Real-time extraction from web pages of HTML gadgets and associated properties using node-dom based on given criterias


Node.js implementation of Extract Widget using

Real-time extraction of HTML gadgets and associated properties from web pages based on given criterias.

It can be used as a server or an API, then parameters are passed in the URL, or directly as an independant node.js module.

npm install node-gadgets


git clone
cd node-gadgets
npm link .

Complementary modules : node-ewa

 Note : node-ewa is not a public module for now, so you can only use node-gadgets's server/API mode. 
gengadgets.js :
    var genGadgets = require('node-gadgets').genGadgets;
    var $E=encodeURIComponent;
    var response={
        end:function(gadgets) {
            //output format, see below
    var params='url='+'&name=test';
    params +='&fetch='+$E('{"img":"", "input":""}')+'&proc='+$E('{"img":"","input":""}')+'&gadget=true&price=true&regexp='+$E(\\$|€')&search='+$E('Koncept californie')&nbmax=20;
    //possible params (see below) : url-fetch-proc-gadget-price-search-regexp-nbmax
    var http = require('http'),  
    URL = require('url'),
    genGadgets = require('node-gadgets').genGadgets;
    var handleRequest = function (request, response) {
        var qs = URL.parse(request.url);
        if (qs.pathname == '/gengadgets'){

To call it directly :

http://myserver:myport/gengadgets?url={"img":"", "input":""}&proc={"img":"","input":""}&gadget=true&price=true&regexp=$|€&nbmax=20

Example with encoded parameters :

To call it from a script :

    var xscript=document.createElement('SCRIPT');
    var params='url='+'&name=test';
    params +='&fetch='+$E('{"img":"", "input":""}')+'&proc='+$E('{"img":"","input":""}')+'&gadget=true&price=true&regexp='+$E('\\$|€')+'&nbmax=20';
    xscript.onload or onreadystatechange --> do what you have to do with the output

Output format (see more details below) : test.gadgets=(Array containing the gadgets) (where 'test' does correspond to the parameter 'name')

Example : xscript.onload=function() {alert(test.gadgets)};

Note : if your regexp does contain "\" and if you pass it through a js var (Example above : $E('\\$|€')) make sure to double it.

Note2 : make sure the encoding of your files/browsers is utf-8

url : the url of the site where you want to extract gadgets from.

name : the name that will become the name of the global var containing the output in its 'gadgets' property (example : test.gadgets).

fetch : node-dom FetchExternalResources parameter, recommended value : {"img":"", "input":""}

proc : node-dom ProcessExternalResources parameter, recommended value : {"img":"", "input":""}

regexp : while building the DOM, node-dom will use that regular expression to detect the objects that you are looking for (example : regexp=$|€ --> you are looking for gadgets in the page that are related to a price in $ or €)

gadget : if present, indicates that you want the HTML of the gadget to be in the output

price : if present, indicates that you want the price (if any) associated to the gadget to be present in the output

search : if present, indicates that once the gadgets have been selected with the regexp, you can filter these gadgets based on the value of search (example : you have selected on a sport web sites gadgets related to a price, you want in the output only gadgets related to shoes, then you might use search=shoe)

nbmax : important parameter for performances, the value does specify a limit for the weight of searched gadgets so node-gadgets does not spend a lot of time processing gadgets that are not relevant. The default value is 100, recommended value is 20.

The output is an Array of :

[gadget html,width,height,gadget name,reserved,base,price,html of regexp object]

No json format here for now for historical reasons and backward compatibility with existing projects (TODO later).

gadget html : the html of the gadget.

width and height : width/height of the gadget

gadget name : the name that node-gadgets has processed for the gadget (example : Nike Sportswear Shox Rivalry Baskets Basses 115$)

base : the baseURI of the target web site (must be added as a BASE tag when using gadget's html to reconstruct it)

price : the price associated to the gadget if it exists (example : 115$ for our example above)

html of regexp object : html of the initial object detected with the regexp from which the gadget has been constructed (example : a price, then node gadget will see if a gadget can be constructed from this price looking at his parents and checking if the result can be considered as a product)


Webble project : (quick test : click on OK, then on first link that appears)

jCore server ( :

Example :

You can use the API on jCore server : (if by any unforeseen reasons the server is down, please advise).

See tests.txt in ./test