UniRapidJSON

UniRapidJSON is RapidJSON wrapper for Unity.

UniRapidJSON does not extend mono's heap memory.
Because RapidJSON uses native memory to parse JSON strings.

Supported Platforms: iOS, Android, Windows, OSX
Experimental Supported: WinRT

UniRapidJSON currently only supports JSON Parser and JOIN Pointer.
Note that, Writable functions are not supported.

Tutorial

UniRapidJSON implements the RapidJSON like interface.
Let's challenge Tutorial of RapidJSON with UniRapidJSON.

Query Value

There is the following JSON string stored in string:

{
    "hello": "world",
    "t": true ,
    "f": false,
    "n": null,
    "i": 123,
    "pi": 3.1416,
    "a": [1, 2, 3, 4]
}

Parse it into a Document:

using rapidjson;

// ...
using (var document = Document.Parse(json)) {
    // rapidjson.Document inherits the System.IDisposable interface.
}

Let's query whether a "hello" member exists in the root object. Since a Value can contain different types of value, we may need to verify its type and use suitable API to obtain the value. In this example, "hello" member associates with a JSON string.

Assert.IsTrue(document.Root.HasMember("hello"));
Assert.IsTrue(document.Root["hello"].IsString());
Debug.Log(string.Format("hello = {0}", document.Root["hello"].ToString()));

hello = world

JSON true/false values are represented as bool.

Assert.IsTrue(document.Root["t"].IsBool());
Debug.Log(string.Format("t = {0}", document.Root["t"].ToBool() ? "true" : "false"));

t = true

JSON null can be queried with IsNull().

Debug.Log(string.Format("n = {0}", document.Root["n"].IsNull() ? "null" : "?"));

n = null

JSON number type represents all numeric values. However, C# needs more specific type for manipulation.

Assert.IsTrue(document.Root["i"].IsNumber());

// In this case, IsUint()/IsLong()/IsULong() also return true.
Assert.IsTrue(document.Root["i"].IsInt());          
Debug.Log(string.Format("i = {0}", document.Root["i"].ToInt()));
// Alternative (int)document.Root["i"]

Assert.IsTrue(document.Root["pi"].IsNumber());
Assert.IsTrue(document.Root["pi"].IsDouble());
Debug.Log(string.Format("pi = {0}", document.Root["pi"].ToDouble()));

i = 123
pi = 3.1416

JSON array contains a number of elements.

var a = document.Root["a"];
Assert.IsTrue(a.IsArray());
for (int i = 0; i < a.Size(); i++) 
    Debug.Log(string.Format("a[{0}] = {1}", i, a[i].ToInt()));

a[0] = 1
a[1] = 2
a[2] = 3
a[3] = 4

Note that, RapidJSON does not automatically convert values between JSON types. If a value is a string, it is invalid to call ToInt(), for example. In debug mode it will fail an assertion. In release mode, the behavior is undefined.

In the following sections we discuss details about querying individual types.

Query Array

You may access the elements in an array by integer literal, for example, a[0], a[1], a[2].
Array is inherits IEnumerable: instead of using indices, you may also use foreach statement to access all the elements.

foreach (var value in a.GetArray()) 
    Debug.Log(string.Format("{0}", value.ToInt()));

Query Object

Similar to Array, we can access all object members by foreach statement:

foreach (var member in document.Root.GetObject())
    Debug.Log(string.Format("Type of member {0} is {1}",
        member.Key, member.Value.GetValueType()));

Note that, when this[string]: indexer cannot find the member, it will throw an KeyNotFoundException.

If we are unsure whether a member exists, we need to call HasMember() before calling this[string]: indexer. However, this incurs two lookup. A better way is to call TryGetValue(), which can check the existence of member and obtain its value at once:

var root = document.Root.GetObject();
Value value;
if (root.TryGetValue("hello", out value))
    Debug.Log(value.ToString());

JSON Pointer

A JSON Pointer is a list of zero-to-many tokens, each prefixed by /. Each token can be a string or a number. For example, given a JSON:

{
    "foo" : ["bar", "baz"],
    "pi" : 3.1416
}

The following JSON Pointers resolve this JSON as:

• "/foo" → [ "bar", "baz" ]
• "/foo/0" → "bar"
• "/foo/1" → "baz"
• "/pi" → 3.1416

Note that, an empty JSON Pointer "" (zero token) resolves to the whole JSON.

Usage JSON Pointer

Value a;
if (document.Root.TryGetValueByPointer("/foo", out a)) 
    foreach (var v in a.GetArray()) 
        Debug.Log(v.ToString());

Debug.Log(document.Root.GetValueByPointer("/foo/0", "default string"));
Debug.Log(document.Root.GetValueByPointer("/foo/1", "default string"));
Debug.Log("" + document.Root.GetValueByPointer("/pi", 0.0));

bar
baz
bar
baz
3.1416

LICENSE

UniRapidJSON is released under the MIT license, see LICENSE.

Thanks for RapidJSON contributors.