public QueryStringParameterScopeParser(IResourceContextProvider resourceContextProvider, FieldChainRequirements chainRequirements,
Action <ResourceFieldAttribute, ResourceContext, string> validateSingleFieldCallback = null)
: base(resourceContextProvider)
{
_chainRequirements = chainRequirements;
_validateSingleFieldCallback = validateSingleFieldCallback;
}
protected QueryExpression ParseCountOrField(FieldChainRequirements chainRequirements)
{
CountExpression count = TryParseCount();
if (count != null)
{
return(count);
}
return(ParseFieldChain(chainRequirements, "Count function or field name expected."));
}
protected ResourceFieldChainExpression ParseFieldChain(FieldChainRequirements chainRequirements, string alternativeErrorMessage)
{
if (TokenStack.TryPop(out Token token) && token.Kind == TokenKind.Text)
{
var chain = OnResolveFieldChain(token.Value, chainRequirements);
if (chain.Any())
{
return(new ResourceFieldChainExpression(chain));
}
}
throw new QueryParseException(alternativeErrorMessage ?? "Field name expected.");
}
protected QueryExpression ParseCountOrConstantOrNullOrField(FieldChainRequirements chainRequirements)
{
CountExpression count = TryParseCount();
if (count != null)
{
return(count);
}
IdentifierExpression constantOrNull = TryParseConstantOrNull();
if (constantOrNull != null)
{
return(constantOrNull);
}
return(ParseFieldChain(chainRequirements, "Count function, value between quotes, null or field name expected."));
}
protected ComparisonExpression ParseComparison(string operatorName)
{
var comparisonOperator = Enum.Parse <ComparisonOperator>(operatorName.Pascalize());
EatText(operatorName);
EatSingleCharacterToken(TokenKind.OpenParen);
// Allow equality comparison of a HasOne relationship with null.
FieldChainRequirements leftChainRequirements = comparisonOperator == ComparisonOperator.Equals
? FieldChainRequirements.EndsInAttribute | FieldChainRequirements.EndsInToOne
: FieldChainRequirements.EndsInAttribute;
QueryExpression leftTerm = ParseCountOrField(leftChainRequirements);
EatSingleCharacterToken(TokenKind.Comma);
QueryExpression rightTerm = ParseCountOrConstantOrNullOrField(FieldChainRequirements.EndsInAttribute);
EatSingleCharacterToken(TokenKind.CloseParen);
if (leftTerm is ResourceFieldChainExpression leftChain)
{
if (leftChainRequirements.HasFlag(FieldChainRequirements.EndsInToOne) && !(rightTerm is NullConstantExpression))
{
// Run another pass over left chain to have it fail when chain ends in relationship.
OnResolveFieldChain(leftChain.ToString(), FieldChainRequirements.EndsInAttribute);
}
PropertyInfo leftProperty = leftChain.Fields.Last().Property;
if (leftProperty.Name == nameof(Identifiable.Id) && rightTerm is LiteralConstantExpression rightConstant)
{
string id = DeObfuscateStringId(leftProperty.ReflectedType, rightConstant.Value);
rightTerm = new LiteralConstantExpression(id);
}
}
return(new ComparisonExpression(comparisonOperator, leftTerm, rightTerm));
}
/// <summary> /// Takes a dotted path and walks the resource graph to produce a chain of fields. /// </summary> protected abstract IReadOnlyCollection <ResourceFieldAttribute> OnResolveFieldChain(string path, FieldChainRequirements chainRequirements);
protected override IReadOnlyCollection <ResourceFieldAttribute> OnResolveFieldChain(string path, FieldChainRequirements chainRequirements)
{
var field = ChainResolver.GetField(path, _resourceContext, path);
_validateSingleFieldCallback?.Invoke(field, _resourceContext, path);
return(new[] { field });
}
protected override IReadOnlyCollection <ResourceFieldAttribute> OnResolveFieldChain(string path, FieldChainRequirements chainRequirements)
{
if (chainRequirements == FieldChainRequirements.EndsInToMany)
{
return(ChainResolver.ResolveToOneChainEndingInToMany(_resourceContextInScope, path, _validateSingleFieldCallback));
}
if (chainRequirements == FieldChainRequirements.EndsInAttribute)
{
return(ChainResolver.ResolveToOneChainEndingInAttribute(_resourceContextInScope, path, _validateSingleFieldCallback));
}
if (chainRequirements.HasFlag(FieldChainRequirements.EndsInAttribute) &&
chainRequirements.HasFlag(FieldChainRequirements.EndsInToOne))
{
return(ChainResolver.ResolveToOneChainEndingInAttributeOrToOne(_resourceContextInScope, path, _validateSingleFieldCallback));
}
throw new InvalidOperationException($"Unexpected combination of chain requirement flags '{chainRequirements}'.");
}
protected override IReadOnlyCollection <ResourceFieldAttribute> OnResolveFieldChain(string path, FieldChainRequirements chainRequirements)
{
return(ChainResolver.ResolveToManyChain(_resourceContextInScope, path, _validateSingleFieldCallback));
}
protected override IReadOnlyCollection <ResourceFieldAttribute> OnResolveFieldChain(string path, FieldChainRequirements chainRequirements)
{
var attribute = ChainResolver.GetAttribute(path, _resourceContextInScope, path);
_validateSingleAttributeCallback?.Invoke(attribute, _resourceContextInScope, path);
return(new[] { attribute });
}
protected override IReadOnlyCollection <ResourceFieldAttribute> OnResolveFieldChain(string path, FieldChainRequirements chainRequirements)
{
if (chainRequirements == FieldChainRequirements.EndsInToMany)
{
// The mismatch here (ends-in-to-many being interpreted as entire-chain-must-be-to-many) is intentional.
return(ChainResolver.ResolveToManyChain(_resourceContextInScope, path, _validateSingleFieldCallback));
}
if (chainRequirements == FieldChainRequirements.IsRelationship)
{
return(ChainResolver.ResolveRelationshipChain(_resourceContextInScope, path, _validateSingleFieldCallback));
}
throw new InvalidOperationException($"Unexpected combination of chain requirement flags '{chainRequirements}'.");
}
protected override IReadOnlyCollection <ResourceFieldAttribute> OnResolveFieldChain(string path, FieldChainRequirements chainRequirements)
{
throw new NotSupportedException();
}
