# sfPropelActAsPolymorphicBehaviorPlugin plugin

The `sfPropelActAsPolymorphicBehaviorPlugin` is a symfony plugin that provides support for polymorphic keys in Propel objects.

## Features

  * Easily access a foreign record based on a two-column polymorphic key.
  * Works alongside Propel's native support for [single table inheritance](http://propel.phpdb.org/trac/wiki/Users/Documentation/1.2/Schema#columnelement) when using `schema.xml`.

## Limitations

As of now this plugin only knows how to access a parent record related to a child record by polymorphic key. Also, foreign objects must be saved to the database before being passed to the `setPolymorphicHasOneReference` method. More robust functionality is in development, hence the alpha designation. The API is subject to change.

## Installation

  * Activate the behavior for one of your Propel models:

      
    [php]
    <?php
    
    // lib/model/Milestone.php
    class Milestone extends BaseMilestone
    {
    }
    
    $hasOneKeys = array('assigned_to' => array('foreign_model' => MilestonePeer::ASSIGNED_TO_TYPE,
                                               'foreign_pk'    => MilestonePeer::ASSIGNED_TO_ID));
    sfPropelBehavior::add('Milestone', array('sfPropelActAsPolymorphic' => array('has_one' => $hasOneKeys)));
      

## Usage

The plugin will add two methods to your OM class: `getPolymorphicHasOneReference` and `setPolymorphicHasOneReference`. It's easy to create wrappers for these methods for each of your polymorphic keys.

      
    [php]
    <?php
    
    public function getAssignedTo()
    {
      return $this->getPolymorphicHasOneReference('assigned_to');
    }
    public function setAssignedTo($assignedTo)
    {
      $this->setPolymorphicHasOneReference('assigned_to', $assignedTo);
    }
      

### Setting a polymorphic reference

      
    [php]
    <?php
    
    $person = PersonPeer::retrieveByPK(37);
    
    $milestone = new Milestone;
    $milestone->setPolymorphicHasOneReference('assigned_to', $person);
    
    // or, if you wrap the setter method with a key-specific method ...
    $milestone->setAssignedTo($person);
    
    $milestone->save();
      

### Retrieving a polymorphic reference

      
    [php]
    <?php
    
    $milestone = MilestonePeer::retrieveByPK(108);
    
    $assignedTo = $milestone->getPolymorphicHasOneReference('assigned_to');
    
    // or, if you wrap the setter method with a key-specific method ...
    $assignedTo = $milestone->getAssignedTo();
      

## Changelog

### 2007-09-13 | 0.0.1-alpha

Initial public release.

  * Unit tests not in place.
  * PEAR package not in place.
  * Supports only m-to-1 relationships.
  * Foreign objects must be saved before being passed to `setPolymorphicHasOneReference`.

## Maintainers

Kris Wallsmith