PetaJson/Topten.JsonKit/JsonAttribute.cs

// JsonKit v0.5 - A simple but flexible Json library in a single .cs file.
// 
// Copyright (C) 2014 Topten Software (contact@toptensoftware.com) All rights reserved.
// 
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this product 
// except in compliance with the License. You may obtain a copy of the License at
// 
// http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software distributed under the 
// License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
// either express or implied. See the License for the specific language governing permissions 
// and limitations under the License.

using System;

namespace Topten.JsonKit
{
    // Used to decorate fields and properties that should be serialized
    //
    // - [Json] on class or struct causes all public fields and properties to be serialized
    // - [Json] on a public or non-public field or property causes that member to be serialized
    // - [JsonExclude] on a field or property causes that field to be not serialized
    // - A class or struct with no [Json] attribute has all public fields/properties serialized
    // - A class or struct with no [Json] attribute but a [Json] attribute on one or more members only serializes those members
    //
    // Use [Json("keyname")] to explicitly specify the key to be used 
    // [Json] without the keyname will be serialized using the name of the member with the first letter lowercased.
    //
    // [Json(KeepInstance=true)] causes container/subobject types to be serialized into the existing member instance (if not null)
    //
    // You can also use the system supplied DataContract and DataMember attributes.  They'll only be used if there
    // are no JsonKit attributes on the class or it's members. You must specify DataContract on the type and
    // DataMember on any fields/properties that require serialization.  There's no need for exclude attribute.
    // When using DataMember, the name of the field or property is used as is - the first letter is left in upper case
    //
    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Property | AttributeTargets.Field)]
    public class JsonAttribute : Attribute
    {
        public JsonAttribute()
        {
            _key = null;
        }

        public JsonAttribute(string key)
        {
            _key = key;
        }

        // Key used to save this field/property
        string _key;
        public string Key
        {
            get { return _key; }
        }

        // If true uses ParseInto to parse into the existing object instance
        // If false, creates a new instance as assigns it to the property
        public bool KeepInstance
        {
            get;
            set;
        }

        // If true, the property will be loaded, but not saved
        // Use to upgrade deprecated persisted settings, but not
        // write them back out again
        public bool Deprecated
        {
            get;
            set;
        }
    }
}