Ember-simple-set-helper NPM

ember-simple-set-helper

A(nother) better mut helper!

{{this.greeting}}

<button {{on "click" (set this.greeting "Hello!")}}>
  English
</button>

<button {{on "click" (fn (set this.greeting) "Hola!")}}>
  Español
</button>

This addon is a more direct replacement for Ember's mut helper than other alternatives (such as ember-set-helper).

Usage

The {{set}} helper returns a function that sets a value. This can be used in combination with Ember's {{on}} modifier or component actions to update state without having to write your own custom action. For simple cases, this is pretty handy:

<button {{on "click" (set this.greeting "Hello!")}}>
  English
</button>

Setting Passed Values

If you do not provide a value to the set helper, it will set the value that is provided to it when called. For example:

<!-- app/components/counter.hbs -->
{{this.count}}

<button {{on "click" this.updateCount}}>Add 1</button>

// app/components/counter.js
import Component from '@glimmer/component';
import { tracked } from '@glimmer/tracking';
import { action } from '@ember/object';

export default class Counter extends Component {
  @tracked count = 0;

  @action
  updateCount() {
    this.count++;

    if (this.args.onClick) {
      this.args.onClick(this.count);
    }
  }
}

<!-- usage -->
<Counter @onClick={{set this.currentCount}} />

This will set the value of this.currentCount to whatever value is passed to it when it is called (in this case the count of the counter component whenever a user clicks the button).

Differences from `mut`

No need to call wrap the helper (e.g. (set this.foo) === (fn (mut this.foo)))
Optional last parameter if setting a static value (e.g. (set this.foo "bar") === (fn (mut this.foo) "bar"))
Cannot be used as both a getter and setter for the value, only provides a setter