How to Get Type from a createAction Function in NGRX

Learn how to extract action payload typings in NGRX using the `ReturnType` utility without resorting to class-based actions.
---
This video is based on the question https://stackoverflow.com/q/64941048/ asked by the user 'Udi Mazor' ( https://stackoverflow.com/u/1931948/ ) and on the answer https://stackoverflow.com/a/75303135/ provided by the user 'Yas Ikeda' ( https://stackoverflow.com/u/9195902/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Get the type from a - "createAction" function

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/licensing
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding NGRX Actions: The Challenge

In Angular applications that use NGRX for state management, you often define actions using either class-based definitions or utility functions like createAction. While class-based methods provide typed payloads for actions, many developers prefer the cleaner syntax of createAction. However, a common challenge arises: How do you get the payload typings from an action created using createAction?

For example, when you create an action like this:

[[See Video to Reveal this Text or Code Snippet]]

And later, you want to utilize this in an effect that listens to that action, you may find yourself needing to define the action's type manually.

This can lead to tightly coupled code, making it hard to maintain. Let's explore how to simplify this process using a powerful TypeScript utility.

Simplifying Action Typings with ReturnType

The good news is: you don’t have to stick to creating class-based actions just to enjoy the benefits of typed payloads. You can still achieve this with actions defined using createAction by utilizing TypeScript's built-in ReturnType utility type.

Here’s how:

Step 1: Define Your Action

First, you define the action as shown below:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Extract the Action Type

To get the type of the action's payload, simply use the ReturnType utility like this:

[[See Video to Reveal this Text or Code Snippet]]

This will result in a type that looks like:

[[See Video to Reveal this Text or Code Snippet]]

This essentially gives you a well-typed action type that includes both the payload and the action type, making your effect clean and safe from type errors.

Implementing in Effects

Now that you have a type definition for the action, you can use it in your effects. For example:

[[See Video to Reveal this Text or Code Snippet]]

Advantages of Using ReturnType

Strong Typing: It allows for clear specifications of your action's payload without manual definitions, promoting better maintainability.

Decoupling: This approach reduces tight coupling between actions and effects, making it easier to manage changes in one without significantly impacting the other.

Readability: Code becomes more concise and easier to understand at a glance, as the types are inferred automatically.

Conclusion

Using the ReturnType utility provided by TypeScript alleviates the need for manual type definitions when working with actions defined through createAction. This method not only enhances the maintainability of your code but also boosts your productivity as a developer, allowing you to focus more on building great features rather than juggling typing issues.

By adopting this approach in your NGRX application, you'll find that defining and using typed actions becomes a hassle-free experience!

Видео How to Get Type from a createAction Function in NGRX канала vlogize