Display Nested categories

[eluser]shailendra[/eluser]
I want to display various project categories and no. of projects posted for each catgory. For example
Web & Programming(2)
-PHP(1)
-ASP(1)
Graphic Designing(2)
-Logo(2)
-Website Design(0)

I did this in php using following code. How do I do this in codeigniter?

Code:

<?php
    $category_details_model = new CategoryDetailsModel();
    $category_details_array = array();
    $category_details_array= $category_details_model->displayparentcategory(0);
    for($i=0;$i<count($category_details_array);$i++) {
        if(($category_details_model->noofactiveprojects($category_details_array[$i]->category_id,'public'))){
?&gt;
      <tr>
        <td height="20"> - <a >category_id?&gt;">&lt;?php echo $category_details_array[$i]->category_name ?&gt;</a>(&lt;?php echo $category_details_model->noofactiveprojects($category_details_array[$i]->category_id,'public') ?&gt;)</a></td>
      </tr>
&lt;?php
        }
}
?&gt;

Function to list all parent category

Code:

/* Function to list all parent category*/
public function displayparentcategory($parent_id){
  
    $query=sprintf("select category_id,category_name from category where parent_id=%d and active='y' order by category_name asc;",
    mysql_real_escape_string($parent_id));    
    //echo $query;

    $category_array  = array();
    $result   = mysql_query($query);
    $num_rows = mysql_num_rows($result);
    if($num_rows!=0) {
      while ($row = mysql_fetch_assoc($result)) {
        $category_details = new CategoryDetails;
        $category_details->category_id  = $row['category_id'];
        $category_details->category_name = $row['category_name'];
        //echo $category_details->category_name;
        $category_details->parent_id = $row['parent_id'];
        //echo $bid_details->proj_name;
        $category_details->date_time = $row['date_time'];
        //echo $bid_details->proj_name;
        $category_array[]=$category_details;

      }
      return $category_array;
    } else {
      return NULL;
    }
  }

Display all projects in a parent category

Code:

//Display all projects in a parent category
public function noofactiveprojects($category_id,$visibility){
            $query1= sprintf("select category_id from category where parent_id=%d;",mysql_real_escape_string($category_id));
            //echo $query1 ."\n";
            $result1 = mysql_query($query1);
            $total_num_proj=0;
            while($row1 = mysql_fetch_array($result1)){
                $category_id=$row1['category_id'];
                if($visibility=="all"){
                    $query2= sprintf("select * from projects where category_id=%d and status='open';",
                    mysql_real_escape_string($category_id));
                }
                else{
                    $query2= sprintf("select * from projects where category_id=%d and status='open' and job_visibility='%s';",
                    mysql_real_escape_string($category_id),
                    mysql_real_escape_string($visibility));
                }
                //echo $query2;
                $result2=mysql_query($query2);
                $num_proj=1;
                while($row2=mysql_fetch_array($result2)){
                    $projectposteddate=date('d-m-Y',strtotime($row2['date_time']));
                    $noofdays="+".$row2['job_display_days']." day";
                    $displayenddate=strtotime ( $noofdays,strtotime($projectposteddate));
                    //echo "displayenddate ".date('d-m-Y',$displayenddate);
                    $todaysdate=date("d-m-Y");
                    $difference=$displayenddate-strtotime($todaysdate);
                    $daysleft=round($difference / 86400);
                    if($daysleft>0){
                        $total_num_proj=$total_num_proj+$num_proj;
                    }  
                }
            }
            return $total_num_proj;
  }