Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'https://localhost:xxxxx' is therefore not allowed access

While developing an adal.js app with OData in IISExpress, I'm getting the following error:

Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'https://localhost:44315' is therefore not allowed access

Turns out the problem is that I needed to include the CORS package from Microsoft:

Install-Package Microsoft.AspNet.WebApi.Cors

Once that's in there, I also need to enable CORS using the 'EnableCors' extension method on my HttpConfiguration.

Using ADAL.js correctly with AngularJS when setting up your endpoints

When searching around and using the tutorials on how to correctly use adal.js to authenticate your calls to Web API (or anything else) in Azure, you'll often see a block similar to this that you have to put in your App.js to configure your main module:

adalAuthenticationServiceProvider.init(
{
tenant: 'mytenant.onmicrosoft.com',
clientId: 'abc4db9b-9c54-4fdf-abcd-1234ec148319',
endpoints: {
'https://localhost:44301/api': 'https://some-app-id-uri/'
}
},
$httpProvider
);

You'll notice that this appears to be pointing to the Web API root of a service running on localhost, and you'd be right. For this to work correctly, you'll need to enable OAUTH 2 path matching in the application manifest of the **client** that's connecting to the service!

Using adal.js and getting error AADSTS65001: The user or administrator has not consented to use the application with ID '....'

It turns out that you have to actually go in and give your javascript web client permissions to access the web api application in the Azure Active Directory management portal. Go figure.

Using adal.js and getting error AADSTS70005: response_type="token" not supported

I've recently started using adal.js with OData in an AngularJS 1.5 application and been getting this error with attempting to connect my client-side XHR requests to my Web API application.

Following the advice here, changing the AAD manifest of the AngularJS web client from this:

"oauth2AllowImplicitFlow": false

... to this:

"oauth2AllowImplicitFlow": true

... seems to have solved the problem.

Using ADAL in Javascript to enable use of Azure Active Directory from an AngularJS SPA

Check this out, apparently it came out last fall in Azure:

http://www.cloudidentity.com/blog/2014/10/28/adal-javascript-and-angularjs-deep-dive/