function SaxParser(settings, schema) {
		var self = this;

		function noop() {}

		settings = settings || {};
		self.schema = schema = schema || new Schema();

		if (settings.fix_self_closing !== false) {
			settings.fix_self_closing = true;
		}

		// Add handler functions from settings and setup default handlers
		each('comment cdata text start end pi doctype'.split(' '), function(name) {
			if (name) {
				self[name] = settings[name] || noop;
			}
		});

		/**
		 * Parses the specified HTML string and executes the callbacks for each item it finds.
		 *
		 * @example
		 * new SaxParser({...}).parse('<b>text</b>');
		 * @method parse
		 * @param {String} html Html string to sax parse.
		 */
		self.parse = function(html) {
			var self = this, matches, index = 0, value, endRegExp, stack = [], attrList, i, text, name;
			var isInternalElement, removeInternalElements, shortEndedElements, fillAttrsMap, isShortEnded;
			var validate, elementRule, isValidElement, attr, attribsValue, validAttributesMap, validAttributePatterns;
			var attributesRequired, attributesDefault, attributesForced;
			var anyAttributesRequired, selfClosing, tokenRegExp, attrRegExp, specialElements, attrValue, idCount = 0;
			var decode = Entities.decode, fixSelfClosing, filteredUrlAttrs = Tools.makeMap('src,href,data,background,formaction,poster');
			var scriptUriRegExp = /((java|vb)script|mhtml):/i, dataUriRegExp = /^data:/i;

			function processEndTag(name) {
				var pos, i;

				// Find position of parent of the same type
				pos = stack.length;
				while (pos--) {
					if (stack[pos].name === name) {
						break;
					}
				}

				// Found parent
				if (pos >= 0) {
					// Close all the open elements
					for (i = stack.length - 1; i >= pos; i--) {
						name = stack[i];

						if (name.valid) {
							self.end(name.name);
						}
					}

					// Remove the open elements from the stack
					stack.length = pos;
				}
			}

			function parseAttribute(match, name, value, val2, val3) {
				var attrRule, i, trimRegExp = /[\s\u0000-\u001F]+/g;

				name = name.toLowerCase();
				value = name in fillAttrsMap ? name : decode(value || val2 || val3 || ''); // Handle boolean attribute than value attribute

				// Validate name and value pass through all data- attributes
				if (validate && !isInternalElement && name.indexOf('data-') !== 0) {
					attrRule = validAttributesMap[name];

					// Find rule by pattern matching
					if (!attrRule && validAttributePatterns) {
						i = validAttributePatterns.length;
						while (i--) {
							attrRule = validAttributePatterns[i];
							if (attrRule.pattern.test(name)) {
								break;
							}
						}

						// No rule matched
						if (i === -1) {
							attrRule = null;
						}
					}

					// No attribute rule found
					if (!attrRule) {
						return;
					}

					// Validate value
					if (attrRule.validValues && !(value in attrRule.validValues)) {
						return;
					}
				}

				// Block any javascript: urls or non image data uris
				if (filteredUrlAttrs[name] && !settings.allow_script_urls) {
					var uri = value.replace(trimRegExp, '');

					try {
						// Might throw malformed URI sequence
						uri = decodeURIComponent(uri);
					} catch (ex) {
						// Fallback to non UTF-8 decoder
						uri = unescape(uri);
					}

					if (scriptUriRegExp.test(uri)) {
						return;
					}

					if (!settings.allow_html_data_urls && dataUriRegExp.test(uri) && !/^data:image\//i.test(uri)) {
						return;
					}
				}

				// Add attribute to list and map
				attrList.map[name] = value;
				attrList.push({
					name: name,
					value: value
				});
			}

			// Precompile RegExps and map objects
			tokenRegExp = new RegExp('<(?:' +
				'(?:!--([\\w\\W]*?)-->)|' + // Comment
				'(?:!\\[CDATA\\[([\\w\\W]*?)\\]\\]>)|' + // CDATA
				'(?:!DOCTYPE([\\w\\W]*?)>)|' + // DOCTYPE
				'(?:\\?([^\\s\\/<>]+) ?([\\w\\W]*?)[?/]>)|' + // PI
				'(?:\\/([^>]+)>)|' + // End element
				'(?:([A-Za-z0-9\\-_\\:\\.]+)((?:\\s+[^"\'>]+(?:(?:"[^"]*")|(?:\'[^\']*\')|[^>]*))*|\\/|\\s+)>)' + // Start element
			')', 'g');

			attrRegExp = /([\w:\-]+)(?:\s*=\s*(?:(?:\"((?:[^\"])*)\")|(?:\'((?:[^\'])*)\')|([^>\s]+)))?/g;

			// Setup lookup tables for empty elements and boolean attributes
			shortEndedElements = schema.getShortEndedElements();
			selfClosing = settings.self_closing_elements || schema.getSelfClosingElements();
			fillAttrsMap = schema.getBoolAttrs();
			validate = settings.validate;
			removeInternalElements = settings.remove_internals;
			fixSelfClosing = settings.fix_self_closing;
			specialElements = schema.getSpecialElements();

			while ((matches = tokenRegExp.exec(html))) {
				// Text
				if (index < matches.index) {
					self.text(decode(html.substr(index, matches.index - index)));
				}

				if ((value = matches[6])) { // End element
					value = value.toLowerCase();

					// IE will add a ":" in front of elements it doesn't understand like custom elements or HTML5 elements
					if (value.charAt(0) === ':') {
						value = value.substr(1);
					}

					processEndTag(value);
				} else if ((value = matches[7])) { // Start element
					value = value.toLowerCase();

					// IE will add a ":" in front of elements it doesn't understand like custom elements or HTML5 elements
					if (value.charAt(0) === ':') {
						value = value.substr(1);
					}

					isShortEnded = value in shortEndedElements;

					// Is self closing tag for example an <li> after an open <li>
					if (fixSelfClosing && selfClosing[value] && stack.length > 0 && stack[stack.length - 1].name === value) {
						processEndTag(value);
					}

					// Validate element
					if (!validate || (elementRule = schema.getElementRule(value))) {
						isValidElement = true;

						// Grab attributes map and patters when validation is enabled
						if (validate) {
							validAttributesMap = elementRule.attributes;
							validAttributePatterns = elementRule.attributePatterns;
						}

						// Parse attributes
						if ((attribsValue = matches[8])) {
							isInternalElement = attribsValue.indexOf('data-mce-type') !== -1; // Check if the element is an internal element

							// If the element has internal attributes then remove it if we are told to do so
							if (isInternalElement && removeInternalElements) {
								isValidElement = false;
							}

							attrList = [];
							attrList.map = {};

							attribsValue.replace(attrRegExp, parseAttribute);
						} else {
							attrList = [];
							attrList.map = {};
						}

						// Process attributes if validation is enabled
						if (validate && !isInternalElement) {
							attributesRequired = elementRule.attributesRequired;
							attributesDefault = elementRule.attributesDefault;
							attributesForced = elementRule.attributesForced;
							anyAttributesRequired = elementRule.removeEmptyAttrs;

							// Check if any attribute exists
							if (anyAttributesRequired && !attrList.length) {
								isValidElement = false;
							}

							// Handle forced attributes
							if (attributesForced) {
								i = attributesForced.length;
								while (i--) {
									attr = attributesForced[i];
									name = attr.name;
									attrValue = attr.value;

									if (attrValue === '{$uid}') {
										attrValue = 'mce_' + idCount++;
									}

									attrList.map[name] = attrValue;
									attrList.push({name: name, value: attrValue});
								}
							}

							// Handle default attributes
							if (attributesDefault) {
								i = attributesDefault.length;
								while (i--) {
									attr = attributesDefault[i];
									name = attr.name;

									if (!(name in attrList.map)) {
										attrValue = attr.value;

										if (attrValue === '{$uid}') {
											attrValue = 'mce_' + idCount++;
										}

										attrList.map[name] = attrValue;
										attrList.push({name: name, value: attrValue});
									}
								}
							}

							// Handle required attributes
							if (attributesRequired) {
								i = attributesRequired.length;
								while (i--) {
									if (attributesRequired[i] in attrList.map) {
										break;
									}
								}

								// None of the required attributes where found
								if (i === -1) {
									isValidElement = false;
								}
							}

							// Invalidate element if it's marked as bogus
							if ((attr = attrList.map['data-mce-bogus'])) {
								if (attr === 'all') {
									index = findEndTag(schema, html, tokenRegExp.lastIndex);
									tokenRegExp.lastIndex = index;
									continue;
								}

								isValidElement = false;
							}
						}

						if (isValidElement) {
							self.start(value, attrList, isShortEnded);
						}
					} else {
						isValidElement = false;
					}

					// Treat script, noscript and style a bit different since they may include code that looks like elements
					if ((endRegExp = specialElements[value])) {
						endRegExp.lastIndex = index = matches.index + matches[0].length;

						if ((matches = endRegExp.exec(html))) {
							if (isValidElement) {
								text = html.substr(index, matches.index - index);
							}

							index = matches.index + matches[0].length;
						} else {
							text = html.substr(index);
							index = html.length;
						}

						if (isValidElement) {
							if (text.length > 0) {
								self.text(text, true);
							}

							self.end(value);
						}

						tokenRegExp.lastIndex = index;
						continue;
					}

					// Push value on to stack
					if (!isShortEnded) {
						if (!attribsValue || attribsValue.indexOf('/') != attribsValue.length - 1) {
							stack.push({name: value, valid: isValidElement});
						} else if (isValidElement) {
							self.end(value);
						}
					}
				} else if ((value = matches[1])) { // Comment
					// Padd comment value to avoid browsers from parsing invalid comments as HTML
					if (value.charAt(0) === '>') {
						value = ' ' + value;
					}

					if (!settings.allow_conditional_comments && value.substr(0, 3) === '[if') {
						value = ' ' + value;
					}

					self.comment(value);
				} else if ((value = matches[2])) { // CDATA
					self.cdata(value);
				} else if ((value = matches[3])) { // DOCTYPE
					self.doctype(value);
				} else if ((value = matches[4])) { // PI
					self.pi(value, matches[5]);
				}

				index = matches.index + matches[0].length;
			}

			// Text
			if (index < html.length) {
				self.text(decode(html.substr(index)));
			}

			// Close any open elements
			for (i = stack.length - 1; i >= 0; i--) {
				value = stack[i];

				if (value.valid) {
					self.end(value.name);
				}
			}
		};
	}
Constructs a new SaxParser instance.

@constructor
@method SaxParser
@param {Object} settings Name/value collection of settings. comment, cdata, text, start and end are callbacks.
@param {tinymce.html.Schema} schema HTML Schema class to use when parsing.