cakePHP hasOne relationship not auto completing dropdown field

Question

I'm trying to implement a hasone relationship between 2 models, but I can't have the 'add' form autocomplete with the possible options in the second model (the one that belongsTo the first one). This is my code:

- model 1: item.php

<?php
class Item extends AppModel{ 

    var $name = 'Item';
    var $primaryKey = 'id';
    var $hasOne = 'CoverImage';
    }
?>

- model 2: cover_image.php

<?php
class CoverImage extends AppModel{ 

    var $name = 'CoverImage';
    var $primaryKey = 'id';
    var $belongsTo = array(
                 'Item' => array(
                    'className' => 'Item',
                    'foreignKey' => 'item_id'
                        )); 
}
?>

- add view of model 2: add.ctp

<?php echo $this->Form->create('CoverImage',array('url' => array('controller' => 'admins', 'action' => 'add')));?>
    <fieldset>
        <legend><?php __('Info'); ?></legend>
    <?php
        echo $this->Form->input('item_id');
        echo $this->Form->input('description');
    ?>
    </fieldset>
    <?php echo $this->Form->end(__('Create', true));?>

For what I see in Cake's documentation, with this relationship, in the add view I should see a dropdown list in the item_id field to be able to select to which item does this CoverImage belongs to, but the dropdown is empty (and yes, I have some items in the items table already).

Maybe I'm missing something or I've done something wrong, but I can't figure it out. Thanks so much in advance for any clues!

EDIT

One think I've just realized is that if I do this:

echo $this->Form->input('item_id', array('type'=>'text'));

instead of this:

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

I can add/edit the *item_id* field, I can see its value in the text box. However, if I leave the other one, I just see an empty dropbox and when I try to add/edit a CoverImage, it doesn't work, it just shows an empty white page, not even with errors...

Maybe this is a lead to something...

Try: echo $this->Form->inputs(); It is an automagical way to generate form fields for all attributes, at once. It's not a straight answer/solution but maybe it helps you finding clues. — Bart Gloudemans

deceze deceze · Accepted Answer · 2011-06-23T00:05:15

In order for that to work you have to create a list of possible options in the controller. That does not happen automatically.

public function add() {
    $items = $this->CoverImage->Item->find('list');
    $this->set(compact('items'));
}

The FormHelper only automatically infers that the field item_id should be populated by the options in the variable $items (plural, no _id).

Do be careful that Items that already haveOne CoverImage should not be part of that list. find('list', array('conditions' => array('CoverItem.id' => null))) will probably* take care of that, but you'll need to recheck just before saving as well, or you need to rethink your associations.

* Not sure off the top of my head whether that'll work for 'list' searches.

cakePHP hasOne relationship not auto completing dropdown field

2 Answers