public override JsExpression GetJsTranslation(JsExpression dataContext)
{
return(dataContext.Member("$control").WithAnnotation(new ViewModelInfoAnnotation(ResolvedTypeDescriptor.ToSystemType(this.ParameterType), isControl: true)));
}
public override Expression GetServerEquivalent(Expression controlParameter)
{
return(Expression.Convert(ExpressionUtils.Replace((DotvvmBindableObject c) => c.GetClosestControlBindingTarget(), controlParameter), ResolvedTypeDescriptor.ToSystemType(ParameterType)));
}
/// This is a strange conversion that wraps the entire expression into a Lambda
/// and makes an invokable delegate from a normal expression.
/// It also replaces special ExtensionParameters attached to the expression for lambda parameters
public static Expression MagicLambdaConversion(Expression expr, Type expectedType)
{
if (expectedType.IsDelegate())
{
var resultType = expectedType.GetMethod("Invoke").ReturnType;
var delegateArgs = expectedType
.GetMethod("Invoke")
.GetParameters()
.Select(p => Expression.Parameter(p.ParameterType, p.Name))
.ToArray();
var convertedToResult = TypeConversion.ImplicitConversion(expr, resultType) ?? TaskConversion(expr, resultType);
// TODO: convert delegates to another delegates
if (convertedToResult == null)
{
return(null);
}
else
{
var replacedArgs = convertedToResult.ReplaceAll(arg =>
arg?.GetParameterAnnotation()?.ExtensionParameter is MagicLambdaConversionExtensionParameter extensionParam ?
delegateArgs.Single(a => a.Name == extensionParam.Identifier)
.Assert(p => p.Type == ResolvedTypeDescriptor.ToSystemType(extensionParam.ParameterType)) :
arg
);
return(Expression.Lambda(
expectedType,
replacedArgs,
delegateArgs
));
}
}
else
{
return(null);
}
}
protected override IControlType CreateControlType(ITypeDescriptor wrapperType, string virtualPath)
{
return(new ControlType(ResolvedTypeDescriptor.ToSystemType(wrapperType), virtualPath: virtualPath));
}
static ParameterExpression CreateParameter(DataContextStack stackItem, string name, BindingExtensionParameter extensionParameter = null) => Expression.Parameter((extensionParameter == null ? stackItem.DataContextType : ResolvedTypeDescriptor.ToSystemType(extensionParameter.ParameterType)) ?? typeof(ExpressionHelper.UnknownTypeSentinel), name) .AddParameterAnnotation(new BindingParameterAnnotation(stackItem, extensionParameter));
