Composite Input Components in JSF

Composite components are a great feature of JSF 2.0. The canonical example is a login component with fields for the username and password: This has been well explained elsewhere. But here is what always baffled me. I want to have a composite date component, with three menus for day, month, and year. But I want it to have a single value of type java.util.Date, so I can use it like this: and not Why do I care? My classes aren't all made up of strings and numbers. I use objects when I can. My User class has a property birthDay of type java.util.Date. I don't want to write boring code to take dates apart and put them back together. I want to use bean validation for the date property, with a @Past or @Future annotation. I asked around and people told me that this couldn't be done with composite components—I'd have to write an actual custom component. But, as I discovered, it is not so. With a small dose of knowledge of the JSF lifecycle, and the poorly documented technique of backing components, this is actually pretty easy. Here goes. When you make a composite component, it is normally turned into a UINamingContainer that contains the child components in the implementation. But you can also force a different component to be used, provided it implements the NamingContainer marker interface its “family” is "javax.faces.NamingContainer" (don't as...

Date: January, 30 2010
Url: http://www.java.net/blog/cayhorstmann/archive/2010/01/30/composite-input-components-jsf

Others News