CODEWITHSUNDEEP
c#azureazureservicebusazure-webjobssdkazure-servicebus-topics
jimmy
jimmy

Reputation: 2031

Binding a type to Webjob SDK trigger

I am using Webjob SDK for serving an azure service bus.

It works fine and now I would like to start to parameterize the inputs to it.

I have been doing:

public static void ProcessTopicStatusMessage([ServiceBusTrigger("%topic%", "%subname%")] BrokeredMessage message,
    TextWriter logger)

Now i would also like to add an additional parameter: endpoint. Something like this:

public static void ProcessTopicStatusMessage([ServiceBusTrigger("%topic%", "%sub%")] BrokeredMessage message, Uri endPoint,
    TextWriter logger)

I figured that it would be possible by binding the URI type to the config like this:

config.BindingFactory.BindToInput<ServiceBusAttribute,Uri>(typeof(Uri), new Uri(myURI));

But it doesn't seem to work. Is this even possible or do I have to make my own custom trigger?

Upvotes: 1

Views: 195

Answers (1)

Thomas
Thomas

Reputation: 29746

As you mention, you can declare a static field to store you uri or you can inject it using a DI container. The JobHostConfiguration has a JobActivator that allows you to use DI.

Here I am using SimpleInjector(nuget) to create a custom job activator.

public class SimpleInjectorJobActivator : IJobActivator
{
    private readonly Container _container;

    public SimpleInjectorJobActivator(Container container)
    {
        _container = container;
    }

    public T CreateInstance<T>()
    {
        return (T)_container.GetInstance(typeof(T));
    }
}

Now you need to create a class that will encapsulate your function trigger:

public class TopicMessageProcessor
{
    private readonly Uri _myUry;

    public TopicMessageProcessor(Uri myUry)
    {
        _myUry = myUry;
    }

    public void ProcessTopicStatusMessage([ServiceBusTrigger("%topic%", "%sub%")] BrokeredMessage message,
        TextWriter logger)
    {
        // _myUry is accessible here
    }
}

In you main function, you need to configure the DI container:

static void Main()
{
    ...
    // get the uri from the config database
    Uri myUry = ...
    var container = new Container();
    container.Register(() => new TopicMessageProcessor(myUry));
    container.Verify();

    var config = new JobHostConfiguration
    {
        JobActivator = new SimpleInjectorJobActivator(container)
    };

    ...    
}

Just notice that this is a very simple example. Let me know if it helps.

Upvotes: 1

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