onchange equivalent in angular2

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i'm using onchange to save the value of my input range into firebase , but i have an error who say that my function is not defined.

this is my function

saverange(){
  this.Platform.ready().then(() => {
    this.rootRef.child("users").child(this.UserID).child('range').set(this.range)
  })
} 

this is my html

<ion-item>
  <ion-row>
    <ion-col>Rayon <span favorite><strong> {{range}} km</strong></span></ion-col>
    <ion-col><input type="range" name="points" min="0" max="40" [(ngModel)]="range" onchange="saverange()"></ion-col>
  </ion-row>
</ion-item>

what is the equivalent of onchange in angular , if one exist. thank you


We can use Angular event bindings to respond to any DOM event. The syntax is simple. We surround the DOM event name in parentheses and assign a quoted template statement to it. -- reference

Since change is on the list of standard DOM events, we can use it:

(change)="saverange()"

In your particular case, since you're using NgModel, you could break up the two-way binding like this instead:

[ngModel]="range" (ngModelChange)="saverange($event)"

Then

saverange(newValue) {
  this.range = newValue;
  this.Platform.ready().then(() => {
     this.rootRef.child("users").child(this.UserID).child('range').set(this.range)
  })
} 

However, with this approach saverange() is called with every keystroke, so you're probably better off using (change).

onchange equivalent in angular2, We can use Angular event bindings to respond to any DOM event. The syntax is simple. We surround the DOM event name in parentheses and On this page we will provide Angular OnChanges and SimpleChanges example. Angular provides lifecycle hooks for change detection. OnChanges is an interface and has a method declaration i.e ngOnChanges() . In parent-child component, the child component declares @Input() property to get values from parent component.


In Angular you can define event listeners like in the example below:

<!-- Here you can call public methods from parental component -->
<input (change)="method_name()"> 

Angular ng-change Directive, what to do when the value of an HTML element changes. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Learn more using the ng change in angular 2 using ng model variable


@Mark Rajcok gave a great solution for ion projects that include a range type input.

In any other case of non ion projects I will suggest this:

HTML:

<input type="text" name="points" #points maxlength="8" [(ngModel)]="range" (ngModelChange)="range=saverange($event, points)">

Component:

    onChangeAchievement(eventStr: string, eRef): string {

      //Do something (some manipulations) on input and than return it to be saved:

       //In case you need to force of modifing the Element-Reference value on-focus of input:
       var eventStrToReplace = eventStr.replace(/[^0-9,eE\.\+]+/g, "");
       if (eventStr != eventStrToReplace) {
           eRef.value = eventStrToReplace;
       }

      return this.getNumberOnChange(eventStr);

    }

The idea here:

  1. Letting the (ngModelChange) method to do the Setter job:

    (ngModelChange)="range=saverange($event, points)

  2. Enabling direct access to the native Dom element using this call:

    eRef.value = eventStrToReplace;

ngOnChanges only runs when the Input change comes from a , only runs when the Input change comes from a template binding like <component [someInput]="aValue"> . If you set it manually like this component. someInput = aValue , that happens outside the change detection cycle and you need to let Angular know somehow that you've changed something. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Learn more Get current value when change select option - Angular2


Angular ngOnChanges life Cycle Hook, when it detects changes to data bound input property. This method receives a SimpeChanges object, which contains the current and previous property values. The child Component decorates the property as a @Input annotation. I am using Angular 2 (TypeScript). I want to do something with the new selection, but what I get in onChange() is always the last selection. How can I get the new selection? &lt;select [(ngModel)]="


OnChanges, A lifecycle hook that is called when any data-bound property of a directive changes. Define an ngOnChanges() method to handle the changes. Angular is a platform for building mobile and desktop web applications. Join the community of millions of developers who build compelling user interfaces with Angular.


ngChange, It will not wait until all changes are made, or when the input field loses focus. The ng-change event is only triggered if there is a actual change in the input value, Angular 1 does not accept onchange() event, it's only accepts ng-change() event.. Angular 2, on the other hand, accepts both (change) and (ngModelChange) events, which both seems to be doing the same thing.