如何在下拉列表中加载类别名称

Question

I want to load only main categories(not sub-categories) name in drop down list. i have tried enough but could not succeed. There are numbers of answer on this site and I tried to solve my problem in that way but can't. The category table is given below, it is same as on cakephp docs in Tree.

categories table attribute

id | parent_id | lft| rght |name |

i tried these techniques given on following links How to populate drop-down list with database values in CakePHP

full code of controller to create category is given below.

 if ($this->request->is('post')) {
            $this->Category->create();
            if ($this->Category->save($this->request->data)) {
                $this->Session->setFlash(__('Category has been saved.'));
                return $this->redirect(array('action' => 'index'));
            }
            $this->Session->setFlash(__('Unable to add Category.'));
        }
        else 
          $categories = $this->Category->find('list');
          $this->set(compact('categories'));
           return $this; 
      }

code of category.ctp is

  <?php echo $this->Form->create('Category'); ?>
        <fieldset>
        <legend><?php echo __('Add Category'); ?>
        </legend>
        <?php
                $form->input('id');
        //      echo $this->Form->input('id');
                echo $this->Form->input('name');

        ?>
        </fieldset>
        <?php echo $this->Form->end(__('Submit')); ?>
        </div>

now please suggest me solution to load data in drop down list.

Answer 1

Stick to the conventions and everything's going to be ok. I assume you need the list in your add form to select the parent category (your intent btw is something that you should clarify in your question).

With trees you want to order by lft, so if you use find('list') you'll have to pass that in the order option, and in order to retrieve only the top-level categories you'll have to pass in a condition that matches all categories where parent_id is null (or the ID of a parent category whichs sub-categories are your "main" categories).

Controller

$parents = $this->Category->find('list', array(
    'conditions' => array(
        'Category.parent_id' => null
    ),
    'order' => array(
        'Category.lft' => 'asc'
    )
));
$this->set('parents', $parents);

View

echo $this->Form->input('parent_id');

For more information see

• http://book.cakephp.org/2.0/en/core-libraries/behaviors/tree.html
• http://book.cakephp.org/2.0/en/core-libraries/helpers/form.html#creating-form-elements