Tips for refreshing the current Angular 2 Component

Question

Tips for refreshing the current Angular 2 Component

I'm looking for a way to refresh the same component in Angular 2. Can anyone provide guidance?

Below is the code snippet I have:

import { Component, OnInit, ElementRef, Renderer } from '@angular/core';
import { Router, ActivatedRoute, Params } from '@angular/router';
import { productModel } from '../_models/index';
import { categoryListService } from '../_services/index';

@Component({
  selector: 'app-product',
  templateUrl: 'product.component.html',
  styleUrls: ['product.component.css']
})
export class productComponent implements OnInit {
  uidproduct: productModel;
  param: number;
  constructor(
    private elementRef: ElementRef,
    private route: ActivatedRoute,
    private router: Router,
    private categoryListService: categoryListService) { }

  ngOnInit() {
    this.route.params.subscribe(product => {
      console.log('logging sub product obj', product);
    });
    this.uidproduct = JSON.parse(sessionStorage.getItem('product'));
    var s = document.createElement("script");
    s.type = "text/javascript";
    s.src = "http://this/external/script/needs/to/be/loaded/each/time.js";
    this.elementRef.nativeElement.appendChild(s);
  }
  nextproduct(){ 
    let i = this.uidproduct.order;
    this.categoryListService.findNextproduct(this.uidproduct);
    this.param = ++i;
    this.router.navigate([`/product/${this.param}`]);
  }
}

nextproduct() method is triggered by a click event in the template.

The uidproduct represents a JSON object with various properties and I'm updating the DOM using {{uidproduct.classname}}

In the HTML template, it's used like this:

<div id="selected-product" class="{{uidproduct.classname}}">

Whenever I click the

<button (click)="nextproduct()">

, the class property in the DOM changes but I need to reload the component for the external script to take effect.

javascript angular typescript angular-components

Answer 1

Answer №1

If you want to update the content of a template, you can utilize the *ngIf directive:

@Component({
  selector: '...',
  template: `
<ng-container *ngIf="!updateContent">
 template content goes here
</ng-container>`
})
export class MyComponent {
  updateContent = false;
  constructor(private cdRef:ChangeDetectorRef){}
  doUpdate() {
    this.updateContent = true;
    this.cdRef.detectChanges();
    this.updateContent = false;
  }
}

Answer 2

If you want to update the content of a template, you can utilize the *ngIf directive:

@Component({
  selector: '...',
  template: `
<ng-container *ngIf="!updateContent">
 template content goes here
</ng-container>`
})
export class MyComponent {
  updateContent = false;
  constructor(private cdRef:ChangeDetectorRef){}
  doUpdate() {
    this.updateContent = true;
    this.cdRef.detectChanges();
    this.updateContent = false;
  }
}

Answer 3

Answer №2

Why is there a need to constantly reload the component? If you have bound the fields of uidproduct, then simply refreshing that should update the values displayed in the component. Reloading the component only adds unnecessary overhead.

If you still feel there is a valid reason for reloading, follow these steps:

Go to another component, even a blank one.
Immediately navigate back to the original component.

The key is to ensure that the first navigation is completed before proceeding with the second.

In your component, include NavigationEnd:

import { Router, NavigationEnd } from '@angular/router';

Then subscribe to it inside the constructor:

constructor(private thingService: ThisThingService, private router: Router) { 
   router.events.subscribe(event => {
    if (event instanceof NavigationEnd) {
      if (event.url === '/blank') {
        this.router.navigate(['product']); 
      }
    }
  });

Note that I wait for NavigationEnd event and check if I am navigating to the blank component's path. If so, I redirect back to the product component. If passing an ID is necessary, store it on the object and include it here.

Instead of directing to the product page in nextproduct(), redirect to blank.

this.router.navigate(['blank']);

This method should effectively reload your component. An issue to consider is that the subscribe call in the constructor will run every time the component is reloaded. As a challenge, try removing it from the constructor and creating a dedicated service for it, or incorporating it into the app component's constructor, routing module, or any other appropriate location.

Answer 4

Why is there a need to constantly reload the component? If you have bound the fields of uidproduct, then simply refreshing that should update the values displayed in the component. Reloading the component only adds unnecessary overhead.

If you still feel there is a valid reason for reloading, follow these steps:

Go to another component, even a blank one.
Immediately navigate back to the original component.

The key is to ensure that the first navigation is completed before proceeding with the second.

In your component, include NavigationEnd:

import { Router, NavigationEnd } from '@angular/router';

Then subscribe to it inside the constructor:

constructor(private thingService: ThisThingService, private router: Router) { 
   router.events.subscribe(event => {
    if (event instanceof NavigationEnd) {
      if (event.url === '/blank') {
        this.router.navigate(['product']); 
      }
    }
  });

Note that I wait for NavigationEnd event and check if I am navigating to the blank component's path. If so, I redirect back to the product component. If passing an ID is necessary, store it on the object and include it here.

Instead of directing to the product page in nextproduct(), redirect to blank.

this.router.navigate(['blank']);

This method should effectively reload your component. An issue to consider is that the subscribe call in the constructor will run every time the component is reloaded. As a challenge, try removing it from the constructor and creating a dedicated service for it, or incorporating it into the app component's constructor, routing module, or any other appropriate location.

Tips for refreshing the current Angular 2 Component

Answer №1

Answer №2

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