public ParsedExpressionBindingProperty GetExpression(OriginalStringBindingProperty originalString, DataContextStack dataContext, BindingParserOptions options, ExpectedTypeBindingProperty expectedType = null)
{
var expr = bindingParser.ParseWithLambdaConversion(originalString.Code, dataContext, options, expectedType?.Type ?? typeof(object));
if (expr is StaticClassIdentifierExpression)
{
throw new Exception($"'{originalString.Code}' is a static class reference, not a valid expression.");
}
else if (expr is UnknownStaticClassIdentifierExpression)
{
expr = expr.Reduce();
}
return(new ParsedExpressionBindingProperty(expr));
}
public CastedExpressionBindingProperty ConvertExpressionToType(ParsedExpressionBindingProperty expr, ExpectedTypeBindingProperty expectedType = null)
{
var destType = expectedType?.Type ?? typeof(object);
var convertedExpr = TypeConversion.ImplicitConversion(expr.Expression, destType, throwException: false, allowToString: true);
return(new CastedExpressionBindingProperty(
// if the expression is of type object (i.e. null literal) try the lambda conversion.
convertedExpr != null && expr.Expression.Type != typeof(object) ? convertedExpr :
TypeConversion.MagicLambdaConversion(expr.Expression, destType) ??
TypeConversion.ImplicitConversion(expr.Expression, destType, throwException: true, allowToString: true)
));
}
public CastedExpressionBindingProperty ConvertExpressionToType(ParsedExpressionBindingProperty expr, ExpectedTypeBindingProperty expectedType = null) => new CastedExpressionBindingProperty(TypeConversion.ImplicitConversion(expr.Expression, expectedType?.Type ?? typeof(object), throwException: true, allowToString: true));
public CommandJavascriptBindingProperty CreateJs(IdBindingProperty id, ExpectedTypeBindingProperty expectedType = null) =>
new CommandJavascriptBindingProperty(CreateJsPostbackInvocation(
id.Id,
needsCommandArgs: expectedType?.Type?.GetDelegateArguments()?.Length.Apply(len => len != 0)
));
public CastedExpressionBindingProperty ConvertExpressionToType(ParsedExpressionBindingProperty exprP, ExpectedTypeBindingProperty expectedTypeP = null)
{
var expr = exprP.Expression;
var expectedType = expectedTypeP?.Type ?? typeof(object);
if (expectedType == typeof(object))
{
expectedType = typeof(Command);
}
if (!typeof(Delegate).IsAssignableFrom(expectedType))
{
throw new Exception($"Command bindings must be assigned to properties of Delegate type, not { expectedType }");
}
var normalConvert = TypeConversion.ImplicitConversion(expr, expectedType);
if (normalConvert != null && expr.Type != typeof(object))
{
return(new CastedExpressionBindingProperty(normalConvert));
}
// wrap expression into a lambda
if (typeof(Delegate).IsAssignableFrom(expectedType) && !typeof(Delegate).IsAssignableFrom(expr.Type))
{
var invokeMethod = expectedType.GetMethod("Invoke");
expr = TaskConversion(expr, invokeMethod.ReturnType);
return(new CastedExpressionBindingProperty(Expression.Lambda(
expectedType,
expr,
invokeMethod.GetParameters().Select(p => Expression.Parameter(p.ParameterType, p.Name))
)));
}
// TODO: convert delegates to another delegates
throw new Exception($"Can not convert expression '{ expr }' to '{expectedType}'.");
}
