private IFilterNode ParseComparisonExpression(IFilterNode firstArgument)
{
if (Is(FilterTokenType.ComparisonOperator))
{
FilterToken comparison = Expect(FilterTokenType.ComparisonOperator);
IFilterNode secondArgument = PrimaryExpression();
return(new ComparisonNode
{
First = firstArgument,
FilterOperator = comparison.ToFilterOperator(),
Second = secondArgument
});
}
else if (IsIn(FilterTokenType.Function))
{
return(ParseFunctionExpression(firstArgument));
}
FilterToken function = Expect(FilterTokenType.Function);
var functionNode = new FunctionNode
{
FilterOperator = function.ToFilterOperator()
};
functionNode.Arguments.Add(firstArgument);
functionNode.Arguments.Add(PrimaryExpression());
return(functionNode);
}
private IFilterNode ParsePropertyExpression()
{
FilterToken property = Expect(FilterTokenType.Property);
return(new PropertyNode
{
Name = property.Value
});
}
private IFilterNode ParseNull()
{
FilterToken stringToken = Expect(FilterTokenType.Null);
return(new NullNode
{
Value = null
});
}
private IFilterNode ParseBoolean()
{
FilterToken stringToken = Expect(FilterTokenType.Boolean);
return(new BooleanNode
{
Value = Convert.ToBoolean(stringToken.Value)
});
}
private IFilterNode ParseStringExpression()
{
FilterToken stringToken = Expect(FilterTokenType.String);
return(new StringNode
{
Value = stringToken.Value
});
}
private IFilterNode ParseNumberExpression()
{
FilterToken number = Expect(FilterTokenType.Number);
return(new NumberNode
{
// Always expect the decimal separator to be "." no matter what the current culture is
Value = Convert.ToDouble(number.Value, CultureInfo.InvariantCulture)
});
}
private IFilterNode ParseDateTimeExpression()
{
FilterToken dateTime = Expect(FilterTokenType.DateTime);
return(new DateTimeNode
{
//The actual XSD date format is yyyy-MM-ddTHH:mm:ss but ":" generates BAD REQUEST HTTP code when send via GET.
//That's why we are using yyyy-MM-ddThh-mm-ss
Value = DateTime.ParseExact(dateTime.Value, "yyyy-MM-ddTHH-mm-ss", null)
});
}
private FilterToken Expect(FilterTokenType tokenType)
{
if (!Is(tokenType))
{
throw new FilterParserException("Expected " + tokenType);
}
FilterToken token = Peek();
currentTokenIndex++;
return(token);
}
private IFilterNode ParseFunctionExpression()
{
FilterToken function = Expect(FilterTokenType.Function);
var functionNode = new FunctionNode
{
FilterOperator = function.ToFilterOperator()
};
Expect(FilterTokenType.LeftParenthesis);
functionNode.Arguments.Add(Expression());
while (Is(FilterTokenType.Comma))
{
Expect(FilterTokenType.Comma);
functionNode.Arguments.Add(Expression());
}
Expect(FilterTokenType.RightParenthesis);
return(functionNode);
}
private bool IsIn(FilterTokenType tokenType)
{
FilterToken token = Peek();
return(token != null && token.TokenType == tokenType && token.Value.Equals("in", StringComparison.CurrentCultureIgnoreCase));
}
private bool Is(FilterTokenType tokenType)
{
FilterToken token = Peek();
return(token != null && token.TokenType == tokenType);
}
public static FilterOperator ToFilterOperator(this FilterToken token)
{
return(tokenToOperator[token.Value]);
}