Breeze using angular $http interceptor

Question

I use a angular $http interceptor, to check if a ajax request returns 401 (not authenticated). If response is 401, the original request gets queued, a login form is shown and after login successfully, it retries the queued requests. This already works with $http, and the source for the angular interceptor is:

define('common.service.security.interceptor', ['angular'], function() {
'use strict';

angular.module('common.service.security.interceptor', ['common.service.security.retryQueue'])

.factory('securityInterceptor', [
    '$injector',
    '$location',
    'securityRetryQueue',
    function($injector, $location, securityRetryQueue) {

        return function(promise) {

            var $http = $injector.get('$http');


            // catch the erroneous requests
            return promise.then(null, function(originalResponse){
                if(originalResponse.status === 401){
                    promise = securityRetryQueue.pushRetryFn('Unauthorized', function retryRequest(){
                        return $injector.get('$http')(originalResponse.config);
                    });
                }

                 return promise;
            });
        };
    }
])

// register the interceptor to the angular http service. method)
.config(['$httpProvider', function($httpProvider) {
    $httpProvider.responseInterceptors.push('securityInterceptor');

}]);});

How can I make breeze request using this angular $http interceptor?

Breeze provides a wrapper for the angular $http service in the file "Breeze/Adapters/breeze.ajax.angular.js". So the first idea was to tell breeze to use it:

breeze.config.initializeAdapterInstance("ajax", "angular", true);

Debugging angular.js, it shows that breeze now in fact uses $http, but it does not execute the above registered interceptor. Inside $http, there is an array "reversedInterceptors", which holds the registered interceptors. I log this array to console. If i use $http, the length of this array is one (as expected), but when making request with breeze, this array is empty.

The question is, how can i use this $http interceptor with breeze requests?

Here is the code for breeze.ajax.angular.js, provided by breeze

define('breeze.ajax.angular.module', ['breeze', 'angular'], function (breeze) {
'use strict';
/* jshint ignore:start */
var core = breeze.core;

var httpService;
var rootScope;

var ctor = function () {
    this.name = "angular";
    this.defaultSettings = {};
};

ctor.prototype.initialize = function () {

    var ng = core.requireLib("angular");

    if (ng) {
        var $injector = ng.injector(['ng']);
        $injector.invoke(['$http', '$rootScope',
            function (xHttp, xRootScope) {
                httpService = xHttp;
                rootScope = xRootScope;
        }]);
    }

};

ctor.prototype.setHttp = function (http) {
    httpService = http;
    rootScope = null; // to suppress rootScope.digest
};

ctor.prototype.ajax = function (config) {
    if (!httpService) {
        throw new Error("Unable to locate angular for ajax adapter");
    }
    var ngConfig = {
        method: config.type,
        url: config.url,
        dataType: config.dataType,
        contentType: config.contentType,
        crossDomain: config.crossDomain
    }

    if (config.params) {
        // Hack: because of the way that Angular handles writing parameters out to the url.
        // so this approach takes over the url param writing completely.
        // See: http://victorblog.com/2012/12/20/make-angularjs-http-service-behave-like-jquery-ajax/
        var delim = (ngConfig.url.indexOf("?") >= 0) ? "&" : "?";
        ngConfig.url = ngConfig.url + delim + encodeParams(config.params);
    }

    if (config.data) {
        ngConfig.data = config.data;
    }

    if (!core.isEmpty(this.defaultSettings)) {
        var compositeConfig = core.extend({}, this.defaultSettings);
        ngConfig = core.extend(compositeConfig, ngConfig);
    }

    httpService(ngConfig).success(function (data, status, headers, xconfig) {
        // HACK: because $http returns a server side null as a string containing "null" - this is WRONG.
        if (data === "null") data = null;
        var httpResponse = {
            data: data,
            status: status,
            getHeaders: headers,
            config: config
        };
        config.success(httpResponse);
    }).error(function (data, status, headers, xconfig) {
        var httpResponse = {
            data: data,
            status: status,
            getHeaders: headers,
            config: config
        };
        config.error(httpResponse);
    });
    rootScope && rootScope.$digest();
};

function encodeParams(obj) {
    var query = '';
    var key, subValue, innerObj;

    for (var name in obj) {
        var value = obj[name];

        if (value instanceof Array) {
            for (var i = 0; i < value.length; ++i) {
                subValue = value[i];
                fullSubName = name + '[' + i + ']';
                innerObj = {};
                innerObj[fullSubName] = subValue;
                query += encodeParams(innerObj) + '&';
            }
        } else if (value instanceof Object) {
            for (var subName in value) {
                subValue = value[subName];
                fullSubName = name + '[' + subName + ']';
                innerObj = {};
                innerObj[fullSubName] = subValue;
                query += encodeParams(innerObj) + '&';
            }
        } else if (value !== undefined) {
            query += encodeURIComponent(name) + '=' + encodeURIComponent(value) + '&';
        }
    }

    return query.length ? query.substr(0, query.length - 1) : query;
}


breeze.config.registerAdapter("ajax", ctor);

breeze.config.initializeAdapterInstance("ajax", "angular", true);
/* jshint ignore:end */
});

Answer 1

using the setHttp method works for me to use http interceptors with the breeze angular ajax adapter. in my environment, it looks like this:

(function() {
    'use strict';

    var serviceId = 'entityManagerFactory';
    angular.module('app').factory(serviceId, ['$http', emFactory]);

    function emFactory($http) {

        var instance = breeze.config.initializeAdapterInstance("ajax", "angular");
        instance.setHttp($http);

        ...

    }
})();

the only place I've really found any information about this is in the release notes for 1.4.4 on the download page. I don't really understand what this does. i'm sure one of the breeze guys will have a better explanation.

Answer 2

You have to call setHttp($http) as explained by @almaplayera. Please mark his as the correct answer.

Here's why that is necessary.

By default, the breeze angular ajax adapter initializes itself with whatever instance of $http is available. Unfortunately, at the time that most scripts are loading, the $http instance for YOUR APP hasn't been created. That won't happen until your module loads ... which typically happens long after breeze loads.

So rather than create an adapter that won't work at all, breeze spins up its own instance of $http and wires the angular ajax adapter to that instance.

If your code doesn't do anything special, this works fine. It's not optimal; you'll get one extra $digest cycle than necessary. But it works for most people and let's admit that there is more than enough configuration noise to deal with as it is.

But you ARE doing something special. You're configuring a very specific instance of $http, not the one that breeze created for itself.

So you have to tell breeze to use YOUR instance of $http ... and that's what happens when you call setHttp($http);

Thanks to this feedback I have updated the breeze documentation on ajax adapters to describe how to configure for an Angular app.