angular-jsend

An AngularJS module providing a wrapper around $http that handles JSend responses.

v0.1.5

Overview

Use this module in your AngularJS app if your API sends responses formatted in accordance with the JSend specification.

Installation

bower install angular-jsend --save

Usage

Add jsend as a dependency to your module:

var app = angular.module('app', ['jsend']);

Then call the jsend method and pass it the same config object that you would normally pass to the $http method. For example, assume you have an users service that makes calls to a /api/users endpoint and that this endpoint responds with JSend objects.

app.service('users', function(jsend, $q) {

    /**
     * Get all users.
     *
     * @returns {Promise} A promise resolved with an array of users.
     */
    this.getUsers = function() {
        return jsend({
            method: 'GET',
            url: '/api/users'
        }).then(
            function(response) {
                return response.data;
            },
            function(response) {
                return $q.reject(response);
            }
        );
    };

    /**
     * Get all users that are administrators.
     *
     * @returns {Promise} A promise resolved with an array of administrators.
     */
    this.getAdmins = function() {
        return jsend({
            method: 'GET',
            url: '/api/users',
            params: {
                admin: true
            }
        }).then(
            function(response) {
                return response.data;
            },
            function(response) {
                return $q.reject(response);
            }
        );
    }
});

Features

How is calling jsend(config) different that calling $http(config)?

The angular-jsend utility provides a few features that help you deal with JSend responses.

Calling jsend returns a promise that is resolved or rejected based on the JSend status and not the HTTP response status code. This is important. You may have an API where all responses are returned using a 200 (OK) response but the JSend status could be fail or error. The promise is rejected regardless of the 200 (OK) HTTP response status.
If your API returns a standard HTTP response such as 404 (Not Found) but does not return a JSend object, then a JSend object is created with the appropriate status, code, and message properties and the promise is rejected with this object.

API

jsend(config).then(successCallback, errorCallback);

The jsend module exports the jsend method. This method takes the same config parameter as the $http method. However, the response is always guaranteed to be a JSend object and the returned promise is resolved only if the JSend status is success. Otherwise, the promise is rejected with a JSend object having a status of fail or error.

Events

At the beginning of each request, a jsend:request event is broadcast on the $rootScope. The first and only argument is the config object passed to the jsend method.

$rootScope.on('jsend:start', function(config) {
    ...
});

When a JSend response is received, one of the following three events is broadcast on the $rootScope: jsend:success, jsend:fail, or jsend:error. The first argument is the config object passed to the jsend method and the second argument is the JSend response object.

$rootScope.on('jsend:success', function(ev, config, response) {
    console.log('Success');
});

$rootScope.on('jsend:fail', function(ev, config, response) {
    console.log('Fail');
});

$rootScope.on('jsend:error', function(ev, config, response) {
    console.log('Error');
});

Synthetic Error Responses

If the endpoint called by the jsend method returns a standard HTTP response with a body that is not formatted as a JSend object, then a synthetic JSend error response object is created from the HTTP status code and message. The status property of this response object will be set to "success" for HTTP status codes in the range 200 to 299 and "error" in all other cases. For an error response, the code property is set to the HTTP status code.

This is done so that your app only has to deal with JSend responses and need not have special handling for non-successful HTTP responses. Note that this only occurs if the API endpoint does not send back a JSend object. This allows you to send back JSend fail or error responses while also setting the HTTP status code to a meaningful value thereby complying with established REST principles.

For example, returning the following...

{
    "status": "fail",
    "data": {
        "title": "A title is required when creating a new post."
    }
}

...along with an HTTP status code of 400 (Bad Request), will not cause a synthetic error response to be created as the response already is a JSend object. As a matter of fact, if this fail response were returned with a 200 (OK) status code, the promise would still be rejected since the JSend status indicates that the request was not successful.

Logging

The jsend service logs all responses using the AngularJS $log facility.

A success status is logged using $log.debug.
A fail status is logged using $log.warn.
A error status is logged using $log.error.

Each log entry consists of three parts: the status (e.g., jsend:success), the config object that generated the request, and the response.

Response logging can be disabled by calling ev.preventDefault() in one of the event handlers. Example:

$rootScope.on('jsend:success', function(ev, config, response) {
    ev.preventDefault(); // the response is not logged
});

License

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

buchanan-edwards/angular-jsend