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Learn how to effectively send data between components in Angular using Observables with our step-by-step guide.
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How to Send Data Between Components in Angular Using Observables

In Angular development, it's common to need to share data between components. This can often lead to a struggle for developers, especially when dealing with events triggered by user actions. One of the most efficient ways to handle this is by using Observables. In this post, we will explore how to send data from one component to another using an Observable, focusing on a simple Angular example to illustrate the process.

Understanding the Problem

You have two components: a parent component and a child component. You want to transmit an object from the parent component to the child component whenever a user selects something from a list. This is typically done through an event — in our case, a click event. The challenge lies in efficiently managing this data transfer without multiple data subscriptions.

Setting Up the Service

To facilitate communication between the components, we will use a service. This service will have both get and set methods for our data:

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Explanation

Subject: A Subject is a type of Observable that allows values to be multicasted to many Observers.

setDataObject() Method: When called, it will emit a new value to all subscribers.

getDataObject() Method: This provides an observable version of the subject for the consumer components.

Implementing the Parent Component

In your parent component, you'll set up a method that triggers on a click event, sending data to the service:

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

Parent Component HTML

You can have a simple list where clicking on an item invokes the onSelect method:

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

Setting Up the Child Component

For the child component, you'll subscribe to the Observable provided by the service:

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

Child Component HTML

You'll then display the received data in the HTML template using the async pipe:

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

Explanation

Async Pipe: This pipe subscribes to the Observable and returns the latest value it has emitted. When the component is destroyed, the subscription is automatically canceled.

Conclusion

By following this approach, you can effectively share data between components in an Angular application using Observables. The structure allows you to maintain a clean component design, minimizing the need for deep prop drilling or bus implementations.

This method not only facilitates data transfer but also keeps your application responsive and efficient by leveraging the power of Observables.

Feel free to explore this method in your projects, adapting as necessary to fit your specific data structures and needs!