diff2 v0.1.7

diff2

Calculate the difference between two JavaScript objects and apply them to other JavaScript objects.

API

diff.calculateDifferences(oldObject, newObject)

Calculate the differences between the old object and the new object. The differences will be output as a series of actions.

diff.applyDifferences(targetObject, differences)

Apply calculated differences to an object. This can also be an empty object to get a tree like representation of the differences.

Example

Given:

oldObject = {
  property: 'value',
  nestedObject: {
    foo: 'bar',
    number: 1
  },
  array: [1, 2, 3, 4, 5]
};

newObject = {
  property: 'new value',
  nestedObject: {
    foo: 'baz'
  },
  newNestedObject: {
    bar: 'foo'
  },
  array: [3, 2, 1, 4]
};

Executing diff.calculateDifferences(oldObject, newObject); will output:

[ { type: 'changed',
    path: [ { key: 'property', valueType: 'string' } ],
    value: 'new value' },
  { type: 'changed',
    path:
     [ { key: 'nestedObject', valueType: 'object' },
       { key: 'foo', valueType: 'string' } ],
    value: 'baz' },
  { type: 'deleted',
    path:
     [ { key: 'nestedObject', valueType: 'object' },
       { key: 'number', valueType: 'undefined' } ],
    value: undefined },
  { type: 'changed',
    path:
     [ { key: 'array', valueType: 'array' },
       { key: '0', valueType: 'number' } ],
    value: 3 },
  { type: 'changed',
    path:
     [ { key: 'array', valueType: 'array' },
       { key: '2', valueType: 'number' } ],
    value: 1 },
  { type: 'deleted',
    path:
     [ { key: 'array', valueType: 'array' },
       { key: '4', valueType: 'undefined' } ],
    value: undefined },
  { type: 'added',
    path: [ { key: 'newNestedObject', valueType: 'object' } ],
    value: { bar: 'foo' } } ]

Executing diff.applyDifferences(oldObject, differences); will cause oldObject to deep equal newObject.

Executing diff.applyDifferences(emptyObject, differences); will result in a tree like representation:

{ property: 'new value',
  nestedObject: { foo: 'baz' },
  array: [ 3, , 1 ],
  newNestedObject: { bar: 'foo' } }