Is there a way to filter an association?

[pmtarantino]

Let's say I have Teams and Players, with a Player belonging to a Team (with team_id), and each Player has a birthdate.

And I have,

$team = Team::find(1);
$team->players;

which gave me all the players. What if I want players born after 1990?

This doesn't work:

$team->players(array('conditions' => ...) ) ;

Thank you :)

[anther]

No there isn't in the current implementation.

Interestingly I am considering pushing another branch soon that I've worked on with a parallel "relationship" implementation that allows such things and it's built on top of the scopes branch. Instead of returning an array it returns a Relationship object that can be iterated over or have methods called on it that work similarly to scopes. (I also built it because currently php-ar has a few confusing to fix issues with through relationships and eager loading that I just wanted to not deal with anymore..).

If you're interested (and it's a pressing matter for you ;p) I can possibly speed up pushing a branch or some sort of separate project.
The interface ends up working kind of like what you have except it builds off of the scope stuff so...

$team = Team::find(1);
$team->players;
//Examples
$team->players->first(array('conditions'=>array('id'=>1)));
$team->players->all(array('conditions'=>array('order'=>'id ASC')));

My biggest gripe is that right now I coded it in camelcase and so I might just release it as a separate plugin.

[pmtarantino]

Hi Anther.

I think this is very critical.

Not because the conditions filters ( I really need them), but for limits. It is useless to retrieve associations if I can't paginate, for example.

I am using the stable version 1.0.0, so if you could release it as a plugin to be easily adaptable, that'd be great.

Thank you!

[pmtarantino]

Hi anther, any news on this? I really need it to continue with my project :-)

[anther]

Alright, I'll give you something to get started with, but essentially you need to use the following branch:
https://github.com/anther/php-activerecord/tree/advanced_relationships
(It's 100% compatible with the current master branch, the difference being that you can use scopes and the alternative relationships).

The exceptions, namespaces and such used are still from the other codebase so.. don't be too judgmental, you're essentially the second beta tester for this feature, and I'm interested in any bugs you find quickly, so I should be pretty active with getting things fixed.

I've used it on a site that I have that uses some pretty tricky through relationships, and I have unit tests over there to kind of ensure it.. but this is a quick "plugin" atm.

All of your models will need to inherit from a base model that looks something like this:

require_once (PHP_ACTIVERECORD_ROOT.'/lib/Relationship_Alternate.php');
class Universal_Model extends ActiveRecord\Model
{

    //This is to allow the relationship to be loaded.
    //This unfortunately takes precedence over the usual get_{method} but, that's because I didn't want to change the core yet
    public function & __get($name)
    {
        if($relationship = $this->hasRelationship($name))
        {
            $value = $relationship->getUsableReturnValue();
            return $value;
        }
        $result = parent::__get($name);
        return $result;
    }

    private static function translate_keys($array)
    {
        $relationships = array();
        foreach($array as $key => $relationship)
        {
            $replaced = array();
            $relationship_name = array_shift($relationship);
            foreach($relationship as $relationshipKey => $relationshipValue)
            {
                $replaced[lcfirst(static::camelize($relationshipKey))] = $relationshipValue;
            }
            if(isset($replaced['through']) && !isset($replaced['to']))
            {
                $replaced['to'] = $relationship_name;
            }
            $relationships[$relationship_name] = $replaced;
        }
        return $relationships;
    }

    public static function getPrimaryKeyField()
    {
        $first = true;
        $pk = static::table()->pk;
        return $first ? $pk[0] : $pk;
    }

    private static function camelize($word)
    {
        return preg_replace('/(^|_)([a-z])/e', 'strtoupper("\\2")', $word);
    }

    public static function belongsTo()
    {
        return isset(static::$belongs_to) ? static::translate_keys(static::$belongs_to) : array();
    }

    public static function hasMany()
    {
        return isset(static::$has_many) ? static::translate_keys(static::$has_many) : array();
    }

    public static function hasOne()
    {
        return isset(static::$has_one) ? static::translate_keys(static::$has_one) : array();
    }

    private $relationships = null;
    public function hasRelationship($name)
    {
        if($this->relationships === null)
        {
            $this->relationships = new JDO\Relationships($this);
        }
        $relationship = $this->relationships->hasRelationship($name);
        if($relationship)
        {
            return $relationship;
        }
        else
        {
            return false;
        }
    }

}

This base model essentially allows the translation of how the alternative relationships class wants to read data.

As far as usage instructions go... if you want to filter down results from the relationships, you need to update your relationship array.

Instead of

public static $has_many = array(
        array('event_owners','foreign_key'=>'event_id','class_name'=>'Event_Owner'),

You need to add 'asModels'=>true

When you do that, if you do..

$event->event_owners; //If no results, returns array(), if results, returns \JDO\Relationship
/* 
With the relationship object you can either use it directly in a foreach, or apply ->all, ->limit(5)->all, ->first.. etc.
*/

I wish I had more time to document the usage or to actually make it more normal, but if you do make some headway into it let me know what issues you're having and such and I'll be glad to answer!

[pmtarantino]

I will give it a try this weekend and let you know how it went! Thank you so much for this!

[pmtarantino]

I tried it but I get a Fatal Error:

Class 'JuggDataObjectException' not found in {root}lib\Relationship_Alternate.php on line 615

What's is JDO? I can't find it anywhere on the code.

[anther]

Hey, try pulling again. There was a missing class in the code that I didn't put into the relationship_alternate.php file.

[pmtarantino]

Well, I had to change line 615 of Relationship_alternate.php

from this

class JuggDataObjectException extends Exception{}

to

class JuggDataObjectException extends \Exception{}

Because it was looking for Class 'JDO\Exception' because of the namespace at the start of the file.

But it keeps me returning an error.

This is how I've got my model now:

class Instituto extends TwigModel
{
    static $has_many = array(
        array('usuarios',  'asModels' => true),
        array('alumnos', 'class_name' => 'Usuario', 'conditions' => array('tipo = "alumno"'), 'asModels' => true),
        array('profesores', 'class_name' => 'Usuario', 'conditions' => array('tipo = "profesor"') ),
        array('cursos'),
        array('materias'),
        array('curriculas',  'through' => 'cursos')
    );
}

and I'm calling it like this:

$Instituto->alumnos->limit(5)->all;

But it says:
Uncaught exception 'JDO\JDORelationshipException' with message 'Foreign Key not defined for this relationship'

Maybe is a mistake from my side, I don't know!

[anther]

Yeah, for some reason I never pushed through that missing slash, in my IDE it looks like it hit ctrl+z right before pushing my fixes =p.

In regard to your error, it doesn't currently go through the assumptions about class names and foreign keys that phpactiverecord goes through currently, so you just need to specify class_name and foreign_key for each relationship.

[pmtarantino]

Okay, so I added this:

'foreign_key' => 'instituto_id', 

But now returns the same error as before:
Fatal error: Call to a member function limit() on a non-object

[anther]

Hmm, suckage. Is $Instututo->alumos an empty array?
I think a quirk could be that if there are no alumos found, it returns an empty array instead of the relationship object, but I'm not sure if that's what's happening in this case.

[pmtarantino]

Undefined className in Relathionship_alternate on line 345

My models relationship looks like this now, by the way:

array('alumnos', 'className' => 'Usuario', 'class_name' => 'Usuario', 'foreign_key' => 'instituto_id', 'conditions' => array('tipo = "alumno"'), 'asModels' => true),

[anther]

Hmm, I think asModels should actually be false to have it return the relationship class, oops. The wording of that should definitely change a little bit.

I'm actually not sure as to why it should be giving you undefined className, as you clearly have it defined, it could possibly be a bug in the translate_keys method.

[pmtarantino]

Nop, doesn't work :'(

I know you have done a lot of work for this, but there is not a chance to pass an array with the options, just as find() does?

For example,

$instituto->alumnos(array(conditions, limit), and then that array to be appended to the original filter array?

[pmtarantino]

I am a bit lost with this, so sorry for many comments, but can I achieve the same with the scopes branches? I don't care if I have to do a little more code on my project, but I need to move forward and I am stuck right now because I can't limit the records I get in each page.