Whats the difference between JSF Custom Composite

2020-05-21 12:07发布

问题:

i want to build a custom JSF Component. Now i read some docs from oracle and saw a few code Examples. The problem is i am a bit confused:

It seems there are two ways to build a custom component with JSF 2.0+. As far as i understood since JSF 2.0 i can use these Composite Components to build my own component.

But do they have any disadvantages compared to the "Classical" Component ?

My Component will be rather complex do i loose anything (beside downwards compability) when i use Compisite Components ?

For example my Component will have some work todo in java, is this possible with Composite Components ?

回答1:

A composite component is useful if you want to represent a bunch of closely related existing tags/components/HTML as a single and reuseable component by pure XML means.

A custom component would be the only way when there are no standard JSF tags/components available to achieve the requirement. E.g. <input type="file">, <input type="range">, etc. Note that such a custom component can in turn be used in a composite, whenever desireable.

Makes totally sense, right?

You can create a so-called "backing component" class extending UINamingContainer (or at least implementing NamingContainer) and bind it to the composite by <cc:interface componentType>. You can find several examples in my answers here.

Do however note that sometimes a composite component isn't suitable, you'd need to create a tag file instead. For example when you want to have a custom and reuseable <h:column>.

See also:

  • When to use <ui:include>, tag files, composite components and/or custom components?