jQuery post call with codeigniter fails - php

Question

I am trying to delete the element with post jquery request:
$(function(){
//The element
// <a data-id="39" data-toggle="modal" href="#delete"><i class="icon-trash"></i>
Delete</a>
$('.delete').on('click',function(){
var id= $(this).attr('data-id');
$.post('task/delete', { id: id }, function(data) {
alert('Task deleted!');
})
.success(function(){ alert('Task deleted!'); })
.complete(function(){ alert('Task completed!'); })
.error(function(){ alert('Error was found!'); });
})
});
My controller is called task and the function inside it is called delete.
class Task extends CI_Controller {
public function delete()
{
$this->load->model('tasks_model','task_delete');
$this->task_delete-> deleteTask($_POST['id']);
}
}
The model is quite simple.. it simply deletes the record.
public function deleteTask($task_id)
{
$task_id = mysql_real_escape_string($task_id);
$this->db->query("DELETE FROM tasks WHERE task_id = ?", array($task_id));
}
I get two messages..one is error and one is delete...
Another thing that I want to avoid is someone posting the id to the controller task .. which will delete the records one by one automatically, is there a way to avoid this too?

Answer 1

Your controller method should look something like this
public function delete()
{
// Do user validation here
$this->load->model('tasks_model');
$this->tasks_model->task_delete($this->input->post('id'));
return "task deleted";
}
And you models method like this
public function task_delete($task_id)
{
$this->db->where('task_id', $task_id);
$this->db->delete('tasks');
}
As I would recommend validating the user where the comment says you should, and using CI's active record library where you can to increase portability to a different DB.
Edit
To show PHP errors (and maybe MySQL errors if they are turned on).
error_reporting(E_ALL);
To ensure the task is deleted, do this (which is not as efficient).
public function task_delete($task_id)
{
$this->db->where('task_id', $task_id);
$this->db->delete('tasks');
$this->db->from('tasks');
$this->db->where('task_id', $task_id);
$query = $this->db->get();
if ( $query->num_rows() > 0 )
{
return FALSE;
}
else return TRUE;
}
And then do something with the returned boolean in the controller.

Answer 2

You haven't used the function name in your controller it should be:
$this->task_delete->deleteTask($id);

Answer 3

To avoid someone posting all IDs and deleting all tasks, you should only delete tasks which belong to this user.
I'm guessing you save each task so it belongs to a specific user, right? So in your delete query, you can make it so you run a DELETE WHERE task_id={task_id} AND user_id={user_id}. The user_id is something you'll have saved in the session.
As a side note, when running database queries, you can bind the parameters, which means CI takes care of making the parameters safe. So you can amend your query above to be like this:
$this->db->query("DELETE FROM tasks WHERE task_id = ?", array($task_id));
You can read more on this here: http://codeigniter.com/user_guide/database/queries.html at the bottom (Query Bindings section).
As for your error of getting both an error and a success message, there might be a few different things going wrong. I'm not sure if something's gone wrong when copying the code, but you have an error in the PHP code:
$this->load->model('tasks_model','task_delete');
$this->task_delete($id);
Should be:
$id = $this->input->post('id'); // the data is posted, it won't be passed in as an argument to the controller function
$this->load->model('tasks_model','task_delete');
$this->task_delete->deleteTask($id);
And your query also seems to have a mistake, so it would be better to make it as I mentioned above.