CodeIgniter best practices: where to store jQuery/Ajax callback script? - php

Question

I'm working with CodeIgniter 3 and I would have some advices about where storing scripts. I want to call with jQuery a php script that will send JSON datas to my Javascript function.
How to do a connection with my database inside this script using CodeIgniter database config file?
Here is my jQuery callback structure :
<?php
session_start();
header('Content-Type: text/json');
error_reporting(E_ALL);
ini_set("display_errors", 1);
$callback = array();
echo json_encode($callback);
I've stored this script in app/callback folder that I have made, but I don't know if I should store it outside app folder or not... How do you structure your CodeIgniter's projects?
Thanks for your advices :)

Answer 1

setup;
in your application/config/database.php configure your database connection
in your application/config/autoload.php ensure that the database library is enabled
here for more info for database setup
model;
in application/models/ create your thing_model.php which functions for accessing your database. for this example public function get_data() this function would produce your database JSON data output when called
here for more info to query your database
controller;
in your application/controllers/thing.php create an ajax function;
public function ajax()
{
if ($this->session->loggedin && $this->input->is_ajax_request()){
$action = $this->uri->segment(3);
if ($action === "pull"){
$forms = $this->thing_model->get_data();
//actions here
}
if ($action === "test"){
//actions here
echo "hello world!";
}
} else {
redirect('/homepage');
}
}
whats happening;
if ($this->session->loggedin && $this->input->is_ajax_request()){
here you are checking for security and that the request is ajax in nature
$action = $this->uri->segment(3); is grabbing a segment from the URI for actioning. eg. http://example.org/controller/ajaxmethod/this_action
if ($action === "pull"){ is returning data if your ajax was invoked to http://example.org/thing/ajax/pull
ajax;
in the jquery JSON ajax in your .js file (load the .js file in the footer of your view)
$('#buttonAction').click(function() {
//Jquery Ajax code here
$.ajax({
method: "POST",
dataType: "json",
url: global_path + "thing/ajax/pull",
data: { user_id: "1", data: "ABC" }
})
.done(function( data ) {
//process your JSON data here
});
});
whats happening;
jquery ajax datatype see here
url: global_path + "thing/ajax/pull", calls your controller ajax() method with the pull action.
notes;
in your __construct for the controller i would recommend putting in some testing here to secure only ajax requests to your function, and not the others for strict operations and unwanted unknowns.
you could put ajax to another controller if it suits your application. but this can create security headaches with duplicating checks etc.

Answer 2

If you want to call backend functions from jQuery you have to go with AJAX. Check docs here. See a simple example below.
$.ajax({
method: "POST",
url: "PATH_TO_YOUR_CONTROLLER_FUNCTION",
data: { field_name1: "Field value 1", field_name2: "Field value 2" }
}).done(function( msg ) {
console.log(msg);
});
If you have this script in your view (which is a php file), you'll be able to use php functions to set the path. For example:
url: "<?php echo base_url('your_controller/your_function')?>"
The db connection and all logic stays in the controller and is implemented as usual.