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'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;
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