export shop detail on dianping.com info to csv

dianping.js

(function(){
    function $$get_prop(obj, path) {
	return path.split('.').reduce(function(prev, curr) {
            return prev ? prev[curr] : ''
	}, obj || self)
    }

    function $$parse_page(doc){

	return {
	    name : $$get_prop(doc.querySelector('#basic-info .shop-name'), 'firstChild.nodeValue'),
	    category : $$get_prop(doc.querySelector('.breadcrumb'), 'innerText'),
	    rank : $$get_prop(doc.querySelector('#basic-info .brief-info .mid-rank-stars'), 'title'),
	    brief : $$get_prop(doc.querySelector('#basic-info .brief-info'), 'innerText'),
	    address : $$get_prop(doc.querySelector('#basic-info .expand-info.address'), 'innerText'),
	    phone : $$get_prop(doc.querySelector('#basic-info .expand-info.tel'), 'innerText')
	};   
    }

    function $$request_content(url, callback)
    {
	var xhr = new XMLHttpRequest();
	xhr.open('GET', url, true);
	xhr.responseType = 'document';
	//    xhr.overrideMimeType('text/xml');
	xhr.onload = function () {
	    if (xhr.readyState === xhr.DONE) {
		if (xhr.status === 200) {
		    callback(xhr.responseXML);
		}
	    }
	};
	xhr.send(null);
    }

    function $$request_page(url, callback)
    {
	$$request_content(url, function(obj){callback($$parse_page(obj));});
    }

    function $$to_csv(arr)
    {
	var json = arr;
	var fields = Object.keys(json[0]);
	var csv = json.map(function(row){
	    return fields.map(function(fieldName){
		return JSON.stringify(row[fieldName], function(key, value) { return value === null ? '' : value })
	    }).join(',')
	});
	csv.unshift(fields.join(','));

	return csv.join('\r\n');
    }

    function $$send_csv(arr)
    {
	var str = $$to_csv(arr);
	var data = new Blob([str], {type: 'text/plain'});
	var url = window.URL.createObjectURL(data);

	var a = document.createElement("a");
	document.body.appendChild(a);
	a.style = "display: none";
	a.href = url;
	a.download = "data.csv";
	a.click();
	
	window.URL.revokeObjectURL(url);
	a.parentNode.removeChild(a);
    }

    function $$parse_page_shops(doc, done_callback)
    {
	var _shop_count = 0;
	var _ready_count = 0;
	var _shop_ojbs = [];
	function _req_done_callback(obj){
	    _shop_ojbs.push(obj);
	    _ready_count++;
	    if(_shop_count == _ready_count)
	    {
		console.log("current page done");
		done_callback(doc, _shop_ojbs);
	    }else{
		console.log('shop parse done', obj);		
	    }
	};
	
	doc.querySelectorAll('.shop-all-list div.tit').forEach(
	    function(node){
		_shop_count++;
		(function(href){
		    setTimeout(function(){$$request_page(href, _req_done_callback);}, Math.floor(Math.random() * 30000));
		})(node.querySelector("a").href);
	    }
	)
    }
    
    function $$fetch_next_page(doc, callback)
    {
	$$request_content(doc.querySelector('.page > .next').href, callback);
    }
    
    function $$start(){
	var max_page = 0;
	var cur_page = 0;

	var shop_objs = [];
	
	
	var on_shop_list_done = function(doc, arr){
	    var start_parse = function(doc){
		$$parse_page_shops(doc, on_shop_list_done);
	    }
	    cur_page ++;
	    
	    shop_objs = shop_objs.concat(arr);
	    if(max_page == cur_page)
	    {
		$$send_csv(shop_objs);
	    }else{
		$$fetch_next_page(doc, start_parse);
	    }
	}
	if(max_page == 0)
	{
	    max_page = parseInt(prompt('how many pages do u want to get?'));
	}
	
	$$parse_page_shops(document, on_shop_list_done);
    }

    $$start();
})();