ajax.js

var methods          =   {
        get      : 'GET',
        post     : 'POST',
        put      : 'PUT',
        'delete' : 'DELETE',
        patch    : 'PATCH'
    },
    defaultHeaders = {
         
    };

var doRequest = function(cfg, originalCfg) {
    // API: https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest
    var request = new XMLHttpRequest(),
        url;

    if (cfg.url) {
        url = cfg.url
    }
    else if (cfg.endpoint) {
        url = urlRoot + cfg.endpoint
    }
    else {
        throw("Ajax: No url or endpoint defined");
    }


    request.open(cfg.method, url);


    // Set request headers
    for (var headerName in defaultHeaders) {
        request.setRequestHeader(headerName, defaultHeaders[headerName]);
    }

    /*
        0   UNSENT  open() has not been called yet.
        1   OPENED  send() has been called.
        2   HEADERS_RECEIVED    send() has been called, and headers and status are available.
        3   LOADING Downloading; responseText holds partial data.
        4   DONE    The operation is complete.
    */
    request.onreadystatechange = function(event) {
        // Skip if we're not done
        if (request.readyState !== 4) {
            return;
        }

        var responseData;
        // console.log('request');
        // console.log(request);
        // debugger;
        if (request.responseType == 'json') {
            responseData = requeset.response;
        }
        else if (request.responseText) {
            try {
                responseData = JSON.parse(request.responseText);
            }
            catch(e) {
                
            }
            
        }

        if (request.status === 200) {
            // console.log('success', request.resonseText);

            if (cfg.success) {
                cfg.success.call(cfg.success || {}, responseData, originalCfg, request);
            }
        }
        else {
            console.log('failure');
            console.log(request);
            console.log(event);

            if (cfg.success) {
                cfg.success.call(cfg.success || {}, responseData, originalCfg, request);
            }

        }
    };

    request.send();
}


var Ajax = {
    get : function(cfg) {
        var requestCfg = Object.assign({}, cfg);
        requestCfg.method = methods.get;
        doRequest(requestCfg, cfg);

    },
    post : function(cfg) {

    },
    put : function(cfg) {

    },
    'delete' : function(cfg) {

    },
    patch : function(cfg) {

    }
};



module.exports = Ajax;