Step 6. Create a Grid
(using Model, View, Controller objects)

The technique stated on Step 4 and Step 5 works well if data is loaded from a single DB table. But if data requires more difficult loading and saving, it's better to create a separate model class.

As an example, let's create a model object for the grid we built on Step 4.

We will divide the step into 3 substeps:

• Step 6.1. Configuring the Model object
• Step 6.2. Configuring the View object
• Step 6.3. Configuring the Controller object

In our model we will specify functions for:

• Getting an array of data items;
• Getting an individual properties of a data item;
• Processing Insert/Update/Delete operations;
• Validating data before saving.

1. In the "models " folder create a new file and name it event_model.php
2. Open the "event_model.php " file and add the following code there:
   
   

   "models/event_model.php" file

   <?php
    
   class Event_model extends CI_Model {
       var $event_name;
       var $start_date;
       var $end_date;
    
       function __construct()
       {
           parent::__construct();
       }
       //returns an array with data
       function get($request){
           $query = $this->db->get("events");
           return $query->result_array();
       }
       //the function takes values of the row data
       protected function get_values($action){
           $this->event_name   = $action->get_value("event_name");
           $this->start_date   = $action->get_value("start_date");
           $this->end_date     = $action->get_value("end_date");
       }
       //inserts a new event
       function insert($action){
           $this->get_values($action);
    
           if ($this->validate($action)){ 
              $this->db->insert("events", $this);
              $action->success($this->db->insert_id());
          }
       }
       //updates an event
       function update($action){
           $this->get_values($action);
    
           if ($this->validate($action)){ 
               $this->db->update(
                   "events", 
                   $this, 
                   array("event_id" => $action->get_id())
               );
               $action->success();
           }
       }
       // validates an event before saving
       function validate($action){
           if ($this->event_name == ""){
               $action->invalid();
               $action->set_response_attribute(
                   "details",
                   "Empty text is not allowed"
               );
               return false;
           }
           return true;
       }
       //deletes an event
       function delete($action){
           $this->db->delete("events", array("event_id" => $action->get_id()));
           $action->success();
       } 
   }
   ?>

We won't create a new view and will use the view file specified on Step 4.

And let's create a new controller that will process our model.

The difference between the current controler and the controller file of the Step 4 lies is 2 commands:

$this->load->model("event_model");// loads the model
$connector->useModel($this->event_model);//applies the model

The commands allows us to load our model and apply it in the project.

1. In the "controllers " folder create a new file and name it "gridmodel.php "
2. Open the "gridmodel.php " file and add the following code there:
   
   

   "controllers/gridmodel.php" file

   require_once("./dhtmlx/connector/grid_connector.php");
   require_once("./dhtmlx/connector/db_phpci.php");
   DataProcessor::$action_param ="dhx_editor_status";
    
   class GridModel extends CI_Controller {
       public function index()
       {
           //grid's view
           $this->load->view('grid'); 
       }
       public function data()
       {
           //data feed
           $this->load->database();
           $this->load->model("event_model");
    
           $connector = new GridConnector($this->db, "PHPCI");
           $connector->configure(
               "events", 
               "event_id", 
               "start_date, end_date, event_name"
           );
           $connector->useModel($this->event_model);
           $connector->render();
       }
   }