jsonpatch-extended.js

Javascript library to apply JSON Patches with JSON Pointer syntax extensions.

Code adapted from jsonpatch-js by Byron Ruth.

References:

• JSON Patch - http://tools.ietf.org/html/rfc6902
• JSON Pointer - http://tools.ietf.org/html/rfc6901
• Extensions (to be documented):
  • wildcard references
  • attribute lookahead
  • lax mode

Methods

jsonpatch.apply(document, patch, lax=true)

Applies a patch set to the document. The last parameter enables lax mode, in which the following modifications are made to the JSONPatch algorithm:

• The add operation adjusts out-of-bounds array indices down to the array length.
• The replace operation works even when the source location does not exist: for objects the new key is created, and for arrays the item is inserted at the end.
• Any other conflicting patches are silently ignored instead of aborting the operation.

jsonpatch.compile(patch)

Compiles a patch set and returns a function that takes a document to apply the patch set to.

Patch Operations

Add

Patch syntax: {op: 'add', path: <path>, value: <value>}

// Add property, result: {foo: 'bar'}
jsonpatch.apply({}, [{op: 'add', path: '/foo', value: 'bar'}]);

// Add array element, result: {foo: [1, 2, 3]}
jsonpatch.apply({foo: [1, 3]}, [{op: 'add', path: '/foo/1', value: 2}]);

// Complex, result: {foo: [{bar: 'baz'}]}
jsonpatch.apply({foo: [{}]}, [{op: 'add', path: '/foo/0/bar', value: 'baz'}]);

Remove

Patch syntax: {op: 'remove', path: <path>}

// Remove property, result: {}
jsonpatch.apply({foo: 'bar'}, [{op: 'remove', path: '/foo'}]);

// Remove array element, result: {foo: [1, 3]}
jsonpatch.apply({foo: [1, 2, 3]}, [{op: 'remove', path: '/foo/1'}]);

// Complex, result: {foo: [{}]}
jsonpatch.apply({foo: [{bar: 'baz'}]}, [{op: 'remove', path: '/foo/0/bar'}]);

Replace

Patch syntax: {op: 'replace', path: <path>, value: <value>}

// Replace property, result: {foo: 1}
jsonpatch.apply({foo: 'bar'}, [{op: 'replace', path: '/foo', value: 1}]);

// Repalce array element, result: {foo: [1, 4, 3]}
jsonpatch.apply({foo: [1, 2, 3]}, [{op: 'replace', path: '/foo/1', value: 4}]);

// Complex, result: {foo: [{bar: 1}]}
jsonpatch.apply({foo: [{bar: 'baz'}]}, [{op: 'replace', path: '/foo/0/bar', value: 1}]);

Move

Patch syntax: {op: 'move', from: <path>, path: <path>}

// Move property, result {bar: [1, 2, 3]}
jsonpatch.apply({foo: [1, 2, 3]}, [{op: 'move', from: '/foo', path: '/bar'}]);

Copy

Patch syntax: {op: 'copy', from: <path>, path: <path>}

// Copy property, result {foo: [1, 2, 3], bar: 2}
jsonpatch.apply({foo: [1, 2, 3]}, [{op: 'copy', from: '/foo/1', path: '/bar'}]);

Test

Patch syntax: {op: 'test', path: <path>, value: <value>}

// Test equality of property to value, result: {foo: 'bar'}
jsonpatch.apply({foo: 'bar'}, [{op: 'test', path: '/foo', value: 'bar'}]

Error Types

JSONPatchError

Base error type which all patch errors extend from.

InvalidPointerError

Thrown when the pointer is invalid.

InvalidPatchError

Thrown when the patch itself has an invalid syntax.

PatchConflictError

Thrown when there is a conflic with applying the patch to the document.