Mobile Services: How to handle the case where your query string is too long?

Question

With Azure Mobile Services Offline Support I'm issuing a PullAsync query like so:

// This list contains 53 emails
var deviceContactEmails = new List<string> { "[email protected]", "[email protected]", ... };
var query = _userTable.Where(x => deviceContactEmails.Contains(x.Email));
await _userTable.PullAsync(query);

The Mobile Services SDK translates query into a URL encoded GET request with a filter like so (this was a list of 60 emails used for the Contains but I cut out a lot of the middle for brevity):

https://rememberwhen.azure-mobile.net/tables/User?$filter=((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((email%20eq%20'carlin_jmecwrv_stulberg%40tfbnw.net')%20or%20(email%20eq%20'carlin_jmecwrv_stulberg%40tfbnw.net'))%20or%20(email%20eq%20'carlin_jmecwrv_stulberg%40tfbnw.net'))%20eq%20'carlin_jmecwrv_stulberg%40tfbnw.net'))%20or%20(email%20eq%20'carlin_jmecwrv_stulberg%40tfbnw.net'))&$skip=0&$top=50&__includeDeleted=true&__systemproperties=__createdAt%2C__version

The problem is that if deviceContactEmails is too long, the service will complain about the query string length. Trying to filter on this many items in the URL is a problem, so I need to filter by passing the items in the body of the request with JSON or some other way.

So I guess the question is: How do I correctly set this up using the Mobile Service SDK with offline support so I can avoid exceeding the limit on the query string length in the URL encoded request?

Answer 1

It looks like I need to create a custom API to send the list of emails as the body of the request. I'll update this answer and accept if I solve it.