using System;

using System.Runtime.Serialization;

namespace ReactiveUI.Serialization

{

#if WINDOWS_PHONE

/// <summary>

/// ModelBase represents the base implementation of ISerializableItem and

/// handles a lot of the infrastructure plumbing around maintaining the

/// Content Hash.

///

/// For objects who are frequently serialized/deserialized, derived classes

/// should override CalculateHash and implement it in a more specific

/// manner.

/// </summary>

[DataContract]

public abstract class ModelBase : ReactiveObject, ISerializableItem

#else

/// <summary>

/// ModelBase represents the base implementation of ISerializableItem and

/// handles a lot of the infrastructure plumbing around maintaining the

/// Content Hash.

///

/// For objects who are frequently serialized/deserialized, derived classes

/// should override CalculateHash and implement it in a more specific

/// manner.

/// </summary>

[DataContract]

public abstract class ModelBase : ReactiveValidatedObject, ISerializableItem

#endif

{

static Guid inProgressGuid = new Guid(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1);

[IgnoreDataMember] Guid _ContentHash;

[IgnoreDataMember]

public Guid ContentHash {

get {

if (_ContentHash == Guid.Empty) {

// XXX: This is a blatant hack to make sure that the JSON serializer

// doesn't end up recursively calling CalculateHash

_ContentHash = inProgressGuid;

_ContentHash = CalculateHash();

}

return _ContentHash;

}

protected set { _ContentHash = value; }

}

public ModelBase()

{

setupModelBase();

}

[OnDeserialized]

void setupModelBase(StreamingContext sc) { setupModelBase(); }

void setupModelBase()

{

this.Log().InfoFormat("Deserialized ModelBase 0x{0:X}", this.GetHashCode());

Changed.Subscribe(_ => invalidateHash());

invalidateHash();

}

public virtual Guid CalculateHash()

{

return new Guid(this.ObjectContentsHash());

}

protected virtual void invalidateHash()

{

ContentHash = Guid.Empty;

}

}

}

// vim: tw=120 ts=4 sw=4 et :