Play框架2中的条件视图渲染

Question

I have a very simple question I am not sure how to solve. I need render a different template in my Play controller depending on if the view template exists.

One of the template is build by an external sbt task and depending on the project state It might not be there as an external dependency based on this I need to render an other template.

Is there an easy way to check if a view template class exists in the Controller ?

Answer 1

Its a bit ugly since since Play templates are compiled into classes you can try to load the class.

You can try to load the class using Class.forName. If it exists, then you can use it. Since exceptions aren't really recommended for flow control due to performance considerations, you want want to cache the results of this lookup in a singleton somewhere.

        try {
            Class.forName("views.html.index.class");
        }
        catch(ClassNotFoundException e) {
            //no here
        }