ember-polyfillsember-cached-decorator-polyfill
Polyfill for RFC 566 "@cached decorator".
Installation
ember install ember-cached-decorator-polyfill
For addons, pass the -S flag.
If you're working in an environment with an explicit Babel config (like a V2
addon or an app with ember-cli-babel's { useBabelConfig: true }
mode), see "Explicit Babel Config" below.
Compatibility
- Ember.js v3.13 or above
- Ember CLI v2.13 or above
- Node.js v14 or above
Summary
Add a @cached decorator for memoizing the result of a getter based on
autotracking. In the following example, fullName would only recalculate if
firstName or lastName is updated.
import { tracked, cached } from '@glimmer/tracking';
class Person {
@tracked firstName = 'Jen';
@tracked lastName = 'Weber';
@cached
get fullName() {
return `${this.firstName} ${this.lastName}`;
}
}
For detailed usage instructions, refer to the RFC 566 "@cached decorator".
TypeScript Usage
TypeScript's normal type resolution for an import from @glimmer/tracking
will not find the types provided by this polyfill, since the actual
@glimmer/tracking package does not include an export for cache.
In order for TypeScript to recognize the extra cache export, add an import
like this somewhere in your codebase (like app.ts or test-helper.ts):
import 'ember-cached-decorator-polyfill';
Once the upstream types have been updated to reflect RFC 566, this will no longer be necessary.
Explicit Babel Config
In environments where you have an explicit Babel config (like authoring a V2
addon) you will need to configure this polyfill's babel plugin. Add it to your
babel.config.js like:
{
"plugins": [
"ember-cached-decorator-polyfill/babel-plugin"
]
}