https://github.com/eugeneware/changeset

Library to diff JSON objects into atomic put and delete operations, and apply change sets to objects. Useful with Levelup/LevelDB object synchronization.
https://github.com/eugeneware/changeset

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Library to diff JSON objects into atomic put and delete operations, and apply change sets to objects. Useful with Levelup/LevelDB object synchronization.

• Host: GitHub
• URL: https://github.com/eugeneware/changeset
• Owner: eugeneware
• License: other
• Created: 2013-06-10T06:48:37.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2021-06-12T17:38:20.000Z (over 3 years ago)
• Last Synced: 2024-10-30T20:50:27.993Z (9 days ago)
• Language: JavaScript
• Size: 67.4 KB
• Stars: 121
• Watchers: 2
• Forks: 9
• Open Issues: 9
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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• awesome-starred - eugeneware/changeset - Library to diff JSON objects into atomic put and delete operations, and apply change sets to objects. Useful with Levelup/LevelDB object synchronization. (others)

README

        
# changeset

Generate diff changesets for javascript objects, decomposing diffs into a series of puts and delete operations. The format is similar to the [levelup](https://github.com/rvagg/node-levelup) [batch](https://github.com/rvagg/node-levelup#batch) operation list for bulk operations.

Handles circular references of Objects and Arrays.

[![build status](https://secure.travis-ci.org/eugeneware/changeset.png)](http://travis-ci.org/eugeneware/changeset)

# Example

Take a diff of two objects and produce a list of transformation operations:

``` js

var diff = require('changeset');

var a = {

  name: 'Eugene',

  number: 42,

  tags: ['tag1', 'tag2', 'tag3'],

  scores: {

    tetris: 1000,

    carmageddon: 3

  }

};

var b = {

  name: 'Susan',

  number: 43,

  tags: ['tag1', 'tag4'],

  scores: {

    carmageddon: 3,

    zelda: 3000

  },

  age: 37

};

var changes = diff(a, b);

expect(changes).to.deep.equal([

  { type: 'put', key: ['name'], value: 'Susan' },

  { type: 'put', key: ['number'], value: 43 },

  { type: 'put', key: ['tags', '1'], value: 'tag4' },

  { type: 'del', key: ['tags', '2'] },

  { type: 'del', key: ['scores', 'tetris'] },

  { type: 'put', key: ['scores', 'zelda'], value: 3000 },

  { type: 'put', key: ['age'], value: 37 }

]);

```

Apply an operational changeset and apply it to an object to get a transformed object:

``` js

var diff = require('changeset');

var changes = [

  { type: 'put', key: ['name'], value: 'Susan' },

  { type: 'put', key: ['number'], value: 43 },

  { type: 'put', key: ['tags', '1'], value: 'tag4' },

  { type: 'del', key: ['tags', '2'] },

  { type: 'del', key: ['scores', 'tetris'] },

  { type: 'put', key: ['scores', 'zelda'], value: 3000 },

  { type: 'put', key: ['age'], value: 37 }

];

var a = {

  name: 'Eugene',

  number: 42,

  tags: ['tag1', 'tag2', 'tag3'],

  scores: {

    tetris: 1000,

    carmageddon: 3

  }

};

// apply the changes to a

var b_ = diff.apply(changes, a);

var b = {

  name: 'Susan',

  number: 43,

  tags: ['tag1', 'tag4'],

  scores: {

    carmageddon: 3,

    zelda: 3000

  },

  age: 37

};

// the transformed object should now equal b

expect(b_).to.deep.equals(b);

```

By default ```apply``` will return a new modified object after applying the

changeset. If you want to modify the destination, pass true as the third

parameter:

``` js

// apply the changes to a and modify a

var b_ = diff.apply(changes, a, true);

// a is now modified, and b_ is the same as a

expect(b_).to.equal(a);

```