No 'Access-Control-Allow-Origin' header is

Question

XMLHttpRequest cannot load http://mywebservice. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:9000' is therefore not allowed access.

I get this error when I try to run my web-service from inside my code. I tried finding about it and tried many solutions which were suggested which I found on net. Pasting the code below.

<form name="LoginForm" ng-controller="LoginCtrl" ng-submit="init(username,password,country)">
    <label>Country</label><input type="text" ng-model="country"/><br/><br/>
    <label>UserName</label><input type="text" ng-model="username" /></br></br>
    <label>Password</label><input type="password" ng-model="password">
    </br>
    <button type="submit" >Login</button>
</form>

And controller form the corresponding js is:

app.controller('LoginController', ['$http', '$scope', function ($scope, $http) {
    $scope.login = function (credentials) {
    $http.get('http://mywebservice').success(function ( data ) {
        alert(data);
        });
    }
}]);

The web-service works fine when I hit it from URL bar. How to resolve the problem? Kindly help!

Answer 1

The Chrome Webstore has an extension that adds the 'Access-Control-Allow-Origin' header for you when there is an asynchronous call in the page that tries to access a different host than yours.

The name of the extension is: "Allow-Control-Allow-Origin: *" and this is the link: https://chrome.google.com/webstore/detail/allow-control-allow-origi/nlfbmbojpeacfghkpbjhddihlkkiljbi

Answer 2

Use this extension for chrome. Allows to you request any site with ajax from any source. Adds to response 'Allow-Control-Allow-Origin: *' header

https://chrome.google.com/webstore/detail/allow-control-allow-origi/nlfbmbojpeacfghkpbjhddihlkkiljbi/related

Answer 3

On the client side you can enable cors requests in AngularJS via

app.config(['$httpProvider', function($httpProvider) {
        $httpProvider.defaults.useXDomain = true;
        delete $httpProvider.defaults.headers.common['X-Requested-With'];
    }
]);

However if this still returns an error, this would imply that the server that you are making the request has to allow CORS request and has to be configured for that.

Answer 4

I added this and it worked fine for me.

web.api

config.EnableCors();

Then you will call the model using cors:

In a controller you will add at the top for global scope or on each class. It's up to you.

 [EnableCorsAttribute("http://localhost:51003/", "*", "*")]

Also, when your pushing this data to Angular it wants to see the .cshtml file being called as well, or it will push the data but not populate your view.

(function () {
    "use strict";
    angular.module('common.services',
        ['ngResource'])
    .constant('appSettings',
    {
        serverPath: "http://localhost:51003/About"
    });
}());

//Replace URL with the appropriate path from production server.

I hope this helps anyone out, it took me a while to understand Entity Framework, and why CORS is so useful.

Answer 5

Replace get with jsonp:

 $http.jsonp('http://mywebservice').success(function ( data ) {
    alert(data);
    });
}

Answer 6

If you are using chrome: try open chrome with the args to disable web security like you see here:

Disable same origin policy in Chrome