Docs - describe customization in message pump (#83)

* Docs - describe customization in message pump

* pr-sug: update index page

* pr-sug: update index page

* pr-sug: add back arrows to doc pages

docs/features/message-pumps/customization.md

@@ -0,0 +1,43 @@
+---
+title: "Message Pump Customization"
+layout: default
+---
+
+# Customize Message Pumps
+
+While the message processing is handled by the `IMessageHandler<>` implementations, the message pump controls in what format the message is received.
+We allow several customizations while implementing your own message pump.
+
+## Control Custom Deserialization
+
+When inheriting from an `...MessagePump` type, there's a way to control how the incoming raw message is being deserialized.
+Based on the message type of the registered message handlers, the pump determines if the incoming message can be deserialized to that type.
+
+```csharp
+public class OrderMessagePump : MessagePump
+{
+    public OrderMessagePump(
+        IConfiguration configuration, 
+        IServiceProvider serviceProvider, 
+        ILogger<OrderMessagePump> logger)
+        : base(configuration, serviceProvider, logger)
+    {
+    }
+
+    public override bool TryDeserializeToMessageFormat(string message, Type messageType, out object? result)
+    {
+        if (messageType == typeof(Order))
+        {
+            result = JsonConvert.DeserializeObject<Order>(message);
+            return true;
+        }
+        else
+        {
+            result = null;
+            return false;
+        }
+    }
+}
+```
+
+[&larr; back](/)

docs/features/message-pumps/service-bus.md

@@ -181,3 +181,5 @@ We provide templates to get started easily:
 
 - Azure Service Bus Queue Worker Template ([docs](https://templates.arcus-azure.net/features/servicebus-queue-worker-template))
 - Azure Service Bus Topic Worker Template ([docs](https://templates.arcus-azure.net/features/servicebus-topic-worker-template))
+
+[← back](/)

docs/features/service-bus.md

@@ -65,3 +65,5 @@ This information can be acces in a more simplified way:
 MessageContext messageContext = ...
 Encoding encoding = messageContext.GetMessageEncodingProperty();
 ```
+
+[← back](/)

docs/index.md

@@ -14,7 +14,9 @@ Coming soon!
 
 - Support for using message pumps for the following brokers:
     - Azure Service Bus ([docs](features/message-pumps/service-bus))
+    - Azure Service Bus Extensions ([docs](features/service-bus))
 - Support for exposing TCP health probes to periodically check liveness/readiness of the host ([docs](features/tcp-health-probe))
+- Customize message pumps ([docs](features/message-pumps/customization))
 
 # License
 This is licensed under The MIT License (MIT). Which means that you can use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the web application. But you always need to state that Codit is the original author of this web application.