public static Expression <Func <ExportDefinition, bool> > CreateConstraint(string contractName, string requiredTypeIdentity, IEnumerable <KeyValuePair <string, Type> > requiredMetadata, CreationPolicy requiredCreationPolicy)
{
ParameterExpression parameter = Expression.Parameter(typeof(ExportDefinition), "exportDefinition");
Expression constraintBody = ConstraintServices.CreateContractConstraintBody(contractName, parameter);
if (!string.IsNullOrEmpty(requiredTypeIdentity))
{
Expression typeIdentityConstraintBody = ConstraintServices.CreateTypeIdentityContraint(requiredTypeIdentity, parameter);
constraintBody = Expression.AndAlso(constraintBody, typeIdentityConstraintBody);
}
if (requiredMetadata != null)
{
Expression metadataConstraintBody = ConstraintServices.CreateMetadataConstraintBody(requiredMetadata, parameter);
if (metadataConstraintBody != null)
{
constraintBody = Expression.AndAlso(constraintBody, metadataConstraintBody);
}
}
if (requiredCreationPolicy != CreationPolicy.Any)
{
Expression policyConstraintBody = ConstraintServices.CreateCreationPolicyContraint(requiredCreationPolicy, parameter);
constraintBody = Expression.AndAlso(constraintBody, policyConstraintBody);
}
Expression <Func <ExportDefinition, bool> > constraint = Expression.Lambda <Func <ExportDefinition, bool> >(constraintBody, parameter);
return(constraint);
}
public static Expression <Func <ExportDefinition, bool> > CreateConstraint(IEnumerable <KeyValuePair <string, Type> > requiredMetadata)
{
ParameterExpression parameter = Expression.Parameter(typeof(ExportDefinition), "exportDefinition");
Expression metadataConstraintBody = null;
if (requiredMetadata != null)
{
metadataConstraintBody = ConstraintServices.CreateMetadataConstraintBody(requiredMetadata, parameter);
}
if (metadataConstraintBody != null)
{
return(Expression.Lambda <Func <ExportDefinition, bool> >(metadataConstraintBody, parameter));
}
return(null);
}
