Built-in Helpers

In the last section you learned how to write a helper. A helper is usually a simple function that can be used in any template. Ember comes with a few helpers that can make developing your templates a bit easier. These helpers can allow you to be more dynamic in passing data to another helper or component.

The {{get}} helper makes it easy to dynamically send the value of a variable to another helper or component. This can be useful if you want to output one of several values based on the result of a computed property.

{{get address part}}

if the part computed property returns "zip", this will display the result of this.get('address.zip'). If it returns "city", you get this.get('address.city').

In the last section it was discussed that helpers can be nested. This can be combined with these sorts of dynamic helpers. For example, the {{concat}} helper makes it easy to dynamically send a number of parameters to a component or helper as a single parameter in the format of a concatenated string.

{{get "foo" (concat "item" index)}}

This will display the result of this.get('foo.item1') when index is 1, and this.get('foo.item2') when index is 2, etc.