/// <summary>
/// Retrieves the LINQ expression that backs this ObjectQuery for external consumption.
/// It is important that the work to wrap the expression in an appropriate MergeAs call
/// takes place in this method and NOT in ObjectQueryState.TryGetExpression which allows
/// the unmodified expression (that does not include the MergeOption-preserving MergeAs call)
/// to be retrieved and processed by the ELinq ExpressionConverter.
/// </summary>
/// <returns>
/// The LINQ expression for this ObjectQuery, wrapped in a MergeOption-preserving call
/// to the MergeAs method if the ObjectQuery.MergeOption property has been set.
/// </returns>
internal override Expression GetExpression()
{
// If this ObjectQuery is not backed by a LINQ Expression (it is an ESQL query),
// then create a ConstantExpression that uses this ObjectQuery as its value.
Expression retExpr;
if (!this.QueryState.TryGetExpression(out retExpr))
{
retExpr = Expression.Constant(this);
}
Type objectQueryType = typeof(ObjectQuery <T>);
if (this.QueryState.UserSpecifiedMergeOption.HasValue)
{
MethodInfo mergeAsMethod = objectQueryType.GetMethod("MergeAs", BindingFlags.Instance | BindingFlags.NonPublic);
Debug.Assert(mergeAsMethod != null, "Could not retrieve ObjectQuery<T>.MergeAs method using reflection?");
retExpr = TypeSystem.EnsureType(retExpr, objectQueryType);
retExpr = Expression.Call(retExpr, mergeAsMethod, Expression.Constant(this.QueryState.UserSpecifiedMergeOption.Value));
}
if (null != this.QueryState.Span)
{
MethodInfo includeSpanMethod = objectQueryType.GetMethod("IncludeSpan", BindingFlags.Instance | BindingFlags.NonPublic);
Debug.Assert(includeSpanMethod != null, "Could not retrieve ObjectQuery<T>.IncludeSpan method using reflection?");
retExpr = TypeSystem.EnsureType(retExpr, objectQueryType);
retExpr = Expression.Call(retExpr, includeSpanMethod, Expression.Constant(this.QueryState.Span));
}
return(retExpr);
}
// <summary>
// Retrieves the LINQ expression that backs this ObjectQuery for external consumption.
// It is important that the work to wrap the expression in an appropriate MergeAs call
// takes place in this method and NOT in ObjectQueryState.TryGetExpression which allows
// the unmodified expression (that does not include the MergeOption-preserving MergeAs call)
// to be retrieved and processed by the ELinq ExpressionConverter.
// </summary>
// <returns> The LINQ expression for this ObjectQuery, wrapped in a MergeOption-preserving call to the MergeAs method if the ObjectQuery.MergeOption property has been set. </returns>
internal override Expression GetExpression()
{
// If this ObjectQuery is not backed by a LINQ Expression (it is an ESQL query),
// then create a ConstantExpression that uses this ObjectQuery as its value.
Expression retExpr;
if (!QueryState.TryGetExpression(out retExpr))
{
retExpr = Expression.Constant(this);
}
if (QueryState.UserSpecifiedMergeOption.HasValue)
{
retExpr = TypeSystem.EnsureType(retExpr, typeof(ObjectQuery <T>));
retExpr = Expression.Call(retExpr, MergeAsMethod, Expression.Constant(QueryState.UserSpecifiedMergeOption.Value));
}
if (null != QueryState.Span)
{
retExpr = TypeSystem.EnsureType(retExpr, typeof(ObjectQuery <T>));
retExpr = Expression.Call(retExpr, IncludeSpanMethod, Expression.Constant(QueryState.Span));
}
return(retExpr);
}
internal override Expression GetExpression()
{
Expression expression;
if (!this.QueryState.TryGetExpression(out expression))
{
expression = (Expression)Expression.Constant((object)this);
}
if (this.QueryState.UserSpecifiedMergeOption.HasValue)
{
expression = (Expression)Expression.Call(TypeSystem.EnsureType(expression, typeof(ObjectQuery <T>)), ObjectQuery <T> .MergeAsMethod, (Expression)Expression.Constant((object)this.QueryState.UserSpecifiedMergeOption.Value));
}
if (this.QueryState.Span != null)
{
expression = (Expression)Expression.Call(TypeSystem.EnsureType(expression, typeof(ObjectQuery <T>)), ObjectQuery <T> .IncludeSpanMethod, (Expression)Expression.Constant((object)this.QueryState.Span));
}
return(expression);
}