RESTier提交逻辑，将错误消息推送到顶层

Question

I am using RESTier 0.6.0 library and would like to perform some checks on a resource before deleting it. In the event that the checks fail, I am throwing an Exception to stop the delete operation. However, the error message that I am using to instantiate the Exception is not getting pushed out at the highest level. I can only view the message as an inner exception when serving my Web API from Visual Studio. Is there a way to get this error message to push out at the highest level?

protected void OnDeletingGw_Pack(Gw_Pack pack)
{
    var trades = ModelContext.Gw_PackJunction.Where(e => e.PackID == pack.PackID).ToList();

    if (pack.Groupage == true || trades.Count > 1)
    {
            // Don't delete a pack if it is a groupage container or if it's associated with more than one Trade.
            throw new Exception("The container you are trying to delete is either marked as groupage or is functioning as a groupage container in another file.");
    }
}

Currently any Exception thrown within the OnDelete submit logic methods in the EntityFrameworkApi results in an error which looks like this:

{ "error":{ "code":"","message":"An error has occurred." } }

... which is not particularly useful to the client.

UPDATE: I noted in the RESTier documentation MkDocs version that an example was given where an ODataException (rather than Exception) was thrown. I changed this in my code, but the error object returned by the published Restier service still only has the basic "An error has occurred" information.

Assistance is greatly appreciated!

Answer 1

When throwing an Exception within the RESTier EntityFrameworkApi (inside and OnUpdate<EntitySet> method for example), the exception is deserialized as part of the inner exception (internalexception). So in order to view any exceptions thrown within the RESTier API, one needs to...

set the IncludeErrorDetailPolicy property on the HttpConfiguration class like this:

config.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always

Structure of error received by client

See this post: OData controller returns different error for local and different for remote machine