Saturday, January 17, 2009

extra field!!!

I was doing a custom component in JSF, and I kept getting an extra input field with the clientId as the id attribute, and I did not know why. I searched the web and did not find anybody who had ever encountered this. Since it always came last in the component I could not even figure out a way to hide the thing because any JavaScript I put in the component came prior to the existance of the field. I do not do anything in my encodeBegin() that asks for this.

Then I started wondering if extending the UIInput component required something that I was not doing; either that I figured or it was putting this darn extra field.

After studying other custom components' code, it finally occurred to me that if you extend a custom component (like UIInput) you have to be mindful of what methods that component implements, and what it does in those implemented methods. Then you have to decide if you still want that particular part of the component you are extending.

In my case, UIInput used encodeEnd() method to actually produce its field, so I just overrode encodeEnd() and made it do nothing. Then I started to wonder why I even was extending UIInput instead of UIComponent or something...

I guess that is another lesson...

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