How to nicely implement excelReponse, csvResponse or pdfResponse other than htmlResponse/jsonResponse?

[xluk9]

Hello, nice project. Finally, I don't have to wander around files to get to the business logic. So, in my application I usually respond with HTML, JSON and sometime I also need to return an Excel file or PDF file. What would be the right approach here other than implementing if/else in the controller? Is there a convenient way to provide an array like

protected $responseTypes =  [
   "expectPDF" => "pdfResponse"
    ...
];

where the key (in this case is expectPDF) is the method to call on $response like $response->expectPDF(). If that call return true, then invoke pdfResponse on the Action class. Obviously the user should implement somewhere expectPDF, either as macro (don't know if doable) or in the Action class itself.