Your output binding's goal is to send items to your connector or service.
In the previous step, you defined the Factory that will create instances of your connector or service.
In this step, we will define the IAsyncCollector<T> implementation that will receive these items and process them through an instance of your connector or service.
IAsyncCollector<T> defines two methods:
- Task AddAsync(T item, CancellationToken cancellationToken = default(CancellationToken))
- Task FlushAsync(CancellationToken cancellationToken = default(CancellationToken))
You can implement them in your own custom way, depending on how your connector or service can process items and what kind of experience you want the consumer to have.
AddAsync will be called each time the consumer wants to pass down an item into your binding, you could choose to process it at this time (like in the example), or add it to a batch.
FlushAsync will be called at the end of the Function execution, if you opted for adding items to a batch, this is the right time to process them all.
- Define a Context, it should contain both a reference to your Attribute and a reference to an instance of your connector or service. We will see how this Context is created in the next step.
- Define your own implementation of
AsyncCollector<T>, like CosmosDBBindingAsyncCollector. Your Collector will be receiving a Context on the constructor that can be used inAddAsyncand/orFlushAsync.