Passing variables from a template to TypeScript using ngFor

Question

Passing variables from a template to TypeScript using ngFor

Need help passing a variable from a template to typescript using *ngFor loop.

Currently, my code looks like this:

 <select (change)="onregionchange()" data-placeholder="Regions" class="form-control regions-select" id="regions" multiple>
    <option *ngFor="let region of all_regions" [value]="region.id">{{region.name}}</option>
</select>

I want to send countries for the selected region to the ts file and store them in region.countries within the onregionchange() function.

Any suggestions on how to achieve this in angular2?

angular typescript angular2-template

Answer 1

Answer №1

Ensure that when you call the onregionchange() function, all the options are passed in like this: change($event.target.options).

In your TypeScript file, make sure to extract only the selected options as you are receiving all variables. Here is an example:

onregionchange(countries) {
    this.selectedregions = Array.apply(null,countries)
      .filter(country => country.selected)
      .map(country=> country.value)
  }

You can also refer to this example for more information.

Answer 2

Ensure that when you call the onregionchange() function, all the options are passed in like this: change($event.target.options).

In your TypeScript file, make sure to extract only the selected options as you are receiving all variables. Here is an example:

onregionchange(countries) {
    this.selectedregions = Array.apply(null,countries)
      .filter(country => country.selected)
      .map(country=> country.value)
  }

You can also refer to this example for more information.

Answer 3

Answer №2

If you have an onchange handler on your select element, you can utilize it like this:

<select (change)="onregionchange()" data-placeholder="Regions" class="form-control regions-select" id="regions" multiple>
    <option *ngFor="let region of all_regions" [value]="region.id">{{region.name}}</option>
</select>

function onregionchange(e){
    console.log(e.target.value)
}

By setting the value of each option to region.id, you will be able to retrieve the selected region's ID in the event listener function. From there, you should be able to access other properties such as region.country.

Answer 4

If you have an onchange handler on your select element, you can utilize it like this:

<select (change)="onregionchange()" data-placeholder="Regions" class="form-control regions-select" id="regions" multiple>
    <option *ngFor="let region of all_regions" [value]="region.id">{{region.name}}</option>
</select>

function onregionchange(e){
    console.log(e.target.value)
}

By setting the value of each option to region.id, you will be able to retrieve the selected region's ID in the event listener function. From there, you should be able to access other properties such as region.country.

Passing variables from a template to TypeScript using ngFor

Answer №1

Answer №2

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