
return tn === $.P;
case 2:
return tn === $.RB || tn === $.RP || tn === $.RT || tn === $.DD || tn === $.DT || tn === $.LI;
case 3:
return tn === $.RTC;
case 6:
return tn === $.OPTION;
case 8:
return tn === $.OPTGROUP;
}
return false;
}
function isImpliedEndTagRequiredThoroughly(tn) {
switch (tn.length) {
case 1:
return tn === $.P;
case 2:
return (
tn === $.RB ||
tn === $.RP ||
tn === $.RT ||
tn === $.DD ||
tn === $.DT ||
tn === $.LI ||
tn === $.TD ||
tn === $.TH ||
tn === $.TR
);
case 3:
return tn === $.RTC;
case 5:
return tn === $.TBODY || tn === $.TFOOT || tn === $.THEAD;
case 6:
return tn === $.OPTION;
case 7:
return tn === $.CAPTION;
case 8:
return tn === $.OPTGROUP || tn === $.COLGROUP;
}
return false;
}
function isScopingElement(tn, ns) {
switch (tn.length) {
case 2:
if (tn === $.TD || tn === $.TH) {
return ns === NS.HTML;
} else if (tn === $.MI || tn === $.MO || tn === $.MN || tn === $.MS) {
return ns === NS.MATHML;
}
break;
case 4:
if (tn === $.HTML) {
return ns === NS.HTML;
} else if (tn === $.DESC) {
return ns === NS.SVG;
}
break;
case 5:
if (tn === $.TABLE) {
return ns === NS.HTML;
} else if (tn === $.MTEXT) {
return ns === NS.MATHML;
} else if (tn === $.TITLE) {
return ns === NS.SVG;
}
break;
case 6:
return (tn === $.APPLET || tn === $.OBJECT) && ns === NS.HTML;
case 7:
return (tn === $.CAPTION || tn === $.MARQUEE) && ns === NS.HTML;
case 8:
return tn === $.TEMPLATE && ns === NS.HTML;
case 13:
return tn === $.FOREIGN_OBJECT && ns === NS.SVG;
case 14:
return tn === $.ANNOTATION_XML && ns === NS.MATHML;
}
return false;
}
//Stack of open elements
class OpenElementStack {
constructor(document, treeAdapter) {
this.stackTop = -1;
this.items = [];
this.current = document;
this.currentTagName = null;
this.currentTmplContent = null;
this.tmplCount = 0;
this.treeAdapter = treeAdapter;
}
//Index of element
_indexOf(element) {
let idx = -1;
for (let i = this.stackTop; i >= 0; i--) {
if (this.items[i] === element) {
idx = i;
break;
}
}
return idx;
}
//Update current element
_isInTemplate() {
return this.currentTagName === $.TEMPLATE && this.treeAdapter.getNamespaceURI(this.current) === NS.HTML;
}
_updateCurrentElement() {
this.current = this.items[this.stackTop];
this.currentTagName = this.current && this.treeAdapter.getTagName(this.current);
this.currentTmplContent = this._isInTemplate() ? this.treeAdapter.getTemplateContent(this.current) : null;
}
//Mutations
push(element) {
this.items[++this.stackTop] = element;
this._updateCurrentElement();
if (this._isInTemplate()) {
this.tmplCount++;
}
}
pop() {
this.stackTop--;
if (this.tmplCount > 0 && this._isInTemplate()) {
this.tmplCount--;
}
this._updateCurrentElement();
}
replace(oldElement, newElement) {
const idx = this._indexOf(oldElement);
this.items[idx] = newElement;
if (idx === this.stackTop) {
this._updateCurrentElement();
}
}
insertAfter(referenceElement, newElement) {
const insertionIdx = this._indexOf(referenceElement) + 1;
this.items.splice(insertionIdx, 0, newElement);
if (insertionIdx === ++this.stackTop) {
this._updateCurrentElement();
}
}
popUntilTagNamePopped(tagName) {
while (this.stackTop > -1) {
const tn = this.currentTagName;
const ns = this.treeAdapter.getNamespaceURI(this.current);
this.pop();
if (tn === tagName && ns === NS.HTML) {
break;
}
}
}
popUntilElementPopped(element) {
while (this.stackTop > -1) {
const poppedElement = this.current;
this.pop();
if (poppedElement === element) {
break;
}
}
}
popUntilNumberedHeaderPopped() {
while (this.stackTop > -1) {
const tn = this.currentTagName;
const ns = this.treeAdapter.getNamespaceURI(this.current);
this.pop();
if (
tn === $.H1 ||
tn === $.H2 ||
tn === $.H3 ||
tn === $.H4 ||
tn === $.H5 ||
(tn === $.H6 && ns === NS.HTML)
) {
break;
}
}
}
popUntilTableCellPopped() {
while (this.stackTop > -1) {
const tn = this.currentTagName;
const ns = this.treeAdapter.getNamespaceURI(this.current);
this.pop();
if (tn === $.TD || (tn === $.TH && ns === NS.HTML)) {
break;
}
}
}
popAllUpToHtmlElement() {
//NOTE: here we assume that root <html> element is always first in the open element stack, so
//we perform this fast stack clean up.
this.stackTop = 0;
this._updateCurrentElement();
}
clearBackToTableContext() {
while (
(this.currentTagName !== $.TABLE && this.currentTagName !== $.TEMPLATE && this.currentTagName !== $.HTML) ||
this.treeAdapter.getNamespaceURI(this.current) !== NS.HTML
) {
this.pop();
}
}
clearBackToTableBodyContext() {
while (
(this.currentTagName !== $.TBODY &&
this.currentTagName !== $.TFOOT &&
this.currentTagName !== $.THEAD &&
this.currentTagName !== $.TEMPLATE &&
this.currentTagName !== $.HTML) ||
this.treeAdapter.getNamespaceURI(this.current) !== NS.HTML
) {
this.pop();
}
}
clearBackToTableRowContext() {
while (
(this.currentTagName !== $.TR && this.currentTagName !== $.TEMPLATE && this.currentTagName !== $.HTML) ||
this.treeAdapter.getNamespaceURI(this.current) !== NS.HTML
) {
this.pop();
}
}
remove(element) {
for (let i = this.stackTop; i >= 0; i--) {
if (this.items[i] === element) {
this.items.splice(i, 1);
this.stackTop--;
this._updateCurrentElement();
break;
}
}
}
//Search
tryPeekProperlyNestedBodyElement() {
//Properly nested <body> element (should be second element in stack).
const element = this.items[1];
return element && this.treeAdapter.getTagName(element) === $.BODY ? element : null;
}
contains(element) {
return this._indexOf(element) > -1;
}
getCommonAncestor(element) {
let elementIdx = this._indexOf(element);
return --elementIdx >= 0 ? this.items[elementIdx] : null;
}
isRootHtmlElementCurrent() {
return this.stackTop === 0 && this.currentTagName === $.HTML;
}
//Element in scope
hasInScope(tagName) {
for (let i = this.stackTop; i >= 0; i--) {
const tn = this.treeAdapter.getTagName(this.items[i]);
const ns = this.treeAdapter.getNamespaceURI(this.items[i]);
if (tn === tagName && ns === NS.HTML) {
return true;
}
if (isScopingElement(tn, ns)) {
return false;
}
}
return true;
}
hasNumberedHeaderInScope() {
for (let i = this.stackTop; i >= 0; i--) {
const tn = this.treeAdapter.getTagName(this.items[i]);
const ns = this.treeAdapter.getNamespaceURI(this.items[i]);
if (
(tn === $.H1 || tn === $.H2 || tn === $.H3 || tn === $.H4 || tn === $.H5 || tn === $.H6) &&
ns === NS.HTML
) {
return true;
}
if (isScopingElement(tn, ns)) {
return false;
}
}
return true;
}
hasInListItemScope(tagName) {
for (let i = this.stackTop; i >= 0; i--) {
const tn = this.treeAdapter.getTagName(this.items[i]);
const ns = this.treeAdapter.getNamespaceURI(this.items[i]);
if (tn === tagName && ns === NS.HTML) {
return true;
}
if (((tn === $.UL || tn === $.OL) && ns === NS.HTML) || isScopingElement(tn, ns)) {
return false;
}
}
return true;
}
hasInButtonScope(tagName) {
for (let i = this.stackTop; i >= 0; i--) {
const tn = this.treeAdapter.getTagName(this.items[i]);
const ns = this.treeAdapter.getNamespaceURI(this.items[i]);
if (tn === tagName && ns === NS.HTML) {
return true;
}
if ((tn === $.BUTTON && ns === NS.HTML) || isScopingElement(tn, ns)) {
return false;
}
}
return true;
}
hasInTableScope(tagName) {
for (let i = this.stackTop; i >= 0; i--) {
const tn = this.treeAdapter.getTagName(this.items[i]);
const ns = this.treeAdapter.getNamespaceURI(this.items[i]);
if (ns !== NS.HTML) {
continue;
}
if (tn === tagName) {
return true;
}
if (tn === $.TABLE || tn === $.TEMPLATE || tn === $.HTML) {
return false;
}
}
return true;
}
hasTableBodyContextInTableScope() {
for (let i = this.stackTop; i >= 0; i--) {
const tn = this.treeAdapter.getTagName(this.items[i]);
const ns = this.treeAdapter.getNamespaceURI(this.items[i]);
if (ns !== NS.HTML) {
continue;
}
if (tn === $.TBODY || tn === $.THEAD || tn === $.TFOOT) {
return true;
}
if (tn === $.TABLE || tn === $.HTML) {
return false;
}
}
return true;
}
hasInSelectScope(tagName) {
for (let i = this.stackTop; i >= 0; i--) {
const tn = this.treeAdapter.getTagName(this.items[i]);
const ns = this.treeAdapter.getNamespaceURI(this.items[i]);
if (ns !== NS.HTML) {
continue;
}
if (tn === tagName) {
return true;
}
if (tn !== $.OPTION && tn !== $.OPTGROUP) {
return false;
}
}
return true;
}
//Implied end tags
generateImpliedEndTags() {
while (isImpliedEndTagRequired(this.currentTagName)) {
this.pop();
}
}
generateImpliedEndTagsThoroughly() {
while (isImpliedEndTagRequiredThoroughly(this.currentTagName)) {
this.pop();
}
}
generateImpliedEndTagsWithExclusion(exclusionTagName) {
while (isImpliedEndTagRequired(this.currentTagName) && this.currentTagName !== exclusionTagName) {
this.pop();
}
}
}
module.exports = OpenElementStack;