A package that provides some helper functions for implementing leaf value changes and change tracking functionality to javascript objects, including arrays and classes.
- ☘️ Accessors for leaf values, including iteration
- 🌿 IntelliSense for leaf paths
- 🌳 Conversion of tree to/from leaves
- 🍂 Proposing, saving and reverting changes
- 🍁 Listing the changes, both as a list or as an object fragment
npm install leavify
import changes from 'leavify/changes';
interface Book {
title: string;
author: string;
year: number;
chapters: Chapter[];
}
interface Chapter {
title: string;
number: number;
}
const book: Book = {
title: 'The Golden Compass',
author: 'Philip Pullman',
year: 1995,
chapters: [{ title: 'The Decanter of Tokay', number: 1 }],
};
changes.propose(book, [
['author', 'Pullman'],
['chapters[0].number', 0],
]);
changes.save(book);
changes.getOriginal(book).chapters?.[0].number; // 1import changes from 'leavify/changes';
class Book {
title = 'default title';
get original() {
return changes.getOriginal(this, 'original', 'proposed');
}
get proposed() {
return changes.getProposed(this, 'original', 'proposed');
}
}
const book = new Book();
changes.propose(book, [['title', 'new title']]);
changes.save(book);
book.title; // 'new title'
book.original.title; // 'default title'import { walkLeaves, toTree } from 'leavify';
for (const [path, value] of walkLeaves(book)) {
console.log(path, value); // ['title', 'new title']
}
// Leaves to/from tree
const tree = toTree([...walkLeaves(book)]);Here's a brief description of each function defined:
get: get the leaf value of a given path
set: set the leaf value of a given path
has: truthy for a path that refers to a leaf value that exists
toTree: create a new object from a list of path-value entries
walkLeaves: iterate the path-value entries inside an object
findDifference: compare two objects and return the entries by which they differ
changes:
propose: push a list of entries to change
discard: delete the list of proposed entries
save: apply the proposed entries in-place
undo: propose a list of paths back to the original values, without applying
isSaved: truthy when there are no proposed (unsaved) changes
getOriginal: make an object from the original entries
getProposed: make an object from the proposed entries
getSavedEntries: list the applied entries - proposed and saved
cloneDeepAsOriginal: clone deep and undo changes