midasplatform/Midas

// Midas Server. Copyright Kitware SAS. Licensed under the Apache License 2.0.

/* global json */

var ajaxWebApi = {};

/**
 * Wraps the jQuery ajax function with mechanisms to handle
 * authentication to the web API and parsing and logging of the
 * response object, including error handling
 * Parameters:
 *   method: Web API method to call (such as midas.bitstream.list)
 *   [args]: Key=value arguments to the web API method, delimited with &
 *   [success]: Function to be called when this function is finished (one
 *              arg, the response json object)
 *   [error]: Function to be called if the request fails (one arg, the
 *            response json object)
 *   [complete]: Function to be called when done with the request, whether or
 *               not it was successful
 *   [log]: jQuerified DOM object representing the log area where output will
 *          be written. Default behavior is alert() in error conditions.
 */
ajaxWebApi.ajax = function (params) {
    'use strict';
    if (!params.method) {
        alert('ajaxWebApi.ajax: method parameter not set');
        return;
    }

    this._webApiCall(params);
};

/** Internal function.  Do not call directly. */
ajaxWebApi._webApiCall = function (params) {
    'use strict';
    if (!params.args) {
        params.args = 'useSession=true';
    }
    else {
        params.args += '&useSession=true';
    }

    $.ajax({
        type: 'POST',
        url: json.global.webroot + '/api/json?method=' + encodeURIComponent(params.method),
        data: params.args,
        dataType: 'json',
        success: function (retVal) {
            if (params.complete) {
                params.complete();
            }
            if (retVal.stat == 'fail') {
                ajaxWebApi.logError(params.method + '?' + params.args + ' failed: ' + retVal.message, params.log);
                if (params.error) {
                    params.error(retVal);
                }
                return;
            }
            if (params.success) {
                params.success(retVal);
            }
        },
        error: function () {
            ajaxWebApi.logError('Ajax call to web API returned an error (' +
                json.global.webroot + '/api/json' + '?' + encodeURIComponent(params.method) + '&' + encodeURIComponent(params.args) + ')', params.log);
            if (params.complete) {
                params.complete();
            }
        }
    });
};

ajaxWebApi.logMessage = function (text, log) {
    'use strict';
    if (log) {
        log.append('<span style="color:black;">' + text + '</span><br>');
    }
    else {
        alert(text);
    }
};

ajaxWebApi.logError = function (text, log) {
    'use strict';
    if (log) {
        log.append('<span style="color:red;">Error: ' + text + '</span><br>');
    }
    else {
        alert('Error: ' + text);
    }
};