I am using rio binding. Now I want to use the MVXConverter, but I do not know how to bind a property with a ValueConverter... The mvx.bi.nd let me bind a property, but never saw an example with using a converter. Does anyone know how to do it?
Related
Looking for a way to do something like the following:
NewtonSoft.Json.JsonConvert.Populate<IMyContract>(jsonStr, currentObj);
where the json.net engine would only attempt to populate the properties that are identified in the IMyContract.
Any suggestions?
Maybe u can use
PopulateObject(String, Object, JsonSerializerSettings)
And use your own JsonSerializerSettings. See: http://james.newtonking.com/projects/json/help/html/T_Newtonsoft_Json_JsonSerializerSettings.htm
Try to use one of the delegates to restrict the properties that are set yourself. That can be based on an Interface, using reflection.
I don't know any other way. If you don't get it with the JsonSerializerSettings you can always write your own PopulateObject method using the Json framework.
If any control (e.g. a DataGrid) is cast to UIComponent, how can you get its type at runtime?
Is this possible in Actionscript?
You can use getQualifiedClassName() to get class name by the value as a string. You can use describeType() to get the full information about class. And you can use constructor property to get class itself (to instantiate new instance by existing instance). Finally you can use is operator to compare to the limited set of classes. Less recommended usage of typeof operator which is rather obsolete.
To select the right way we need to know your particular problem.
I'm trying to use Webservice component in my Flex 4 application.
I need to use this in Actioncript and not using MXML tags.
I'm able to invoke the WSDL operations successfully, but the resultFormat is Object by default.
How do I set it to e4x?
var lookupService:WebService = new WebService();
lookupService.wsdl =url;
lookupService.loadWSDL();
lookupService.doLookup.addEventListener(ResultEvent.RESULT, lookupResultHandler);
lookupService.doLookup.addEventListener(FaultEvent.FAULT, faultHandler);
lookupService.doLookup(lookupString);
I tried to set the format by
lookupService.resultFormat = "e4x";
But this is not working. The calls are not even going through when I do this.
Can you please provide your suggestions for implementing this using AS3?
If you take a look at the two web service classes, you'll realize that resultFormat is not a property on either of them. Resultset is a property on the operations array.
If that doesn't help, you'll have to quantify "not working." What isn't working? Are you getting compile errors? Are you getting runtime errors? IS the data not being returned? Is the data not be returned as XML?
You'll probably have to set this up in MXML and dissect the generated ActionScript to figure out the appropriate AS3 syntax.
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/mx/rpc/soap/WebService.html
Using SilverLight, one can bind the value of a control to a property from a datacontext. That's fine.
It is possible to use StringFormat along with the binding declaration to format the value. Again, that's cool!
However, I can't find a way to have the binding with some operation done to it before it gets displayed. I know I can code an IConverter but I was looking for something purely in XAML if that exists. I could also add a property to the class that returns the data in the correct way, but still what would happen if you don't have the source of the class?
For example, let's say I have this class for my datacontext (properly setup with notification and the like):
public class Info
{
public int SomeValue {...} // Value from 0 to 15
}
I would like to have a binding that would display 45 instead of 15 where the binding would be declared something like {Binding SomeValue, Operation="*3"}
Is there something like this in the .NET world (either from MSoft or OpenSource)?
found the link I was talking about.
Still, Charles Petzold also suggest to rather use a ValueConverter, even though some arithmetics is possible in pure XAML
I use a lot of repeaters for different elements of our sites, and I've always wondered if there was a way to have the repeater skip an element if an exception occurs instead of having the whole page crash?
In particular, I've inherited a system from another developer that using a similar design, however he didn't include any kind of validation for his business objects, and it a single property is missing, the whole thing goes up in smoke.
Any suggestions?
Thanks in advance!
The simplest suggestion I can offer is the check the validity of the data before it's passed to the repeater. I don't believe there's any way to get the stock repeater to skip a data element on error.
The other approach is to build your own repeater, inheriting from the base Repeater, to add that functionality but I've no sample code to offer. Perhaps someone else may be able to help there.
The way I see it, you have at least three options.
You could create a custom repeater control that inherits System.Web.UI.WebControls.Repeater and override the databinding behaviour to be more try-catchy (probably fail silently on databinding errors). You couldd then easily replace all instances of the standard Repeater with this new one.
You could filter your datasources before databinding to remove items you know are going to cause problems beforehand. This option may be quite laborious and something of an iterative process.
You could try adding default values to the business objects, so that the properties you're binding to return a default instance rather than null (not nice either).
That's my thoughts anyway.
One question - you say "when a property is missing". Do you mean he's using a style of databinding syntax that offers no compile-time checking and is referencing properties that don't exist, or is referecing properties that are null?
Edit
OK, so you're referencing properties that are null. If you have access to the code for the business objects you could modify them so they return a new, non-null instance (this is the third option I gave).
You don't say if you're using .net 3.5, but I'll assume you are. You could add a new property "IsValidForDataBinding" on to each of your business objects. In the getter logic you could check each of the necessary properties and sub-objects to check for validity, non-nullness etc and return a bool. When you come to bind your repeater, write a simple linq statement that filters-out the invalid items (i.e. where IsValidForDataBinding = false). Having said that, I still think that writing a derived repeater control could be your easiest option.
Have you tried using string.isnullorempty("the string") to check for a value before referencing the property?
Here's a reference: MSDN