The function that is always triggered when a component is displayed in an Ionic2 application

Question

The function that is always triggered when a component is displayed in an Ionic2 application

Could there be a function that always triggers when a component is displayed in an ionic2 app?

For example, I've noticed that the constructor function in a component only triggers when the component is initialized for the first time or when you navigate to it from a different page using push.

However, the constructor will not trigger when the user clicks the back button or switches between tabs.

Is there a method that will be called every time the component is shown on the screen?

Update

After some research (which basically means googling ;)), I discovered that each tab maintains its own history stack. For instance, if I have tabs for home and search, any navigation actions in the search tab are isolated from the home tab.

So, here's what I want to achieve:

Perform a search in the search tab
Click on the search button in the search tab
Redirect to the home tab without displaying the search results again in the search tab itself

I hope this clarifies my requirement a bit more

angular typescript ionic2

Answer 1

Answer №1

One way to handle retrieving previous query results is by utilizing the ionViewDidEnter event on the result tab page. This event will trigger every time the page is entered, allowing you to fetch the result from a prior query stored in the service.

To see an example of this implementation, check out this plunker

In the page2.html file (the home tab), I've included the following code snippet:

  ionViewDidEnter(){
    this.result = this.tabService.result;
  }

This code ensures that each time a user navigates to this page, the result from the service will be retrieved again. This means that if the user didn't input any new query parameters on the previous tab, the previous query result will be utilized instead.

Answer 2

One way to handle retrieving previous query results is by utilizing the ionViewDidEnter event on the result tab page. This event will trigger every time the page is entered, allowing you to fetch the result from a prior query stored in the service.

To see an example of this implementation, check out this plunker

In the page2.html file (the home tab), I've included the following code snippet:

  ionViewDidEnter(){
    this.result = this.tabService.result;
  }

This code ensures that each time a user navigates to this page, the result from the service will be retrieved again. This means that if the user didn't input any new query parameters on the previous tab, the previous query result will be utilized instead.

Answer 3

Answer №2

In my opinion, the function ngOnInit() is exactly what you need. Any code inserted into this function will execute each time the page is initialized, but only after its data-bound properties have been received.

If you want to learn more about it, check out: https://angular.io/docs/ts/latest/api/core/index/OnInit-class.html

I hope this information meets your needs!

Answer 4

In my opinion, the function ngOnInit() is exactly what you need. Any code inserted into this function will execute each time the page is initialized, but only after its data-bound properties have been received.

If you want to learn more about it, check out: https://angular.io/docs/ts/latest/api/core/index/OnInit-class.html

I hope this information meets your needs!

The function that is always triggered when a component is displayed in an Ionic2 application

Update

Answer №1

Answer №2

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