private bool TryGetDsInfo(CallNode callNode, TexlBinding binding, out IExternalDataSource dsInfo)
{
Contracts.AssertValueOrNull(callNode);
Contracts.AssertValue(binding);
dsInfo = null;
if (callNode == null || !binding.IsDelegatable(callNode) || !binding.GetType(callNode).IsTable)
{
return(false);
}
var callInfo = binding.GetInfo(callNode);
if (callInfo == null)
{
return(false);
}
var function = callInfo.Function;
if (function == null)
{
return(false);
}
bool success = function.TryGetDataSource(callNode, binding, out var external);
dsInfo = (IExternalDataSource)external;
return(success);
}
// Verifies if given callnode can be server delegatable or not.
// Return true if
// - Arg0 is delegatable ds and supports filter operation.
// - All predicates to filter are delegatable if each firstname/binary/unary/dottedname/call node in each predicate satisfies delegation criteria set by delegation strategy for each node.
public override bool IsServerDelegatable(CallNode callNode, TexlBinding binding)
{
Contracts.AssertValue(callNode);
Contracts.AssertValue(binding);
if (!CheckArgsCount(callNode, binding))
{
return(false);
}
IExternalDataSource dataSource;
FilterOpMetadata metadata = null;
IDelegationMetadata delegationMetadata = null;
if (TryGetEntityMetadata(callNode, binding, out delegationMetadata))
{
if (!binding.Document.Properties.EnabledFeatures.IsEnhancedDelegationEnabled ||
!TryGetValidDataSourceForDelegation(callNode, binding, DelegationCapability.ArrayLookup, out _))
{
SuggestDelegationHint(callNode, binding);
return(false);
}
metadata = delegationMetadata.FilterDelegationMetadata.VerifyValue();
}
else
{
if (!TryGetValidDataSourceForDelegation(callNode, binding, FunctionDelegationCapability, out dataSource))
{
return(false);
}
metadata = dataSource.DelegationMetadata.FilterDelegationMetadata;
}
TexlNode[] args = callNode.Args.Children.VerifyValue();
if (args.Length > 2 && binding.IsDelegatable(args[2]))
{
SuggestDelegationHint(args[2], binding);
return(false);
}
if (args.Length < 2)
{
return(false);
}
return(IsValidDelegatableFilterPredicateNode(args[1], binding, metadata));
}