I'm relatively new to WCF services, so I apologize in advance if I'm missing the obvious. My business uses EasyPost as our shipping solution, and I've written a WCF service to handle the shipping status webhook calls from EasyPost, described here: https://www.easypost.com/docs/webhooks
Briefly, EasyPost sends an update object as JSON via POST. The problem is that it sends several different types of (non-configurable) updates to the same service method, and I'm finding it difficult to write a DataContract that encompasses all the possibilities. For example, if the argument it sends is a tracking number update, update.result.status will be a string value; if it's a batch status update, update.result.status will be an object. It's a bit of a mess.
I tried handling just the update type that I care about and returning a 400 status code on the others, but EasyPost interprets that as an outage and drops my service as a webhook endpoint.
From what I've read, it looks like I could abandon the comforts of a Data Contract in favor of using a System.ServiceModel.Channels.Message parameter as a catch-all, then parse the message manually. That doesn't strike me as a wise/clean solution, though.
I'd be grateful for any alternatives.
This is probably not the best way I could have handled this, but it works.
I have an HTTP Module that identifies whether the incoming request is for the proper service method, and if so, converts the ContentType header from "application/json" to "text/plain".
My service method accepts the content body as a System.IO.Stream parameter. By converting the stream to a byte[] and then to a string, I end up with the raw JSON string sent by EasyPost.
After that, it's just a matter of using Newtonsoft.Json to attempt to deserialize the JSON string into the expected Type.
Even if the deserialization fails, I can still log the data and send a success response to the caller. That's good enough for my purposes.