ServiceBusTrigger POCO Deserialization - azure

Question

I would like to see if/how it would be possible to plug into the deserialization process for a parameter that's decorated with the ServiceBusTrigger?
Say I have a function that looks like:
public static void HandleMessage([ServiceBusTrigger("myqueue")] MyCustomType myCustomType) { }
How would I go about taking over the deserialization? I know that there is a notion of an IArgumentBindingProvider and IArgumentBinding but it does not look like ServiceBusTrigger supports these concepts.
I know I can use GetBody<Stream>() and deserialize that way but I'd like to know if I can plug into the ServiceBusTrigger's pipeline. By the looks at the SDK, the ServiceBusTrigger has a hard coded list of IQueueArgumentBindingProviders and so I can't add my own.

Answer 1

If you have a look at the Azure WebJobs SDK Extensions, there is an overview on how to create your own bindings :
Binding Extensions Overview
Otherwise the ServiceBusConfiguration exposes a MessagingProvider property that allows you to intercept the ServiceBusTrigger pipeline:
private static void Main()
{
var sbConfig = new ServiceBusConfiguration()
{
MessagingProvider = // you implemetation of the MessagingProvider class goes here !!!
};
var config = new JobHostConfiguration();
config.UseServiceBus(sbConfig);
new JobHost(config).RunAndBlock();
}
Here is a simple skeleton of a MessagingProvider implementation:
public sealed class MyMessagingProvider : MessagingProvider
{
private readonly ServiceBusConfiguration _config;
public MyMessagingProvider(ServiceBusConfiguration config)
: base(config)
{
_config = config;
}
public override MessageProcessor CreateMessageProcessor(string entityPath)
{
return new MyMessageProcessor(_config.MessageOptions);
}
private class MyMessageProcessor : MessageProcessor
{
public MyMessageProcessor(OnMessageOptions messageOptions)
: base(messageOptions)
{
}
public override Task<bool> BeginProcessingMessageAsync(BrokeredMessage message, CancellationToken cancellationToken)
{
// Intercept the message before the execution of the triggerred function
return base.BeginProcessingMessageAsync(message, cancellationToken);
}
public override Task CompleteProcessingMessageAsync(BrokeredMessage message, FunctionResult result, CancellationToken cancellationToken)
{
// Intercept the message after the execution of the triggerred function and before being completed
return base.CompleteProcessingMessageAsync(message, result, cancellationToken);
}
}
}
So you're main function now looks like that:
private static void Main()
{
var sbConfig = new ServiceBusConfiguration();
sbConfig.MessagingProvider = new MyMessagingProvider(sbConfig);
var config = new JobHostConfiguration();
config.UseServiceBus(sbConfig);
new JobHost(config).RunAndBlock();
}