I’m referring to this article here
http://codebrief.com/2012/01/the-top-10-javascript-mvc-frameworks-reviewed/
In my current application I have two views. The first is the overall view which renders a table. The second view renders an individual row and is used by the main view. My row view could be separated into a separate file and used in any other component. In what way is this not composable? Perhaps I’m misunderstanding the terminology used in the article.
The author of that article is specifically referring to composable view templates, like Handlebars, in combination with the backbone view object.
He is essentially wanting to take a view-first approach to composition, where a template would define which views are composed in to the final view. This composition would also determine which objects are used to run the view.
For example, in EmberJS, you can configure a view template to be associated with a specific controller. Doing this, you can compose views in the template itself and the correct controller will be used. This is not possible with Backbone, even when using Handlebars – at least, not without some heavy customization. Backbone takes a “presenter-first” approach (to use the old Model-View-Presenter language) or a View-object first approach, where the view object itself controls which template is rendered.