Best Practice: Controller that handles multiple access methods (url/uri, ajax, post)

[eluser]Unknown[/eluser]
I am curious how others are coding controller functions that do one thing, but can be accessed through multiple methods. For the sake of example, imagine a controller for administrating categories.

1. You want to be able to delete categories via a hyperlink that is captured by javascript and handled by an ajax request, with a JSON response.
2. In the interest of being degradable, you want the hyperlink (something like "/admin/categories/delete/27") to be functional, in case javascript is turned off.
3. Elsewhere in the admin, you have a page that allows you to delete multiple categories or some other method that involves posting the category_id.

The most obvious three techniques I can think of are included below, but they all seem a bit clunky. How are you handing these types of situations in your controller code?

(These are all coded quickly for this post and not actually used, just a general idea...)

Possible Technique 1: One Function

Code:

function delete() {
    if(intval($this->uri->segment(4))) {
        $category_id = (int) $this->uri->segment(4);
        $this->category_model->delete($category_id);
        $this->load->view("admin/categories/delete_succes");
    } else {
        $category_id = (int) $this->input->post('category_id');
        $this->category_model->delete($category_id);
        if($this->user_agent->is_ajax()) {
            $json = array(
                "result" => "success",
                "message" => "The category was successfully deleted."
            );
            $this->load->view("json", $json);
        } else {
            $this->load->view("admin/categories/delete_succes");
        }
    }
}

Possible Technique 2: Separate functions

Code:

function ajax_delete() {
    $category_id = (int) $this->input->post('category_id');
    $this->category_model->delete($category_id);
    $json = array(
        "result" => "success",
        "message" => "The category was successfully deleted."
    );
    $this->load->view("json", $json);
}

function delete() {
    $category_id = (int) $this->uri->segment(4);
    $this->category_model->delete($category_id);
    $this->load->view("admin/categories/delete_succes");
}

function post_delete() {
    $category_id = (int) $this->input->post('category_id');
    $this->category_model->delete($category_id);
    $this->load->view("admin/categories/delete_succes");
}

Possible Technique 3: Utility Functions

Code:

function delete() {
    if(intval($this->uri->segment(4))) {
        $this->_process_delete($this->uri->segment(4));
    } else {
        $category_id = (int) $this->input->post('category_id');
        if($this->user_agent->is_ajax()) {
            $this->_process_ajax_delete($category_id);
        } else {
            $this->_process_delete($category_id);
        }
    }
}

Thanks in advance.