Question

I have been making good use of custom properties withing custom controls. Is there such thing as custom methods? Say I want something to happen in a CC. A good example is the show method of the dialog box extension. If I have a cc with a extension dialog inside, I want my custom control to have a Show method which insulates the end user programmer from the extension pages Shoe method.

Is there anyway to do this?

Answer 1

At runtime, all Custom Control elements become instances of the UIIncludeComposite class; as such, there are many built in methods that you can call against any given control instance, but there is no way to specify custom methods, as opposed to custom properties.

There are, however, at least two ways you could achieve the result you’re after:

1. Convert your Custom Control to a component (this NotesIn9 episode describes the simplest approach to this process). Once you’ve migrated the class that Designer generated to one that won’t get overridden every time you build your NSF, you can add custom methods without fear that the next build will just wipe them out again. Since Custom Controls are essentially just IBM’s implementation of the JSF 2.0 notion of “composite components”, you could also create a component from scratch that has the same behavior as your existing Custom Control but also supports custom behavior. Note that either approach does not necessarily require that you create an OSGi library… you can define these components directly in an NSF; you only need to push them to a library if you want to reuse them across multiple NSFs without having to copy the various files to each.

2. In the custom properties for your control, include one property that accepts an API object. In other words, you could create any object (say, a Java class or SSJS object) that supports the custom methods you wish to define, and pass that object to the control. You could then call those methods by getting a handle on the object via the CC’s property map.

For example:

<myCC id="myCustomControl" API="#{someObject}" />

Assuming whatever #{someObject} resolves to includes a show() method, you can call that method by getting a handle on the instance that has been passed to the control:

var cc = getComponent("myCustomControl");
var ccProperties = cc.getPropertyMap();
var ccAPI = ccProperties.get("API");
ccAPI.show(cc);

In the above example, I’m passing the actual Custom Control to the show() method, because the object itself isn’t aware of the Custom Control it was passed to. So if that method needs to get a handle on its children to toggle their rendered property, for example, then it needs some other way of determining its context.