/// <summary>
/// Retrieves an object from the data source of the specified type with the specified primary key.
/// </summary>
/// <remarks>
/// Selects a single object from the data source using the given key to locate the values. If no values exist in the data source then Select returns null.
/// <para>
/// The actual objects returned from a call to Select are not of the defined type but of a
/// proxy class which sub-classes the persisted object and implements the abstract properties.
/// This is transparent as long as no access to the type occurs. If this is done then it is
/// nessecary to access the proxy's base type to get back to the defined type.
/// </para>
/// </remarks>
/// <param name="type">The type of object to create.</param>
/// <param name="key">The primary key which to select the object in the data source.</param>
/// <returns>A newly initialised proxy for the specified type and with the values given from the data source for the specified primary key.</returns>
public ServerObject Select(Type type, object key)
{
if (type == null)
{
throw new ArgumentNullException("type", "type cannot be null.");
}
if (key == null)
{
return(null);
}
Trace.WriteLineIf(DebugOutput.Enabled, "Selecting ServerObject of type " + type.FullName);
ServerObject obj = objectCache.Get(type, key);
if (obj != null)
{
return(obj);
}
try
{
adapter.Open();
obj = adapter.Select(type, key);
}
finally
{
adapter.Close();
}
if (obj == null)
{
Trace.WriteLineIf(DebugOutput.Enabled, "No object found returning null");
return(null);
}
obj.State = ObjectState.Unchanged;
obj.SetTransaction(this);
objectCache.Add(obj);
obj.PromptEvent(EventType.Initialised);
return(obj);
}
private void CommitChildren(ServerObject obj, object key)
{
Trace.WriteLineIf(DebugOutput.Enabled, "Enumerating children");
TypeSchema schema = SchemaCache.Current.GetSchema(obj.ServerObjectType);
if (key != null)
{
foreach (ChildrenSchema childSchema in schema.ChildrenSchemas)
{
ServerObjectCollection children = obj.Children.GetValue(childSchema.Property.Name);
if (children == null)
{
continue;
}
TypeSchema childTypeSchema = SchemaCache.Current.GetSchema(childSchema.ChildType);
ParentSchema parentSchema = childTypeSchema.FindParentSchema(childSchema.PropertyName);
foreach (ServerObject child in children)
{
if (child.Parents.GetValue(parentSchema.Property.Name) != obj)
{
continue;
}
child.Data.SetValue(parentSchema.Property.Name, key);
}
}
}
foreach (ChildrenSchema childSchema in schema.ChildrenSchemas)
{
ServerObjectCollection children = obj.Children.GetValue(childSchema.Property.Name);
if (children == null)
{
continue;
}
foreach (ServerObject child in children)
{
Commit(child, true);
}
}
}
public ServerObject Add(ServerObject obj)
{
Type type = obj.ServerObjectType;
TypeSchema schema = SchemaCache.Current.GetSchema(type);
object key = obj.Data.GetValue(schema.PrimaryKey.Property.Name);
Trace.WriteLineIf(DebugOutput.Enabled, "Adding object with key " + key.ToString());
if (objectCache.ContainsKey(key))
{
Trace.WriteLineIf(DebugOutput.Enabled, "Object already in cache, returning orginal");
return(objectCache[key] as ServerObject);
}
Trace.WriteLineIf(DebugOutput.Enabled, "Adding object to cache");
objectCache.Add(key, obj);
return(obj);
}
internal ServerObjectCollection SelectChildren(ServerObject obj, string propertyName)
{
Trace.WriteLineIf(DebugOutput.Enabled, "Selecting children for " + propertyName);
TypeSchema schema = SchemaCache.Current.GetSchema(obj.ServerObjectType);
ChildrenSchema childrenSchema = schema.FindChildrenSchema(propertyName);
ServerObjectCollection children = null;
object primaryKey = obj.Data.GetValue(schema.PrimaryKey.Property.Name);
Query query = new Query(new Condition(childrenSchema.PropertyName, Expression.Equal, primaryKey));
children = Select(childrenSchema.ChildType, query);
Trace.WriteLineIf(DebugOutput.Enabled, "Checking cache for more items");
foreach (ServerObject cacheItem in objectCache.GetCacheItem(childrenSchema.ChildType))
{
if (primaryKey.Equals(cacheItem.Data.GetValue(childrenSchema.PropertyName)) && !children.Contains(cacheItem))
{
children.Add(cacheItem);
}
}
ServerObjectCollection toRemove = new ServerObjectCollection();
foreach (ServerObject child in children)
{
if (!primaryKey.Equals(child.Data.GetValue(childrenSchema.PropertyName)))
{
toRemove.Add(child);
}
}
foreach (ServerObject child in toRemove)
{
children.Remove(child);
}
return(children);
}
public ServerObject Add(ServerObject obj)
{
Type type = obj.ServerObjectType;
Trace.WriteLineIf(DebugOutput.Enabled, "Adding object of type " + type.FullName);
if (typeCache.ContainsKey(type.FullName))
{
Trace.WriteLineIf(DebugOutput.Enabled, "CacheItem found");
CacheItem CacheItem = typeCache[type.FullName] as CacheItem;
return(CacheItem.Add(obj));
}
else
{
Trace.WriteLineIf(DebugOutput.Enabled, "Creating new CacheItem");
CacheItem CacheItem = new CacheItem();
typeCache.Add(type.FullName, CacheItem);
return(CacheItem.Add(obj));
}
}
/// <summary>
/// Marks a object for removal in the transaction.
/// </summary>
/// <remarks>
/// This method can take a lengthy time dependent on its position in the relational graph due to having to
/// traverse an object's child objects and either delete or set to null.
/// <para>
/// If the object graph traversal encounters an child relation with at least one valid object and ActionOnDelete is
/// <see cref="DeleteAction.Throw">DeleteAction.Throw</see> then an <see cref="ObjectServerException">ObjectServerException</see>
/// will be thrown. It is likely that the object graph will be left in an invalid state and it is not advised to <see cref="ObjectTransaction.Commit">Commit</see>
/// the transaction.
/// </para>
/// </remarks>
/// <param name="obj">The object to be marked for removal.</param>
public void Delete(ServerObject obj)
{
if (obj == null)
{
throw new ArgumentNullException("obj", "obj cannot be null.");
}
Trace.WriteLineIf(DebugOutput.Enabled, "Deleting object of type " + obj.ServerObjectType);
DeleteImpl(obj);
Trace.WriteLineIf(DebugOutput.Enabled, "Clearing Processed Objects");
foreach (CacheItem cacheItem in objectCache)
{
foreach (ServerObject item in cacheItem)
{
item.Processed = false;
}
}
}
internal ObjectData(ServerObject obj)
{
Trace.WriteLineIf(DebugOutput.Enabled, "Initialising ObjectData");
this.obj = obj;
data = new Hashtable();
}
/// <summary>
/// Gets or sets the <see cref="ServerObject">ServerObject</see> that is a Parent object.
/// </summary>
/// <remarks>
/// On object access if a parent exists but has not be retrieved by ObjectServer then it will be retrieved and returned.
/// Otherwise the existing object will be returned. If you wish a null value to be set the assign null to the parent.
/// When an object is assigned as a parent, ObjectServer will locate the correct children collection and automatically append the current object.
/// </remarks>
/// <param name="key">The name of the property in the <see cref="ServerObject">ServerObject</see> which exposes this Parent.</param>
/// <value>A <see cref="ServerObject">ServerObject</see> that is a Parent object or if no parent exists null.</value>
public ServerObject this[string key]
{
get
{
if (data[key] == null)
{
Trace.WriteLineIf(DebugOutput.Enabled, "Parent not found, loading");
TypeSchema schema = SchemaCache.Current.GetSchema(obj.ServerObjectType);
ParentSchema parentSchema = schema.FindParentSchema(key);
ServerObject parent = obj.Transaction.Select(parentSchema.Property.PropertyType, obj.Data.GetValue(key));
data[key] = parent;
return(parent);
}
else if (Convert.IsDBNull(data[key]))
{
Trace.WriteLineIf(DebugOutput.Enabled, "Key Value is DBNull.Value returning null");
return(null);
}
return(data[key] as ServerObject);
}
set
{
if (value == null)
{
Trace.WriteLineIf(DebugOutput.Enabled, "Parent set to null, setting key value to DBNull.Value");
obj.Data.SetValue(key, DBNull.Value);
data[key] = DBNull.Value;
UpdateState(key);
}
else
{
if (!value.Equals(data[key]))
{
Trace.WriteLineIf(DebugOutput.Enabled, "New Parent set");
ServerObject newParent = value as ServerObject;
ServerObject oldParent = data[key] != null ? data[key] as ServerObject : null;
TypeSchema schema = SchemaCache.Current.GetSchema(newParent.ServerObjectType);
object parentKey = newParent.Data.GetValue(schema.PrimaryKey.Property.Name);
obj.Data.SetValue(key, parentKey);
data[key] = newParent;
UpdateState(key);
foreach (ChildrenSchema childSchema in schema.ChildrenSchemas)
{
if (childSchema.PropertyName == key && childSchema.ChildType == obj.ServerObjectType)
{
if (oldParent != null)
{
Trace.WriteLineIf(DebugOutput.Enabled, "Removing from children collection " + childSchema.Property.Name);
ServerObjectCollection oldChildren = oldParent.Children.GetValue(childSchema.Property.Name);
if (oldChildren != null && oldChildren.Contains(obj))
{
oldChildren.Remove(obj);
}
}
Trace.WriteLineIf(DebugOutput.Enabled, "Adding to children collection " + childSchema.Property.Name);
ServerObjectCollection newChildren = newParent.Children.GetValue(childSchema.Property.Name);
if (newChildren != null && !newChildren.Contains(obj))
{
newChildren.Add(obj);
}
break;
}
}
}
}
}
}
/// <summary>
/// Inserts the specified <see cref="ServerObject">ServerObject</see> into the collection at the specified index.
/// </summary>
/// <param name="index">The zero-based index where the specified object should be inserted.</param>
/// <param name="obj">The <see cref="ServerObject">ServerObject</see> to insert. </param>
public void Insert(int index, ServerObject obj)
{
List.Insert(index, obj);
}
/// <summary>
/// Gets the index in the collection of the specified <see cref="ServerObject">ServerObject</see>, if it exists in the collection.
/// </summary>
/// <param name="obj">The <see cref="ServerObject">ServerObject</see> to locate in the collection.</param>
/// <returns>The index in the collection of the specified object, if found; otherwise, -1.</returns>
public int IndexOf(ServerObject obj)
{
return(List.IndexOf(obj));
}
/// <summary>
/// Gets a value indicating whether the collection contains the specified <see cref="ServerObject">ServerObject</see>.
/// </summary>
/// <param name="obj">The <see cref="ServerObject">ServerObject</see> to search for in the collection. </param>
/// <returns><see langword="true">true</see> if the collection contains the specified object; otherwise, <see langword="false">false</see>.</returns>
public bool Contains(ServerObject obj)
{
return(List.Contains(obj));
}
/// <summary>
/// Removes the specified <see cref="ServerObject">ServerObject</see> from the collection.
/// </summary>
/// <param name="obj">The <see cref="ServerObject">ServerObject</see> to remove from the collection.</param>
/// <exception cref="ArgumentException">
/// The specified object is not found in the collection.
/// </exception>
public void Remove(ServerObject obj)
{
List.Remove(obj);
}
/// <summary>
/// Adds the specified <see cref="ServerObject">ServerObject</see> to the collection.
/// </summary>
/// <param name="obj">The <see cref="ServerObject">ServerObject</see> to add.</param>
/// <returns>The index at which the new element was inserted.</returns>
public int Add(ServerObject obj)
{
return(List.Add(obj));
}
internal bool Commit(ServerObject obj, bool ignoreVisited)
{
if (obj.Processed)
{
return(true);
}
if (obj.Visited && !ignoreVisited)
{
return(false);
}
Trace.WriteLineIf(DebugOutput.Enabled, "Commiting ServerObject of type " + obj.ServerObjectType);
TypeSchema schema = SchemaCache.Current.GetSchema(obj.ServerObjectType);
obj.Visited = true;
switch (obj.State)
{
case ObjectState.Added:
obj.PromptEvent(EventType.Validate);
if (!CommitParents(obj))
{
break;
}
if (!obj.Processed)
{
Trace.WriteLineIf(DebugOutput.Enabled, "Inserting ServerObject of type " + obj.ServerObjectType);
adapter.Insert(obj);
obj.Processed = true;
}
CommitChildren(obj, obj.Data.GetValue(schema.PrimaryKey.Property.Name));
obj.State = ObjectState.Unchanged;
break;
case ObjectState.Deleted:
CommitChildren(obj, null);
Trace.WriteLineIf(DebugOutput.Enabled, "Deleting ServerObject of type " + obj.ServerObjectType);
obj.PromptEvent(EventType.Deleted);
adapter.Delete(obj);
obj.Processed = true;
CommitParents(obj);
obj.State = ObjectState.Detached;
break;
case ObjectState.Modified:
obj.PromptEvent(EventType.Validate);
if (!CommitParents(obj))
{
break;
}
if (!obj.Processed)
{
Trace.WriteLineIf(DebugOutput.Enabled, "Updating ServerObject of type " + obj.ServerObjectType);
adapter.Update(obj);
obj.Processed = true;
}
CommitChildren(obj, obj.Data.GetValue(schema.PrimaryKey.Property.Name));
obj.State = ObjectState.Unchanged;
break;
case ObjectState.Unchanged:
case ObjectState.Detached:
obj.Processed = true;
break;
default:
throw new ObjectServerException("Invalid ObjectState found.");
}
;
return(obj.Processed);
}
private void DeleteImpl(ServerObject obj)
{
if (obj.Processed)
{
return;
}
Trace.WriteLineIf(DebugOutput.Enabled, "Deleting ServerObject of type " + obj.ServerObjectType);
switch (obj.State)
{
case ObjectState.Added:
Trace.WriteLineIf(DebugOutput.Enabled, "Setting state to ObjectState.Detached");
obj.State = ObjectState.Detached;
break;
case ObjectState.Modified:
case ObjectState.Unchanged:
Trace.WriteLineIf(DebugOutput.Enabled, "Setting state to ObjectState.Deleted");
obj.State = ObjectState.Deleted;
break;
case ObjectState.Deleted:
case ObjectState.Detached:
break;
default:
throw new ObjectServerException("Invalid ObjectState found.");
}
;
obj.Processed = true;
TypeSchema parentTypeSchema = SchemaCache.Current.GetSchema(obj.ServerObjectType);
Trace.WriteLineIf(DebugOutput.Enabled, "Enumerating Childrean");
foreach (ChildrenSchema childSchema in parentTypeSchema.ChildrenSchemas)
{
Trace.WriteLineIf(DebugOutput.Enabled, "Checking Children " + childSchema.Property.Name);
ServerObjectCollection children = obj.Children[childSchema.Property.Name] as ServerObjectCollection;
TypeSchema childTypeSchema = SchemaCache.Current.GetSchema(childSchema.ChildType);
ParentSchema parentSchema = childTypeSchema.FindParentSchema(childSchema.PropertyName);
int nonDeleted = 0;
foreach (ServerObject child in children)
{
if (child.State != ObjectState.Deleted && child.State != ObjectState.Detached)
{
nonDeleted++;
}
}
Trace.WriteLineIf(DebugOutput.Enabled, "Counted " + nonDeleted + " non-deleted children");
if (nonDeleted > 0)
{
if (parentSchema.DeleteAction == DeleteAction.Throw)
{
throw new ObjectServerException(String.Format(CultureInfo.CurrentCulture, "Could not delete, {0}.{1} has DeleteAction.Throw", childTypeSchema.Type.FullName, parentSchema.Property.Name));
}
if (parentSchema.DeleteAction == DeleteAction.Null)
{
Trace.WriteLineIf(DebugOutput.Enabled, "Changing key to DBNull.Value and updating state");
foreach (ServerObject child in children)
{
child.Data.SetValue(childSchema.PropertyName, DBNull.Value);
switch (child.State)
{
case ObjectState.Added:
case ObjectState.Modified:
case ObjectState.Detached:
case ObjectState.Deleted:
break;
case ObjectState.Unchanged:
child.State = ObjectState.Modified;
break;
default:
throw new ObjectServerException("Invalid ObjectState found.");
}
;
}
continue;
}
}
Trace.WriteLineIf(DebugOutput.Enabled, "Processing children");
foreach (ServerObject child in children)
{
DeleteImpl(child);
}
}
}
