Developing Azure Functions

1. Developing Azure Functions

In this video, you'll learn how triggers and bindings extend Azure Functions.

2. What are triggers?

A trigger defines how a function is invoked. Functions can respond to many types of events - such as HTTP requests, new messages in a queue, or a file being uploaded. Each function must have exactly one trigger. For instance, a payment system might use a queue trigger to process transactions as soon as they're added to the queue, while an IoT solution could use an Event Hub trigger to process live sensor data streaming from connected devices.

3. Common trigger types

HTTP triggers are widely used for APIs and webhooks, allowing developers to expose serverless endpoints with minimal setup. Timer triggers are ideal for recurring jobs like cleaning up logs, generating daily reports, or sending reminders. Queue triggers enable asynchronous processing, perfect for background jobs that need reliability but not real-time execution. Blob triggers, on the other hand, respond automatically when files are uploaded, which makes them excellent for building pipelines that process images, videos, or large data files as soon as they appear in storage.

4. What are bindings?

Bindings simplify the way functions connect to external data and services by handling the integration behind the scenes, so you don't need to write repetitive connection code. Instead of writing connection logic for a database or storage account, you configure a binding in function settings. A function triggered by a queue message could instantly push results to a database through an output binding. This declarative approach keeps your code lean and focused on solving business problems rather than managing infrastructure details.

5. Input vs. output bindings

Input bindings provide data directly to your function as parameters. For example, you can automatically receive a blob file or a database record without manually opening a connection. Output bindings send results to services like Cosmos DB, Event Hubs, or email providers.

6. Input vs. output bindings

Imagine a function triggered by a new customer sign-up: the input binding retrieves the sign-up data, while output bindings simultaneously store it in a database and send a welcome email - without a single line of connection code.

7. Multiple bindings

Functions can use several bindings together to create streamlined workflows. Consider a blob-triggered function that receives an uploaded invoice. An input binding could provide the file contents, while output bindings could store processed results in Cosmos DB and notify a team via email. Combining bindings in this way reduces repetitive code, simplifies integration, and accelerates development of real-world workflows that would otherwise require multiple services stitched together manually.

8. Real-world example

Consider a photo-sharing application. When a user uploads an image, a blob trigger automatically starts the function. An input binding supplies the image directly to the function for processing. The function might resize the picture or add tags, and output bindings can then store the updated image, record metadata in Cosmos DB, and send a notification. This streamlined flow shows how triggers and bindings work together to build complete workflows with minimal code.

9. Let's practice!

Now it's your turn to apply triggers and bindings in some exercises!

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