Make JSONP requests to the Wikipedia API

wikipedia-jsonp.js

/*jslint browser: true*/
/*global define, exports, require, module, jsonp*/

/**
    A module for Jsonp requests to the Wikipedia API.
    @module wikipedia-jsonp
    @author Matt Barker
    @requires jsonp
*/
(function (factory) {
    'use strict';

    if (typeof define === 'function' && define.amd) {
        // AMD
        define(['jsonp'], factory);
    } else if (typeof exports === 'object') {
        // CommonJS
        module.exports = factory(require('jsonp'));
    } else {
        // Browser global
        window.WikipediaJsonp = factory(jsonp);
    }
}(function (jsonp) {
    'use strict';
    /**
        This callback type is used to handle JSONP responses.
        @callback requestCallback
        @param {Object} data - JSON response
    */

    /**
        Initialises a new instance of the WikipediaJsonp class.
        See the Query section of the API documentation for usage:
        {@link http://www.mediawiki.org/wiki/API:Query }
        @class WikipediaJsonp
        @param {string} url - The Wikipedia site
        @param {Object} [parameters] - Query parameters
        @param {requestCallback} [callback] - Function to pass the returned JSON data to
        @param {Object} [context] - Context for the callback function
        @example
        var url = 'http://en.wikipedia.org',
            parameters = {
            action: 'query',
            list: 'geosearch',
            gslimit: 100,
            gsradius: 1000,
            gscoord: '52.42350|-1.71347'
        };
    
        function callback(data) {
            console.log(data);
        }
    
        WikipediaJsonp(url, parameters, callback);
    
        // Alternative
        var wiki = new WikipediaJsonp(url);
    
        wiki.send(parameters, callback);
    */
    function WikipediaJsonp(url, parameters, callback, context) {
        if (!(this instanceof WikipediaJsonp)) {
            return new WikipediaJsonp(url, parameters, callback, context);
        }

        this.url = url;

        if (parameters) {
            this.send(parameters, callback, context);
        }
    }

    /**
        Send the request to the jsonp module.
        @param {Object} parameters - Query parameters
        @param {requestCallback} callback - Function to pass the returned JSON data to
        @param {Object} [context] - Context for the callback function
    */
    WikipediaJsonp.prototype.send = function (parameters, callback, context) {
        var query = '',
            key,
            url;

        for (key in parameters) {
            if (parameters.hasOwnProperty(key)) {
                query += '&' + key + '=' + encodeURIComponent(parameters[key]);
            }
        }

        url = this.url +  '/w/api.php?format=json' + query + '&callback=';
        jsonp(url, callback, context || this);
    };

    return WikipediaJsonp;
}));