// Based on https://gist.github.com/1129031 By Eli Grey, http://eligrey.com - Public domain.
// DO NOT use https://developer.mozilla.org/en-US/docs/Web/API/DOMParser example polyfill
// as it does not work with earlier versions of Chrome
(function(DOMParser) {
'use strict';
var DOMParser_proto;
var real_parseFromString;
var textHTML; // Flag for text/html support
var textXML; // Flag for text/xml support
var htmlElInnerHTML; // Flag for support for setting html element's innerHTML
// Stop here if DOMParser not defined
if (!DOMParser) {
return;
}
// Firefox, Opera and IE throw errors on unsupported types
try {
// WebKit returns null on unsupported types
textHTML = !!(new DOMParser()).parseFromString('', 'text/html');
} catch (er) {
textHTML = false;
}
// If text/html supported, don't need to do anything.
if (textHTML) {
return;
}
// Next try setting innerHTML of a created document
// IE 9 and lower will throw an error (can't set innerHTML of its HTML element)
try {
var doc = document.implementation.createHTMLDocument('');
doc.documentElement.innerHTML = '';
htmlElInnerHTML = true;
} catch (er) {
htmlElInnerHTML = false;
}
// If if that failed, try text/xml
if (!htmlElInnerHTML) {
try {
textXML = !!(new DOMParser()).parseFromString('', 'text/xml');
} catch (er) {
textHTML = false;
}
}
// Mess with DOMParser.prototype (less than optimal...) if one of the above worked
// Assume can write to the prototype, if not, make this a stand alone function
if (DOMParser.prototype && (htmlElInnerHTML || textXML)) {
DOMParser_proto = DOMParser.prototype;
real_parseFromString = DOMParser_proto.parseFromString;
DOMParser_proto.parseFromString = function (markup, type) {
// Only do this if type is text/html
if (/^\s*text\/html\s*(?:;|$)/i.test(type)) {
var doc, doc_el, first_el;
// Use innerHTML if supported
if (htmlElInnerHTML) {
doc = document.implementation.createHTMLDocument('');
doc_el = doc.documentElement;
doc_el.innerHTML = markup;
first_el = doc_el.firstElementChild;
// Otherwise use XML method
} else if (textXML) {
// Make sure markup is wrapped in HTML tags
// Should probably allow for a DOCTYPE
if (!(/^$/i.test(markup))) {
markup = '' + markup + '<\/html>';
}
doc = (new DOMParser()).parseFromString(markup, 'text/xml');
doc_el = doc.documentElement;
first_el = doc_el.firstElementChild;
}
// Is this an entire document or a fragment?
if (doc_el.childElementCount === 1 && first_el.localName.toLowerCase() === 'html') {
doc.replaceChild(first_el, doc_el);
}
return doc;
// If not text/html, send as-is to host method
} else {
return real_parseFromString.apply(this, arguments);
}
};
}
}(DOMParser));