Angular 2 signal sender

I have a specific class definition for my Project:

export class Project {
  $key: string;
  file: File;
  name: string;
  title: string;
  cat: string;
  url: string;
  progress: number;
  createdAt: Date = new Date();

  constructor(file: File) {
    this.file = file;
  }
}

Within my upload component, I successfully upload all the project information to my database/storage.

Next, I display all the Projects in the home.component as follows:

Upload.Service :

 getUploads() {
    this.uploads = this.db.list(`profile/${this.auth.userId}/project`).snapshotChanges().map((actions) => {
      return actions.map((a) => {
        const data = a.payload.val();
        this.showVisualContent(data.url, data.name);
        const $key = a.payload.key;
        const $ref = a.payload.ref;
        return { $key, ...data, $ref };
      });
    });
    return this.uploads;
  }

Home.Component :

 uploads: Observable<Project[]>;

ngOnInit() {
    this.uploads = this.navSrv.getUploads();
    }

Home.html :

 <div *ngFor="let project of uploads | async" class="responsive-width">
  <mat-card-title class="project-card-title">{{project.name}}</mat-card-title>
</div>

This approach allows me to showcase all projects in the home.component. What I aim to achieve is:

  • Click on one of the projects within the home.component.
  • Transition to a child component.
  • Display only the clicked project's information (not all projects).

While I have limited knowledge about event emitters (which I may need to utilize), I am unsure how to access the specific project that was clicked and display it in the child component. How can I accomplish this?

getOneProject() { //and pass it to another component

}

Answer №1

When dealing with this type of issue, there is no need for EventEmitters. EventEmitters are typically used for passing data from a Child Component to a Parent Component, not the other way around.

It seems like you want to be able to click on an element and be redirected to a component that displays only the specific project data associated with that element. In order to achieve this, you would need to set up a route (such as /projectComponent) and utilize routerLink to redirect to that route when the element is clicked, passing along the project data. Here's an example:

<div *ngFor="let project of uploads | async" class="responsive-width">
    <mat-card-title class="project-card-title" [routerLink]="['./projectComponent', project]"> {{project.name}}</mat-card-title>
</div>

I hope this explanation clarifies things for you!

Answer №2

In the scenario where the Project component serves as a subcomponent of the Home component, there is no need for an event emitter. Simply utilize the @Input() decorator within the parent's template to transmit all necessary data to the child component. For more detailed information on this process, reference the official Angular documentation focusing on how to pass data from parent to child using input binding.

Answer №3

Events cannot be inherited from a parent to a child component; it is recommended to utilize a service instead.

In essence, you should create a separate component for your project and loop through it. Then, set a click event in the HTML to trigger a function that will update some data in the service based on the selected project.

Subsequently, you just need to retrieve this information from the service in your child component.

The main solution is roughly outlined below:

export class ProjectHandlerService {
    public projectInfo: any;

    setProjectInfo(info: any) {
        this.projectInfo = info;
    }
}

@Component({//configuration parameters})
export class ProjectComponent {
    $key: string;
    file: File;
    name: string;
    title: string;
    category: string;
    url: string;
    progress: number;
    createdAt: Date = new Date();

    constructor(file: File, private projectHandler: ProjectHandlerService) {
      this.file = file;
    }

    onClick() {
        this.projectHandler.setProjectInfo(//data to pass)
    }
  }

Answer №4

Essentially, the Task (child) element should include an input attribute:

import {Component, Input, OnInit} from '@angular/core';

...

export class TaskComponent implements OnInit {

  @Input("task") task: Task;
  ...
}

Then, within the Home component template, your loop should bind to this input attribute:

<div *ngFor="let task of tasks | async" class="responsive-width">
  <mat-card-title class="task-card-title" [task]=task></mat-card-title>
</div>

This approach allows you to pass the task attribute and display it in the child component.

In this specific scenario, emitting an event with an event emitter is not necessary, as this is typically used when passing data from a child component to its parent.

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