/MySpaceSilverlight/MySpaceSilverlightKit/AppData.cs

// <copyright file="AppData.cs" company="Microsoft Corporation">

// Copyright (c) 2009 Microsoft Corporation All Rights Reserved

// </copyright>

// <author>Michael S. Scherotter</author>

// <email>mischero@microsoft.com</email>

// <date>2009-05-28</date>

// <summary>Application Data</summary>



namespace MyOpenSpace

{

    using System.ComponentModel;

    using System.Globalization;

    using System.Windows.Browser;

    using opensocial;

    using Synergist;    

    

    /// <summary>

    /// User Application data

    /// </summary>

    /// <remarks>Uses the <a target="_blank" 

    /// href="http://wiki.opensocial.org/index.php?title=The_Persistence_API">

    /// OpenSocial Persistance API</a></remarks>

    public class AppData : INotifyPropertyChanged

    {

        #region Fields

        /// <summary>

        /// the app value stored

        /// </summary>

        private string appValue;



        /// <summary>

        /// the key to the app value

        /// </summary>

        private string key;



        /// <summary>

        /// the ID of the user (default is "opensocial.IdSpec.PersonId.VIEWER")

        /// </summary>

        private string id;



        /// <summary>

        /// the opensocial object

        /// </summary>

        private ScriptObject opensocial;

        #endregion



        #region Constructors

        /// <summary>

        /// Initializes a new instance of the AppData class.

        /// </summary>

        public AppData()

        {

            this.id = "opensocial.IdSpec.PersonId.VIEWER";

        }

        #endregion



        #region INotifyPropertyChanged Members



        /// <summary>

        /// Property changed event handler

        /// </summary>

        public event PropertyChangedEventHandler PropertyChanged;



        #endregion



        #region Properties

        /// <summary>

        /// Gets the opensocial object

        /// </summary>

        public ScriptObject OpenSocial

        {

            get

            {

                if (this.opensocial == null)

                {

                    try

                    {

                        this.opensocial = HtmlPage.Window.Eval("opensocial") as ScriptObject;

                    }

                    catch (System.InvalidOperationException ioe)

                    {

                        System.Diagnostics.Debug.WriteLine("Not running in an OpenSocial container: {0}", ioe.Message);



                        return null;

                    }

                }



                return this.opensocial;

            }

        }



        /// <summary>

        /// Gets or sets the user to read/write persistent data for

        /// </summary>

        public string Id

        {

            get

            {

                return this.id;

            }



            set

            {

                if (this.id != value)

                {

                    this.id = value;

                }

            }

        }



        /// <summary>

        /// Gets or sets the app data key

        /// </summary>

        public string Key

        {

            get

            {

                return this.key;

            }



            set

            {

                if (this.key != value)

                {

                    this.key = value;



                    this.SetValue();

                }

            }

        }



        /// <summary>

        /// Gets or sets the app data value

        /// </summary>

        public string Value

        {

            get

            {

                if (string.IsNullOrEmpty(this.appValue))

                {

                    this.FetchValue();

                }



                return this.appValue;

            }



            set

            {

                if (this.appValue != value)

                {

                    this.appValue = value;



                    this.SetValue();

                }

            }

        }

        #endregion



        #region Methods



        /// <summary>

        /// remove the key value

        /// </summary>

        public void RemoveValue()

        {

            if (this.OpenSocial == null)

            {

                return;

            }



            var dataRequest = new DataRequest(this.OpenSocial.Invoke("newDataRequest", null) as ScriptObject);



            var request = dataRequest.newRemovePersonAppDataRequest(this.Id, this.Key);



            dataRequest.add(request, this.Id.Eval());



            dataRequest.send(new opensocial.DataReceived(this.OnDataRemoved));

        }



        #endregion



        #region Implementation



        /// <summary>

        /// Fetch the value from persistent storage

        /// </summary>

        private void FetchValue()

        {

            if (this.OpenSocial == null)

            {

                return;

            }



            var dataRequest = new DataRequest(this.OpenSocial.Invoke("newDataRequest", null) as ScriptObject);



            var idSpec = new IdSpec()

            {

                UserId = this.Id.Eval()

            };



            var request = dataRequest.newFetchPersonAppDataRequest(idSpec, this.Key, null);



            dataRequest.add(request, "get_data");



            dataRequest.send(new opensocial.DataReceived(this.OnDataRetrieved));

        }



        /// <summary>

        /// Set the value to persistent storage

        /// </summary>

        private void SetValue()

        {

            if (string.IsNullOrEmpty(this.Key) || string.IsNullOrEmpty(this.Value))

            {

                return;

            }



            if (this.OpenSocial == null)

            {

                return;

            }



            var dataRequest = new DataRequest(this.OpenSocial.Invoke("newDataRequest", null) as ScriptObject);



            string jsonValue = "{" + string.Format(

                CultureInfo.InvariantCulture, 

                "\"{0}\" : \"{1}\"", 

                this.Key, 

                this.Value) + "}";



            var request = dataRequest.newUpdatePersonAppDataRequest(this.Id, this.Key, jsonValue);



            dataRequest.add(request, "set_data");



            dataRequest.send(new opensocial.DataReceived(this.OnDataUpdated));

        }



        /// <summary>

        /// Data updated event handler

        /// </summary>

        /// <param name="response">the data response</param>

        private void OnDataUpdated(DataResponse response)

        {

            if (response.HadError)

            {

            }

            else

            {

                var data = response.get("set_data").getData();

            }

        }

        

        /// <summary>

        /// Data retrieved event handler

        /// </summary>

        /// <param name="response">the data response</param>

        private void OnDataRetrieved(DataResponse response)

        {

            if (response.HadError)

            {

            }

            else

            {

                var data = response.get("get_data").getData();



                var viewerId = HtmlPage.Window.Eval("gadgets.views.getParams().viewerId") as string;



                var viewerData = data.GetProperty(viewerId) as ScriptObject;



                if (viewerData != null)

                {

                    var property = viewerData.GetProperty(this.Key) as ScriptObject;



                    if (property != null)

                    {

                        this.appValue = property.GetProperty(this.Key) as string;



                        if (this.PropertyChanged != null)

                        {

                            this.PropertyChanged(this, new PropertyChangedEventArgs("Value"));

                        }

                    }

                }

            }

        }



        /// <summary>

        /// Data removed event handler

        /// </summary>

        /// <param name="response">the data response</param>

        private void OnDataRemoved(DataResponse response)

        {

        }



        #endregion

    }

}