README

ember-set-helper

A better mut helper!

{{this.greeting}}

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

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

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).

Passing a dynamic path

You can pass a path dynamically using to the helper as well:

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

Picking values with `ember-composable-helpers`

With the {{action}} helper and modifier, you could specify a value path using the value named argument:

<input {{on "input" (action (mut this.value) value="target.value"))}}/>

You can accomplish the same thing with {{set}} by using the {{pick}} helper from ember-composable-helpers to first pick the value off of the event, and then pass it to {{set}}:

<input {{on "input" (pick "target.value" (set this "value"))}}>

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

Compatibility

Ember.js v3.4 or above
Ember CLI v2.13 or above
Node.js v8 or above

Installation

ember install ember-set-helper

Contributing

See the Contributing guide for details.

License

This project is licensed under the MIT License.

Usage no npm install needed!