protected DataServiceQueryable(IEntitySet <TBase> entitySet, DataServiceQueryable parent)
: base(parent)
{
this.EntitySet = entitySet;
Initialize();
}
internal DataServiceQueryableImp(DataServiceQueryable <TEntity, TBase> source, IEnumerable <TBase> enumerable)
: base(source.EntitySet, source)
{
this._enumerable = enumerable;
}
protected DataServiceQueryable(DataServiceQueryable parent)
{
this.Parent = parent;
Initialize();
}
private void LoadData(IEntityCollectionView <T> view)
{
#region query
var requestId = ++RequestId;
var query = Queryable.IncludeTotalCount();
#endregion query
#region paging
if (view.PageSize > 0)
{
query = query
.Skip(view.PageIndex * view.PageSize)
.Take(view.PageSize);
}
#endregion pagging
#region filters
foreach (var filterExpression in view.FilterExpressions)
{
var remoteExpression = DataServiceQueryable.ToRemoteExpression(filterExpression);
query = query.Where(remoteExpression);
}
#endregion filters
#region sorting
// apply sort descriptors
IOrderedDataServiceQueryable <T, T> sortedQuery = null;
foreach (var sortDescription in view.SortDescriptions)
{
var sortExpression = sortDescription.ToExpression <T>();
if (ReferenceEquals(sortedQuery, null))
{
sortedQuery = query.OrderBy(sortExpression);
}
else
{
sortedQuery = sortedQuery.ThenBy(sortExpression);
}
}
if (!ReferenceEquals(sortedQuery, null))
{
query = sortedQuery;
}
#endregion sorting
#region request
// notify data loading
OnDataLoading();
query.ExecuteAsync(
(result) =>
{
if (requestId < RequestId)
{
// request outdated
return;
}
// synchronize with main thread
Dispatcher.BeginInvoke((Action) delegate
{
// check for exception
if (result.IsFaulted)
{
var queryException = QueryException;
if (queryException != null)
{
queryException(this, new ExceptionEventArgs(result.Exception));
OnDataLoaded(null);
return;
}
else
{
throw new Exception("Query failed", result.Exception);
}
}
// retrieve data
var entitySet = result.EntitySet;
// fill items
view.Clear();
foreach (var item in entitySet)
{
view.Add(item);
}
// sets total count
view.TotalItemCount = entitySet.TotalCount.HasValue ? (int)entitySet.TotalCount.Value : -1;
// notify data loaded
OnDataLoaded(entitySet);
});
}
);
#endregion request
}
internal DataServiceQueryableImp(IEntitySet <TBase> source, DataServiceQueryable parent)
: base(source, parent)
{
}
internal DataServiceQueryableImp(DataServiceQueryable <TEntity, TBase> source)
: base(source.EntitySet, source)
{
}
private bool ParseExpression(MethodCallExpression expression)
{
switch (expression.Method.Name)
{
case "Where":
{
var exp = (Expression <Func <TEntity, bool> >)((UnaryExpression)expression.Arguments[1]).Operand;
_queriable = (DataServiceQueryable <TEntity, TBase>)_queriable.Where(exp);
}
break;
case "First":
{
if (expression.Arguments.Count > 1)
{
var exp = (Expression <Func <TEntity, bool> >)((UnaryExpression)expression.Arguments[1]).Operand;
_queriable = new DataServiceQueryableImp <TEntity, TBase>(_queriable, new[] { _queriable.First(exp) });
}
else
{
_queriable = new DataServiceQueryableImp <TEntity, TBase>(_queriable, new[] { _queriable.First() });
}
}
break;
case "FirstOrDefault":
{
if (expression.Arguments.Count > 1)
{
var exp = (Expression <Func <TEntity, bool> >)((UnaryExpression)expression.Arguments[1]).Operand;
_queriable = new DataServiceQueryableImp <TEntity, TBase>(_queriable, new[] { _queriable.FirstOrDefault(exp) });
}
else
{
_queriable = new DataServiceQueryableImp <TEntity, TBase>(_queriable, new[] { _queriable.FirstOrDefault() });
}
}
break;
case "Single":
{
if (expression.Arguments.Count > 1)
{
var exp = (Expression <Func <TEntity, bool> >)((UnaryExpression)expression.Arguments[1]).Operand;
_queriable = new DataServiceQueryableImp <TEntity, TBase>(_queriable, new[] { _queriable.Single(exp) });
}
else
{
_queriable = new DataServiceQueryableImp <TEntity, TBase>(_queriable, new[] { _queriable.Single() });
}
}
break;
case "SingleOrDefault":
{
if (expression.Arguments.Count > 1)
{
var exp = (Expression <Func <TEntity, bool> >)((UnaryExpression)expression.Arguments[1]).Operand;
_queriable = new DataServiceQueryableImp <TEntity, TBase>(_queriable, new[] { _queriable.SingleOrDefault(exp) });
}
else
{
_queriable = new DataServiceQueryableImp <TEntity, TBase>(_queriable, new[] { _queriable.SingleOrDefault() });
}
}
break;
case "OrderBy":
{
var exp = (UnaryExpression)expression.Arguments[1];
_queriable = (DataServiceQueryable <TEntity, TBase>)_queriable.OrderBy((LambdaExpression)exp.Operand);
}
break;
case "OrderByDescending":
{
var exp = (UnaryExpression)expression.Arguments[1];
_queriable = (DataServiceQueryable <TEntity, TBase>)_queriable.OrderByDescending((LambdaExpression)exp.Operand);
}
break;
case "ThenBy":
{
var exp = (UnaryExpression)expression.Arguments[1];
_queriable = (DataServiceQueryable <TEntity, TBase>)((OrderedDataServiceQueryable <TEntity, TBase>)_queriable).ThenBy((LambdaExpression)exp.Operand);
}
break;
case "ThenByDescending":
{
var exp = (UnaryExpression)expression.Arguments[1];
_queriable = (DataServiceQueryable <TEntity, TBase>)((OrderedDataServiceQueryable <TEntity, TBase>)_queriable).ThenByDescending((LambdaExpression)exp.Operand);
}
break;
case "Skip":
{
var exp = (ConstantExpression)expression.Arguments[1];
_queriable = (DataServiceQueryable <TEntity, TBase>)_queriable.Skip((int)exp.Value);
}
break;
case "Take":
{
var exp = (ConstantExpression)expression.Arguments[1];
_queriable = (DataServiceQueryable <TEntity, TBase>)_queriable.Take((int)exp.Value);
}
break;
case "Count":
{
if (expression.Arguments.Count == 2)
{
var exp = (Expression <Func <TEntity, bool> >)((UnaryExpression)expression.Arguments[1]).Operand;
_totalCountInt32 = _queriable.Count(exp);
}
else
{
_totalCountInt32 = _queriable.Count();
}
}
break;
case "LongCount":
{
if (expression.Arguments.Count == 2)
{
var exp = (Expression <Func <TEntity, bool> >)((UnaryExpression)expression.Arguments[1]).Operand;
_totalCountInt64 = _queriable.LongCount(exp);
}
else
{
_totalCountInt64 = _queriable.LongCount();
}
}
break;
default:
return(false);
}
return(true);
}
internal QueryProvider(DataServiceQueryable <TEntity, TBase> queriable)
{
_queriable = queriable;
}
internal OrderedDataServiceQueryable(DataServiceQueryable <TEntity, TBase> queryable)
: base(queryable.EntitySet, queryable)
{
_queryable = queryable;
}
