https://github.com/Rich-Harris/object-cull

Create a copy of an object with just the bits you actually need
https://github.com/Rich-Harris/object-cull

Last synced: 16 days ago
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Create a copy of an object with just the bits you actually need

• Host: GitHub
• URL: https://github.com/Rich-Harris/object-cull
• Owner: Rich-Harris
• License: mit
• Created: 2019-05-10T17:26:16.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2023-05-01T02:28:57.000Z (over 1 year ago)
• Last Synced: 2024-10-02T13:34:50.917Z (about 1 month ago)
• Language: TypeScript
• Size: 122 KB
• Stars: 144
• Watchers: 4
• Forks: 2
• Open Issues: 5
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

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README

        
# object-cull

Create a copy of an object, based on which properties were accessed.

```js

import { prepare, apply } from 'object-cull';

const proxy = prepare({

	firstname: 'Terrell',

	lastname: 'Snider',

	friends: [

		{ firstname: 'Rachelle', lastname: 'Knight' },

		{ firstname: 'Ila', lastname: 'Farrell' },

		{ firstname: 'Vasquez', lastname: 'Flynn' }

	],

	pets: [

		{ name: 'Bobo', species: 'Great Dane' }

	]

});

console.log(proxy.firstname); // Terrell

console.log(proxy.friends[0].firstname); // Rachelle

const { kept, culled } = apply(proxy);

console.log(kept);

/*

{ firstname: 'Terrell', friends: [ { firstname: 'Rachelle' } ] }

*/

console.log(culled);

/*

[

	{ path: 'lastname', value: 'Snider' },

	{ path: 'friends.0.lastname', value: 'Knight' },

	{ path: 'friends.1', value: { firstname: 'Ila', lastname: 'Farrell' } },

	{ path: 'friends.2', value: { firstname: 'Vasquez', lastname: 'Flynn' } },

	{ path: 'pets', value: [ { name: 'Bobo', species: 'Great Dane' } ] }

]

*/

const unused_bytes = culled.reduce((total, item) => {

	return total + JSON.stringify(item.value).length;

}, 0);

const percent_unused = 100 * unused_bytes / JSON.stringify(proxy).length;

console.log(`${percent_unused}% of the data was unused`);

```

## Why?

Mostly for server-side rendering. You might not need to serialize *all* your data to send it to the client.

## Prior art

* [js-off](https://github.com/reconbot/js-off)

## License

MIT