I can see that calling it render might be misleading, but Phoenix.View’s are not about template rendering per se. In fact all the template rendering functionality comes from Phoenix.Template (see the render_template I showed here) and it just happens to be one of the things a view does as part of it’s job.
Phoenix.View’s are about mapping the data your controller aggregates to the format they’re returned in as the response of the http request. And that’s needed for any kind of response be it an html page, a json document, a xml document or any other one you might be using. Some of them might be created using templates others might not. Granted for json documents it can be as easy as just encoding the data as is, but it’s not always that easy.
Like you might have a user struct and in one place you like to encode it with information about the user being an author (name and num. of publications), while at another place the same user struct might be encoded for authorization purposes (e.g. role and permission information). This is logic phoenix wants you to put into a View and not do it in controllers. The controller should just care to retrieve the user struct.
Another thing you might do in a view is hide specific fields. Like for an access controlled file you might not want to hide the password a user needs to download it. Again the controller is for the data retrieval, but not for knowing how to modify the data for sending in the response.
Edit:
The filename (e.g. “index.json”) is more of a “render the “index” json document with data …”. The filename format just makes it super convenient if you happen to use templating.
