ballerinax/azure_functions Ballerina library

Overview

This module provides an annotation-based Azure Functions extension implementation for Ballerina.

Supported Triggers and bindings:

An Azure Function consists of a trigger and optional bindings. A trigger defines how a function is invoked. A binding is an approach in which you can declaratively connect other resources to the function. There are input and output bindings. An input binding is a source of data into the function. An output binding allows outputting data from the function to an external resource. For more information, go to Azure Functions triggers and bindings concepts.

• Http - Trigger and Output Binding
• Queue - Trigger and Output Binding
• Blob - Trigger, Input and Output Binding
• Twilio - Output Binding
• CosmosDB - Trigger, Input and Output Binding
• Timer - Trigger

Sample Code:

In ballerina, Triggers are represented with listeners. When the af:HttpListener gets attached to the service, it implies that the function is a HTTP Trigger. The resource function behaves exactly the same as a service written from ballerina/http. It supports http:Payload, http:Header annotations for parameters. Input binding annotations can be used to annotate parameters to make use of external services in azure. if no annotations are specified for a parameter, it's identified as a query parameter.

Output bindings are defined in the return type definition. For services with the HttpListener attachment, HttpOutput is the default Output binding. Of course, you can override the default behavior by specifying them explicitly in the return type.

import ballerinax/azure_functions as af;

service / on new af:HttpListener() {
    resource function get hello(string name) returns string {
        return "Hello, " + name + "!";
    }
}

In the code sample shown above, it has an empty service path and resource path named hello. The accessor is get. It expects a request with a query parameter for the field name. The required artifact generation and data binding will be handled by ballerinax/azure_functions package automatically.