Implementation of the missing "Ember.computed.dynamicAlias"

dynamic-alias.js

import Ember from 'ember';

// @see http://emberjs.jsbin.com/beboga/edit?js,output

export default function dynamicAlias(target, keyKey) {
  var prefix = target ? `${target}.` : '';
  var dynamicAliasKey = `${prefix}${keyKey}_alias`;
  return Ember.computed(function() {
    var key = `${prefix}${this.get(keyKey)}`;
    Ember.defineProperty(this, dynamicAliasKey, Ember.computed.alias(key));
    return this.get(key);
  }).property(keyKey, dynamicAliasKey);
}

Is this an alias or a oneWay?

  Ember.computed.dynamicAlias = function(target, keyKey) {
    const prefix = target ? `${target}.` : '';
    const dynamicAliasKey = `${prefix}${keyKey}_alias`;
    return Ember.computed(keyKey, dynamicAliasKey, function() {
      const key = `${prefix}${this.get(keyKey)}`;
      Ember.defineProperty(this, dynamicAliasKey, Ember.computed.alias(key));
      return this.get(key);
    });
  };

I have a dynamically generated form and the alias is used in this manner:
form-field.js

value: Ember.computed.dynamicAlias('model', 'field.value')

Where field.get('value') would be something like 'name', 'brand', 'productType' (attributes on the model).

And then
form-field.hbs

{{input value=value}}

But if the value on the model is updated, it doesn't trigger the value computed attribute to be updated.

@pwfisher any thoughts?

curious about this as well.

@lcpriest @pwfisher this is what I came up with

Ember.computed.dynamicAlias = function(target, aliasedKey) {
  return Ember.computed(aliasedKey, `${target}.${aliasedKey}_alias`, {
    get() {
      Ember.defineProperty(this, `${target}.${aliasedKey}_alias`, Ember.computed.alias(`${target}.${this.get(aliasedKey)}`));
      return this.get(`${target}.${this.get(aliasedKey)}`);
    },
    set(key, value) {
      return this.set(`${target}.${this.get(aliasedKey)}`, value);
    },
  });
};

any thoughts..?

one last refinement

Ember.computed.dynamicAlias = function(target, aliasedKey) {
  const aliasedProperty = `${target}.${aliasedKey}_alias`;
  return Ember.computed(aliasedKey, aliasedProperty, {
    get() {
      Ember.defineProperty(this, aliasedProperty, Ember.computed.alias(`${target}.${this.get(aliasedKey)}`));
      return this.get(aliasedProperty);
    },
    set(key, value) {
      return this.set(aliasedProperty, value);
    },
  });
};

weird.. was using this as

property: dynamicAlias('object', 'key'),

and was using an observer to check to make sure it was working, and once i removed the observer.. it broke..

  letsSee: Ember.observer('object.key_alias', function() {}),

not sure why I needed that..? maybe that alias need to be using somewhere..? not sure yet. will do more investigation.

import Ember from 'ember';

export function dynamicAlias(target, aliasedKey) {
  const aliasedProperty = `${aliasedKey}_unique_alias`;
  return Ember.computed(aliasedKey, aliasedProperty, {
    get() {
      Ember.defineProperty(this, aliasedProperty, Ember.computed.alias(`${target}.${this.get(aliasedKey)}`));
      return this.get(aliasedProperty);
    },
    set(key, value) {
      return this.set(aliasedProperty, value);
    },
  });
}

didn't need the target in the alias property