/// <summary>
/// A function to construct projection context and populate the resolved attribute set that ExtractResolvedAttributes method can then extract
/// This function is the entry point for projection resolution.
/// This function is expected to do the following 3 things:
/// - Create an condition expression tree & default if appropriate
/// - Create and initialize Projection Context
/// - Process operations
/// </summary>
/// <param name="projDirective"></param>
/// <param name="attrCtx"></param>
/// <returns></returns>
internal ProjectionContext ConstructProjectionContext(ProjectionDirective projDirective, CdmAttributeContext attrCtx)
{
ProjectionContext projContext = null;
if (string.IsNullOrWhiteSpace(this.Condition))
{
// if no condition is provided, get default condition and persist
this.Condition = ConditionExpression.GetDefaultConditionExpression(this.Operations, this.Owner);
}
// create an expression tree based on the condition
ExpressionTree tree = new ExpressionTree();
this.ConditionExpressionTreeRoot = tree.ConstructExpressionTree(this.Condition);
if (this.ConditionExpressionTreeRoot == null)
{
Logger.Info(nameof(CdmProjection), this.Ctx, $"Optional expression missing. Implicit expression will automatically apply.", nameof(ConstructProjectionContext));
}
if (attrCtx != null)
{
// Add projection to context tree
AttributeContextParameters acpProj = new AttributeContextParameters
{
under = attrCtx,
type = CdmAttributeContextType.Projection,
Name = this.FetchObjectDefinitionName(),
Regarding = projDirective.OwnerRef,
IncludeTraits = false
};
CdmAttributeContext acProj = CdmAttributeContext.CreateChildUnder(projDirective.ResOpt, acpProj);
AttributeContextParameters acpSource = new AttributeContextParameters
{
under = acProj,
type = CdmAttributeContextType.Source,
Name = "source",
Regarding = null,
IncludeTraits = false
};
CdmAttributeContext acSource = CdmAttributeContext.CreateChildUnder(projDirective.ResOpt, acpSource);
if (this.Source.FetchObjectDefinition <CdmObjectDefinition>(projDirective.ResOpt).ObjectType == CdmObjectType.ProjectionDef)
{
// A Projection
projContext = ((CdmProjection)this.Source.ExplicitReference).ConstructProjectionContext(projDirective, acSource);
}
else
{
// An Entity Reference
AttributeContextParameters acpSourceProjection = new AttributeContextParameters
{
under = acSource,
type = CdmAttributeContextType.Entity,
Name = this.Source.NamedReference ?? this.Source.ExplicitReference.GetName(),
Regarding = this.Source,
IncludeTraits = false
};
ResolvedAttributeSet ras = this.Source.FetchResolvedAttributes(projDirective.ResOpt, acpSourceProjection);
// Initialize the projection context
CdmCorpusContext ctx = (projDirective.Owner?.Ctx);
ProjectionAttributeStateSet pasSet = null;
// if polymorphic keep original source as previous state
Dictionary <string, List <ProjectionAttributeState> > polySourceSet = null;
if (projDirective.IsSourcePolymorphic)
{
polySourceSet = ProjectionResolutionCommonUtil.GetPolymorphicSourceSet(projDirective, ctx, this.Source, acpSourceProjection);
}
// now initialize projection attribute state
pasSet = ProjectionResolutionCommonUtil.InitializeProjectionAttributeStateSet(
projDirective,
ctx,
ras,
isSourcePolymorphic: projDirective.IsSourcePolymorphic,
polymorphicSet: polySourceSet);
projContext = new ProjectionContext(projDirective, ras.AttributeContext)
{
CurrentAttributeStateSet = pasSet
};
}
bool isConditionValid = false;
if (this.ConditionExpressionTreeRoot != null)
{
InputValues input = new InputValues()
{
noMaxDepth = projDirective.HasNoMaximumDepth,
isArray = projDirective.IsArray,
referenceOnly = projDirective.IsReferenceOnly,
normalized = projDirective.IsNormalized,
structured = projDirective.IsStructured,
nextDepth = ++projDirective.CurrentDepth,
maxDepth = projDirective.MaximumDepth,
minCardinality = projDirective.Cardinality?._MinimumNumber,
maxCardinality = projDirective.Cardinality?._MaximumNumber
};
isConditionValid = ExpressionTree.EvaluateExpressionTree(this.ConditionExpressionTreeRoot, input);
}
if (isConditionValid && this.Operations != null && this.Operations.Count > 0)
{
// Just in case new operations were added programmatically, reindex operations
for (int i = 0; i < this.Operations.Count; i++)
{
this.Operations[i].Index = i + 1;
}
// Operation
AttributeContextParameters acpGenAttrSet = new AttributeContextParameters
{
under = attrCtx,
type = CdmAttributeContextType.GeneratedSet,
Name = "_generatedAttributeSet"
};
CdmAttributeContext acGenAttrSet = CdmAttributeContext.CreateChildUnder(projDirective.ResOpt, acpGenAttrSet);
AttributeContextParameters acpGenAttrRound0 = new AttributeContextParameters
{
under = acGenAttrSet,
type = CdmAttributeContextType.GeneratedRound,
Name = "_generatedAttributeRound0"
};
CdmAttributeContext acGenAttrRound0 = CdmAttributeContext.CreateChildUnder(projDirective.ResOpt, acpGenAttrRound0);
// Start with an empty list for each projection
ProjectionAttributeStateSet pasOperations = new ProjectionAttributeStateSet(projContext.CurrentAttributeStateSet.Ctx);
foreach (CdmOperationBase operation in this.Operations)
{
// Evaluate projections and apply to empty state
ProjectionAttributeStateSet newPasOperations = operation.AppendProjectionAttributeState(projContext, pasOperations, acGenAttrRound0);
// If the operations fails or it is not implemented the projection cannot be evaluated so keep previous valid state.
if (newPasOperations != null)
{
pasOperations = newPasOperations;
}
}
// Finally update the current state to the projection context
projContext.CurrentAttributeStateSet = pasOperations;
}
else
{
// Pass Through - no operations to process
}
}
return(projContext);
}
public void TestGetDefaultConditionExpression()
{
CdmCorpusDefinition corpus = TestHelper.GetLocalCorpus(testsSubpath, "TestGetDefaultConditionExpression");
corpus.Storage.Mount("local", new LocalAdapter(TestHelper.GetActualOutputFolderPath(testsSubpath, "TestGetDefaultConditionExpression")));
CdmFolderDefinition localRoot = corpus.Storage.FetchRootFolder("local");
CdmManifestDefinition manifestDefault = CreateDefaultManifest(corpus, localRoot);
CdmEntityDefinition entityTestSource = CreateEntityTestSource(corpus, manifestDefault, localRoot);
// projection for a non entity attribute
CdmOperationCollection opColl = new CdmOperationCollection(corpus.Ctx, entityTestSource);
{
// add 1st FK
opColl.Add(new CdmOperationReplaceAsForeignKey(corpus.Ctx));
Assert.AreEqual($" (referenceOnly || noMaxDepth || (depth > maxDepth)) ", ConditionExpression.GetDefaultConditionExpression(opColl, owner: entityTestSource));
// add 2nd FK
opColl.Add(new CdmOperationReplaceAsForeignKey(corpus.Ctx));
Assert.AreEqual($" (referenceOnly || noMaxDepth || (depth > maxDepth)) ", ConditionExpression.GetDefaultConditionExpression(opColl, owner: entityTestSource));
opColl.Clear();
// add AddCount
opColl.Add(new CdmOperationAddCountAttribute(corpus.Ctx));
Assert.AreEqual($" (!structured) ", ConditionExpression.GetDefaultConditionExpression(opColl, owner: entityTestSource));
// add ArrayExpansion
opColl.Add(new CdmOperationArrayExpansion(corpus.Ctx));
Assert.AreEqual($" (!structured) ", ConditionExpression.GetDefaultConditionExpression(opColl, owner: entityTestSource));
opColl.Clear();
// add AddSupporting
opColl.Add(new CdmOperationAddSupportingAttribute(corpus.Ctx));
Assert.AreEqual($" (true) ", ConditionExpression.GetDefaultConditionExpression(opColl, owner: entityTestSource));
}
CdmEntityAttributeDefinition entityTestEntityAttribute = corpus.MakeObject <CdmEntityAttributeDefinition>(CdmObjectType.EntityAttributeDef, nameOrRef: "TestEntityAttribute", simpleNameRef: false);
// projection for a non entity attribute
CdmOperationCollection opCollEA = new CdmOperationCollection(corpus.Ctx, entityTestEntityAttribute);
{
// add 1st FK
opCollEA.Add(new CdmOperationReplaceAsForeignKey(corpus.Ctx));
Assert.AreEqual($" ( (!normalized) || (cardinality.maximum <= 1) ) && (referenceOnly || noMaxDepth || (depth > maxDepth)) ", ConditionExpression.GetDefaultConditionExpression(opCollEA, owner: entityTestEntityAttribute));
// add 2nd FK
opCollEA.Add(new CdmOperationReplaceAsForeignKey(corpus.Ctx));
Assert.AreEqual($" ( (!normalized) || (cardinality.maximum <= 1) ) && (referenceOnly || noMaxDepth || (depth > maxDepth)) ", ConditionExpression.GetDefaultConditionExpression(opCollEA, owner: entityTestEntityAttribute));
opCollEA.Clear();
// add AddCount
opCollEA.Add(new CdmOperationAddCountAttribute(corpus.Ctx));
Assert.AreEqual($" ( (!normalized) || (cardinality.maximum <= 1) ) && (!structured) ", ConditionExpression.GetDefaultConditionExpression(opCollEA, owner: entityTestEntityAttribute));
// add ArrayExpansion
opCollEA.Add(new CdmOperationArrayExpansion(corpus.Ctx));
Assert.AreEqual($" ( (!normalized) || (cardinality.maximum <= 1) ) && (!structured) ", ConditionExpression.GetDefaultConditionExpression(opCollEA, owner: entityTestEntityAttribute));
opCollEA.Clear();
// add AddSupporting
opCollEA.Add(new CdmOperationAddSupportingAttribute(corpus.Ctx));
Assert.AreEqual($" ( (!normalized) || (cardinality.maximum <= 1) ) && (true) ", ConditionExpression.GetDefaultConditionExpression(opCollEA, owner: entityTestEntityAttribute));
}
}
