Ajax driven content using CodeIgniter

I'm making an web that is a single-page website interacting with the server through Ajax in CodeIgniter. The general coding is of the following type:

controller (user.php):

public function get_user_content() {
    $id = $this->input->post('id');
    $hits = $this->user_model->user_data($id);
    $s = '';    
    foreach ($hits as $hit) {
       $s .= $hit->name;
       $s .= $hit->age;
    }
    echo $s;
}

model(user_model.php):

function user_data($id) {
   //do sql operation
   return $query->result();
}

view:

...
...
<a href="#" id="23" class="user-data">Click here for user details</a>
...
...

javascript:

('.user-data').click(get_user_data);
....
....
function get_user_data(response) {
    return $.ajax({
        type: "POST",
        url:  "<?php echo base_url();?>index.php/user/get_user_content",
        data: { id: this.id },
        success: function(response) {
            $("#somediv").append(response);
            $(".someclass").click(another_function);
        },
        error: function(error) {
            alert("Error");
        }
    });
}

So, looking at the above javascript, there are separate functions for all actions that send some data to the server and the particular html content is updated via Ajax.

I had the following questions (I'm just new to this stuff):

1. Is there any better way of doing ajax in javascript than my implementation.
2. I'm not using the concept of views in CodeIgniter. I just `echo` results through my controller functions that gets embedded in javascript. This is because I want dynamic update in my app. It is a single page and there is no concept of new-page/new-tab. Is there any better way? 

I'm not aware of any open-source projects that might make it easier/more optimized.