anegostudios / Tavis.JsonPatch

Tavis.JsonPatch

This library is (mostly) an implementation of a Json Patch RFC 6902.

Differences from the RFC 6902:

• The add op performs a merge if the target is an object
• New addreplace op implements the original add behavior.
• New addeach op to add multiple values to an array

The default example from the specification looks like this,

[
     { "op": "test", "path": "/a/b/c", "value": "foo" },
     { "op": "remove", "path": "/a/b/c" },
     { "op": "add", "path": "/a/b/c", "value": ["foo", "bar"] },
     { "op": "replace", "path": "/a/b/c", "value": 42 },
     { "op": "move", "from": "/a/b/c", "path": "/a/b/d" },
     { "op": "copy", "from": "/a/b/d", "path": "/a/b/e" }
]

This library allows you to create this document by doing,

   var patchDoc = new PatchDocument( new Operation[]
        {
         new TestOperation() {Path = new JsonPointer("/a/b/c"), Value = new JValue("foo")}, 
         new RemoveOperation() {Path = new JsonPointer("/a/b/c") }, 
         new AddOperation() {Path = new JsonPointer("/a/b/c"), Value = new JArray(new JValue("foo"), new JValue("bar"))}, 
         new ReplaceOperation() {Path = new JsonPointer("/a/b/c"), Value = new JValue(42)}, 
         new MoveOperation() {FromPath = new JsonPointer("/a/b/c"), Path = new JsonPointer("/a/b/d") }, 
         new CopyOperation() {FromPath = new JsonPointer("/a/b/d"), Path = new JsonPointer("/a/b/e") }, 
        });

This document can be serialized to the wire format like this,

     var outputstream = patchDoc.ToStream();

You can also read patch documents from the wire representation and apply them to a JSON document.

    var targetDoc = JToken.Parse("{ 'foo': 'bar'}");
    var patchDoc = PatchDocument.Parse(@"[
                  { 'op': 'add', 'path': '/baz', 'value': 'qux' }
                ]");

    patchDoc.ApplyTo(targetDoc);

    Assert.True(JToken.DeepEquals(JToken.Parse(@"{
                                                     'foo': 'bar',
                                                     'baz': 'qux'
                                                   }"), targetDoc));

You can also apply the Json patch format to other targets by implementing the IPatchTarget interface.

The unit tests provide examples of other usages.

This library is a PCL based library and so will work on Windows 8, Windows Phone 7.5, .Net 4.

A nuget package is available here.