cardinality issue

[Former Member]

Hello ,

I created a node emp and with attribute name in the component controller and gave the cardinality as 0..1 and selection 0:.1 .

and in the view i gave UI element Input_field for the attribute name.

But is giving dump when im executing with the follwoing message :

The following error text was processed in the system ARD : Adapter error in &VIEW_ELEMENT_TYPE& "IN" of view "YEXAMPLE.MAIN": Context binding of property VALUE cannot be resolved: Node MAIN.1.EMP does not contain any elements

Could you please say why im getting dump .

Also when im trying to give the cardinality as 0..n to also im gettting the dump.

Plesae give info about the same.

Edited by: meshack prasan appikatla on Jan 25, 2010 2:27 PM

Edited by: meshack prasan appikatla on Jan 25, 2010 2:30 PM

[thomas_jung]

That is becuase you don't have an element in that node. 0:1 and 0:n both allow no element. Cardinality isn't really your problem directly. It is the fact that you need an inital element in that node.

[Former Member]

hello thomas,

But why is it required to have the Initial element . In the node there is only attribute name ?

Can you please elaborate?

Thanks

[thomas_jung]

>

> hello thomas, 
> 
> But why is it required to have the Initial element . In the node there is only attribute name ? 
> 
> Can you please elaborate? 
> 
> Thanks

Without an element there is nothing for the UI element to bind to. It doesn't matter if you have one attribute or many - you still need an element for the binding to work. All data binding (even to the context root) technically must go through a context element.

[Former Member]

Thomas ,

Thanks for your information . So in which case we can use the cardinality as 0..1 or 0..n ?

thanks

[thomas_jung]

You can use them in a variety of instances, but if you are going to have 0 elements know that you can't bind single element UI elements (like inputField) to the context node.

[Former Member]

For some UI elements like Drop Down List you can cardinality as 0..N

Lets say you plan to display all the contracts of BP in a DDL, it might be possible that BP doesn't have any contract in his name or has multiple contracts, in that case cardinality will be 0..N