twitter-expand-url/index.js

expand twitter urls based on API json

var domains = require("./data/domains.json");
var _ = require("lodash");

var expandURL = require("expand-url");

function TwitterExpandURL(){
	this.amount = 0;
	this.done = 0;
}

function _isValid(url){
	if(new RegExp("^(http|https)://t.co/").test(url)){
		if(url.split("co/")[1].length === 10){
			return true;
		}
	}
	return false;
}

function _isShortened(url){
	for(var i = 0;i < domains.length;i++){
		if(new RegExp("^(http|https)://" + domains[i]).test(url)){
			return true;
		}
	}
	return false;
}

function _expand(params, cb){
	params = params || {};
	if(!params.url){
		return cb(new Error("please provide a url to shorten"));
	}
	expandURL.expand(params.url, function(err, original){
		return cb(null, {url: params.url, expanded_url: original});
	});
}

function _callback(err, result){
	if(result){
		this.done ++;
		this.results.push(result);
	}
	if(this.amount === this.done){
		this.cb(null, this.id, this.results);
	}
}

TwitterExpandURL.prototype.expand = function(id, obj, params, cb){

	this.cb = cb;
	this.id = id;
	this.results = [];
	params = params || {};
	this.force = params.force || false;

	var regex = /(\b(https?):\/\/[-A-Z0-9+&amp;@#\/%?=~_|!:,.;]*[-A-Z0-9+&amp;@#\/%=~_|])/ig;
	var match = obj.text.match(regex);

	if(match){

		var arr = _.merge(obj.entities.urls, obj.entities.media);

		this.amount = match.length;

		for(var i = 0;i < match.length;i++){

			var shortURL = match[i];

			if(_isValid(shortURL)){

				var found = _.find(arr, {"url": shortURL});

				if(found){

					if(_isShortened(found.expanded_url) && this.force){
						_expand.call(this, {url: found.expanded_url}, _callback.bind(this));
					}else{
						_callback.call(this, null, {url: shortURL, expanded_url: found.expanded_url});
					}

				}else if(obj.retweeted_status){

					var arr_rt = _.merge(obj.retweeted_status.entities.urls, obj.retweeted_status.entities.media);
					var found_rt = _.find(arr, {url: shortURL});

					if(found_rt){

						if(_isShortened(found.expanded_url) && this.force){
							_expand.call(this, {url: shortURL}, _callback.bind(this));
						}else{
							_callback.call(this, null, {url: shortURL, expanded_url: found_rt.expanded_url});
						}

					}else{
						if(this.force){
							_expand.call(this, {url: shortURL}, _callback.bind(this));
						}else{
							_callback.call(this, null, {url: shortURL, expanded_url: shortURL});
						}
					}

				}else{
					if(this.force){
						_expand.call(this, {url: match[i]}, _callback.bind(this));
					}else{
						_callback.call(this, null, {url: match[i], expanded_url: match[i]});
					}
				}

			}else{
				_callback.call(this, null, {url: shortURL, expanded_url: ""});
			}

		}

	}else{
		cb(null, this.results);
	}

};

module.exports = TwitterExpandURL;