ember-cli-custom-properties

Adds support for CSS custom properties (variables) to your application

Installation

ember install ember-cli-custom-properties

Features

• Uses modifiers to apply custom properties
• Maps component attributes to CSS custom properties
• Fast, lightweight implementation
• Only updates CSS custom properties when its bound component value changes
• Zero configuration design
• Production ready

Usage: Ember 2.17 and above

Starting with Ember 2.17 or later, we switched to using modifiers to set custom properties on an element. This design decision makes it a lot easier to apply a custom property at any level of the application, including top-level templates.

Here is the new an improved way for setting a custom property. You just need to make sure the variables passed into the modifier is tracked.

<div {{custom-property "--background-image" backgroundImage}}></div>

The first parameter to the modifier is the custom property in from your CSS file. The second parameter is the value of the custom property.

Usage: Ember 2.16 or earlier

There is no extra installation steps need to use this add-on. It will automatically reopen the Component class an apply the CustomProperties mixin.

You just need to define the customProperties attribute on the target component to declare what properties on the component automatically map to CSS custom properties.

import Component from "@ember/component";

export default Component.extend ({
  customProperties: ['foo', 'fooBar']
});

In the example above, foo is mapped to --foo and fooBar is mapped to --foo-bar.

Custom property values are Promise aware. This is useful when the custom property's value must be computed in the background.

Custom Property Bindings

The custom properties defined in customProperties are automatically mapped to CSS custom properties. If you need to control what component property maps to a CSS custom property, define the property in customPropertyBindings.

import Component from "@ember/component";

// ...

export default Component.extend ({
  customPropertyBindings: ['height:--my-component-height']
});

Now, when you set the height property on this component, it will map to the --my-component-height CSS custom property.

Removing a Property

You remove a CSS custom property value by simply setting its bound component property to null or undefined.

Happy Coding!