[eluser]mddd[/eluser]
I think that in reality you will always need to do things to your data before you can output information. If your controller is going to output Json, you probably have to do some other stuff to that data then when you were outputting Html.
So my guess is that the generic methods (_png, _html, _json etc) that you would put in your MY_Controller class would not have much use. Like the '_html' method: what more can that method do than load a view, with the information it gets from some other function in your controller? You still need to load information, and maybe process that information before you can send it to the _html function. If that's all done, then why not put the 'this->load->view' in the Controller too?
Pretty much the same goes for the handling of post information or segment information (note: you'll probably need both in every controller so this is not a real choice between the two). Why make these generic 'input handling functions'? What can they do? They can take all the parts from a request and give them to another method in your Controller. That is completely unneccessary because there are already functions in CodeIgniter to get those POST variables and segment values.
So, I get the feeling that you want to build a 'framework in a framework' by making all these methods that, in the end, won't really help to DO anything. The real 'doing' is still going to be in the regular controller methods, supported by calls to libraries and models.
I hope this makes sense.
