htmlparser2/lib/DefaultHandler.js

var ElementType = require("./ElementType.js");

function DefaultHandler(callback, options){
	this.dom = [];
	this._done = false;
	this._inSpecialTag = false;
	this._tagStack = [];
	if(options) this._options = options; //otherwise, the prototype is used
	if(callback) this._callback = callback;
}

//default options
DefaultHandler.prototype._options = {
	ignoreWhitespace: false //Keep whitespace-only text nodes
};

//Resets the handler back to starting state
DefaultHandler.prototype.onreset = DefaultHandler;

//Signals the handler that parsing is done
DefaultHandler.prototype.onend = function(){
	if(this._done) return;
	this._done = true;
	this._handleCallback(null);
};

DefaultHandler.prototype.onerror = function(error){
	if(typeof this._callback === "function"){
		return this._callback(error, this.dom);
	} else {
		if(error) throw error;
	}
};

DefaultHandler.prototype._handleCallback = DefaultHandler.prototype.onerror;

DefaultHandler.prototype.onclosetag = function(name){
	this._tagStack.pop();
};

DefaultHandler.prototype._addDomElement = function(element){
	var lastChild,
		lastTag = this._tagStack[this._tagStack.length - 1];
	
	if(lastTag){ //There are parent elements
		if(!lastTag.children){
			lastTag.children = [element];
			return;
		}
		lastChild = lastTag.children[lastTag.children.length - 1];
		if(this._inSpecialTag && element.type === ElementType.Text && lastChild.type === ElementType.Text){
			lastChild.data += element.data;
		} else {
			lastTag.children.push(element);
		}
	}
	else {
		this.dom.push(element);
	}
};

DefaultHandler.prototype.onopentag = function(name, attribs, type){
	if(type === ElementType.Script || type === ElementType.Style){
		this._inSpecialTag = true;
	}
	var element = {
		type: type,
		name: name,
		attribs: attribs
	};
	this._addDomElement(element);
	this._tagStack.push(element);
};

DefaultHandler.prototype.ontext = function(data){
	if(this._options.ignoreWhitespace && data.trim() === "") return;
	this._addDomElement({
		data: data,
		type: ElementType.Text
	});
};

DefaultHandler.prototype.oncomment = function(data){
	var lastTag = this._tagStack[this._tagStack.length - 1];
	var lastChild = lastTag && lastTag.children && lastTag.children[lastTag.children.length - 1];
	
	var element;
	if(!lastChild || lastChild.type !== ElementType.Comment){
		element = {
			data: data,
			type: ElementType.Comment
		};
		if(!lastTag){
			return this.dom.push(element);
		} else if(!lastChild){
			lastTag.children = [element];
		} else {
			if(lastChild.type !== ElementType.Comment){
				lastTag.children.push(element);
			}
		}
	} else {
		lastChild.data += data;
	}
};

DefaultHandler.prototype.onprocessinginstruction = function(name, data){
	this._addDomElement({
		name: name,
		data: data,
		type: ElementType.Directive
	});
};

module.exports = DefaultHandler;