/// <summary>
/// Instantiates the class using default components
/// </summary>
/// <param name="dbContext">Context in which to perform the merge operation</param>
/// <param name="modelsNamespace">Namespace in which all context entities are defined (all models must be within
/// the same namespace. If model type is in a different namespace, an exception will be thrown when instantiating
/// the type. This is, hopefully, a temporary workaround, until I find a good solution for this)</param>
/// <param name="modelAssemblyName">Name of assembly which contains all context enties. Again, just like with the
/// namespace parameter, this is a temporary workaround</param>
public DefaultEntityChangesMerger(DbContext dbContext, string modelsNamespace, string modelAssemblyName)
{
DbContext = dbContext;
reflector = new DbContextReflector(DbContext, modelsNamespace, modelAssemblyName);
scalarUpdater = new ScalarPropertyUpdater(DbContext, reflector);
entityComparer = new EntityComparerByNonForeignKeys();
collectionMerger = new CollectionMerger(entityComparer);
navUpdater = new NavigationPropertyUpdater(DbContext, scalarUpdater, reflector);
}
public TEntity UpdateEntity <TEntity>(TEntity model, IRecursiveEntityUpdater updater)
where TEntity : class
{
// Update scalar properties
TEntity updatedModel = UpdateEntity <TEntity>(model);
UpdateAllNavigationProperties(updatedModel, model, updater, updatedModel == model);
return(updatedModel);
}
/*public void UpdateCollection(Expression<Func<TModel, IList<TCollectionEntry>>> property, object sourceModel)
* {
* MemberExpression mex = (MemberExpression)property.Body;
* UpdateCollection((PropertyInfo)mex.Member, sourceModel);
* }*/
public void UpdateCollection <TCollectionEntry>(IDbContextReflector reflector, NavigationPropertyInfo property,
object sourceModel, bool modelIsNew, IRecursiveEntityUpdater entityUpdater)
where TCollectionEntry : class
{
Reflector = reflector;
Property = property;
EntityUpdater = entityUpdater;
if (modelIsNew)
{
AddCollection((IList <TCollectionEntry>)property.PropertyInfo.GetValue(sourceModel));
}
else
{
UpdateCollection((IList <TCollectionEntry>)property.PropertyInfo.GetValue(Model),
(IList <TCollectionEntry>)property.PropertyInfo.GetValue(sourceModel));
}
}
protected override void UpdateAllNavigationProperties <TEntity>(TEntity updatedModel, TEntity model, IRecursiveEntityUpdater entityUpdater, bool isNew)
{
EntityNavigationPropertyInfo[] collectionProperties = Reflector.GetCollectionNavigationProperties(typeof(TEntity)); // make it work like <TModel>
var collectionUpdater = new ReflectingGenericCollectionPropertyUpdater <TEntity>(new CollectionPropertyUpdater <TEntity>(DbContext, updatedModel, CollectionMerger));
foreach (var property in collectionProperties)
{
collectionUpdater.UpdateCollectionProperty(Reflector, property, model, isNew, entityUpdater);
}
}
protected abstract void UpdateAllNavigationProperties <TEntity>(TEntity updatedModel, TEntity model, IRecursiveEntityUpdater entityUpdater, bool isNew)
where TEntity : class;
protected override void UpdateAllNavigationProperties <TEntity>(TEntity updatedModel, TEntity model, IRecursiveEntityUpdater entityUpdater, bool modelIsNew)
{
EntityNavigationPropertyInfo[] navigationProperties = Reflector.GetDependentNavigationProperties(typeof(TEntity));
var modelUpdater = new ReflectingGenericEntityUpdater <TEntity>();
foreach (var property in navigationProperties)
{
modelUpdater.UpdateProperty(property, model, entityUpdater);
/* TODO: cover scenarios where navigation property has a corresponding foreign key (Id) property.
* Make sure updates work well in those cases because sometimes navigation property might not be loaded (== null)
* but the foreign key property is non-default. In such cases, navigation property of the target model should
* not be set to null. */
}
}
public void UpdateProperty(EntityNavigationPropertyInfo property, TModel newModel, IRecursiveEntityUpdater entityUpdater)
{
GenericMethodInvoker.InvokeGenericMethod(typeof(IRecursiveEntityUpdater), nameof(IRecursiveEntityUpdater.UpdateEntity),
new Type[] { property.PropertyInfo.PropertyType },
GenericMethodInvoker.DefaultPublicInstanceBindingFlags,
new object[] { property.PropertyInfo.GetValue(newModel), entityUpdater },
entityUpdater);
}
