连接表中的HABTM附加字段

Question

I'm having some trouble with a HABTM association.

What I'm trying to do is the following:

Template HABTM Medium Pages HABTM Medium

To do this I created the join table object_media and wanted it to have object_id, medium_id and model fields. the page id or template id would go into the object_id field and the model would have either 'Page' or 'Template'. By doing this I would be able to connect any model with my Medium model. (Medium = media, all images, videos, documents, etc get saved there). Then I can just pass conditions into the HABTM relation to get only media for that specific model. eg: ObjectMedium.model => 'Template' would return all media connected to template.

In short: I want 1 table that links any model to any medium.

Template.php

class Template extends AppModel{
    public $name = 'Template';

    public $hasMany = array(
        'TemplateColumn'
    );

    public $hasAndBelongsToMany = array(
        'Medium' => array(
        'className' => 'Medium',
        'joinTable' => 'object_media',
        'foreignKey' => 'object_id',
        'associationForeignKey' => 'medium_id'
        )
    );
}

Medium.php

class Medium extends AppModel{
    public $name = 'Medium';
    public $useTable = 'media';

    public $hasAndBelongsToMany = array(
        'Template' => array(
        'className' => 'Template',
        'joinTable' => 'object_media',
        'foreignKey' => 'medium_id',
        'associationForeignKey' => 'object_id'
        )
    );
 }

However, feeding it the following data wouldn't even save the medium:

 Array
    (
[Template] => Array
    (
        [name] => 
    )

[TemplateColumn] => Array
    (
        [0] => Array
            (
                [block] => 0
                [column] => 0
                [grid] => 7
            )

        [1] => Array
            (
                [block] => 0
                [column] => 1
                [grid] => 5
            )

        [2] => Array
            (
                [block] => 1
                [column] => 0
                [grid] => 6
            )

        [3] => Array
            (
                [block] => 1
                [column] => 1
                [grid] => 6
            )

    )

[Medium] => Array
    (
        [0] => Array
            (
                [name] => 7917196b42c3626c10ab024bbafb8171
                [src] => 134a16c2202ff2b0c9b1c51dddb1bcfc.jpg
                [type] => Image
            )

    )

This gives me the following queries:

INSERT INTO `templates` (`name`, `modified`, `created`) VALUES ('', '2011-11-20 15:18:46', '2011-11-20 15:18:46')
SELECT `ObjectMedium`.`medium_id` FROM `object_media` AS `ObjectMedium` WHERE `ObjectMedium`.`object_id` = 30
INSERT INTO `template_columns` (`block`, `column`, `grid`, `template_id`, `modified`, `created`) VALUES (0, 0, 7, 30, '2011-11-20 15:18:46', '2011-11-20 15:18:46')
INSERT INTO `template_columns` (`block`, `column`, `grid`, `template_id`, `modified`, `created`) VALUES (0, 1, 5, 30, '2011-11-20 15:18:46', '2011-11-20 15:18:46')
INSERT INTO `template_columns` (`block`, `column`, `grid`, `template_id`, `modified`, `created`) VALUES (1, 0, 6, 30, '2011-11-20 15:18:46', '2011-11-20 15:18:46')
INSERT INTO `template_columns` (`block`, `column`, `grid`, `template_id`, `modified`, `created`) VALUES (1, 1, 6, 30, '2011-11-20 15:18:46', '2011-11-20 15:18:46')

Any Ideas of what is going wrong? And how to add the model name in the join table?

Answer 1

also take a look at the many answers on the different plattforms to this very same topic: http://www.google.de/search?gcx=c&ix=c2&sourceid=chrome&ie=UTF-8&q=habtm+extra+join+table

this might be most helpful: http://nuts-and-bolts-of-cakephp.com/2008/09/24/saving-extra-fields-in-the-join-table-for-habtm-models/