Parse HTML to DOM

parseHTMLtoDOM.js

function parseHTMLtoDOM (html) {
    var regexTags = /(<[a-zA-Z1-9]+(?:\s+[a-zA-Z-]+(?:=(?:".*?"|'.*?'))?)*\s*\/?>|<\/[a-zA-Z1-9]+>)/gm, // Match tags (opening incl. attributes & closing)
        regexAttr = /(?:\s+([a-zA-Z-]+)(?:=(?:"(.*?)"|'(.*?)'))?)/gm; // Match attributes
    
    var singletons = ['area','base','br','col','command','embed','hr','img','input','keygen','link','meta','param','source','track','wbr']; // HTML 5 - 6/9/2016
    
    html = html.replace(/&nbsp;/g, '\u00A0'); // TODO: add more encoding fixes
    
    var parts = html.split(regexTags), fragment = document.createDocumentFragment(), lastElement = fragment;
    for (var i=0, il=parts.length; i<il; i++) {
        if (parts[i].length > 0) {
            var tag = parts[i].match(/^<(\/)?([a-zA-Z1-9]+)/);
            if (tag && tag.length > 0) { // Process tag
                if (tag[1] === undefined) { // Opening tag
                    var element = document.createElement(tag[2]); // Create tag
    
                    while ((attributes = regexAttr.exec(parts[i])) !== null) { // Loop attributes
                        var attribute = document.createAttribute(attributes[1]);
                        if (attributes[2] !== undefined) {
                            attribute.value = attributes[2]; // Set attribute value
                        }
                        element.setAttributeNode(attribute); // Add attribute
                    }
                    lastElement.appendChild(element); // Append our element
    
                    if (singletons.indexOf(tag[2]) === -1) { //Singletons can't have child elements
                        lastElement = element; // Set last element as current element
                    }
                } else { // Closing tag
                    lastElement = lastElement.parentNode; // Closing tag means we need to go 1 level up again
                }
            } else {
                lastElement.appendChild(document.createTextNode(parts[i])); // Append content to the last element
            }
        }
    }
    
    return fragment;
}