chickendinosaur-http/src/Http.js

Front-end, super slim, ajax, xhr, http library with promises.

/**
 * @author John Pittman <johnrichardpittman@gmail.com>
 */

(function(root, factory) {
    if (typeof define === 'function' && define.amd) {
        // AMD
        define(['./../../es6-promise/promise.min.js'], factory);
    } else if (typeof exports === 'object') {
        // Node, CommonJS-like
        module.exports = factory(require('es6-promise'));
    } else {
        // Browser globals (root is window)
        root.ChickenDinosaur = root.ChickenDinosaur || {};
        root.ChickenDinosaur.Http = factory(root.ES6Promise);
    }
}(this, function(ES6Promise) {
    'use strict'

    var Promise = ES6Promise.Promise;

    var parseResponseText = function(text) {
        var result;

        try {
            result = JSON.parse(text);
        } catch (e) {
            result = text;
        }

        return result;
    };

    var createXHR = function(method, url, data) {
        var promise = new Promise(function(resolve, reject) {
            var xhr = XMLHttpRequest !== 'undefined' ? new XMLHttpRequest() : new ActiveXObject('Microsoft.XMLHTTP');

            xhr.open(method, url, true);
            xhr.setRequestHeader('Content-type', 'application/json');
            xhr.onreadystatechange = function() {
                if (this.readyState === this.DONE) {
                    if (this.status === 200) {
                        // Success
                        resolve(parseResponseText(this.responseText));
                    } else {
                        // Error
                        reject(this);
                    }
                }
            };

            if (method === 'POST' ||
                method === 'PUT')
                xhr.send(JSON.stringify(data));
            else
                xhr.send();
        });

        return promise;
    };

    var createURL = function(url, params) {
        var queryURL = url.toString();
        for (var key in params) {
            queryURL += url.indexOf('?') !== -1 ? '&' : '?' + key + '=' + params[key];
        }

        return queryURL;
    };

    /**
     * Creates http requests.
     * @constructor
     */
    function Http() {
        /**
         * @param  {string} url
         * @param  {object} params - Query parameters.
         * @return {Promise}
         */
        this.get = function(url, params) {
            return createXHR('GET', (params === undefined) ? url : createURL(url, params));
        };

        /**
         * @param  {string} url
         * @param  {object} params - Request parameters.
         * @param  {object} data - Request body data to insert.
         * @return {Promise}
         */
        this.post = function(url, data, params) {
            return createXHR('POST', params === undefined ? url : createURL(url, params), data);
        };

        /**
         * @param  {string} url
         * @param  {object} params - Request parameters.
         * @param  {object} data - Request body data to update.
         * @return {Promise}
         */
        this.put = function(url, data, params) {
            return createXHR('PUT', params === undefined ? url : createURL(url, params), data);
        };

        /**
         * @param  {string} url
         * @param  {object} params - Query parameters.
         * @return {Promise}
         */
        this.delete = function(url, params) {
            return createXHR('DELETE', (params === undefined) ? url : createURL(url, params));
        };
    }

    return new Http();
}));