SPARQLModel for Laravel (PHP)

A model for Laravel 4, that can manage object through a graph database using SPARQL endpoint.

How to use this model

First of all you need to have access to an endpoint. If you need to perform INSERT and DELETE, make sur you have these privileges.

Install

To install SPARQLModel in your Laravel 4 project, update your composer.json file by adding this line in the require array:

    "legrand/sparqlmodel": "dev-master"

After that you can open a terminal in the root folder of your project and run composer :

    composer update

it will add the package in your project.

Configuration

This model need some configurations to work. Create a 'sparqlmodel.php' file in app/config and add this arry :

    <?php

    return array(

            'endpoint' => 'http://localhost:8890/sparql',
            'graph' => 'http://localhost:8890/DAV',

            'status' => 'http://uri.for/property/status',
            'created' => 'http://uri.for/property/created',
            'updated' => 'http://uri.for/property/updated'
    );

The endpoint is the URL to communicate with the graph database through SPARQL, and graph is the URI of the graph that you are using for your application.

Example

Now you can create a simple model. For example here a Like model :

    use Legrand\SPARQLModel;

    class Like extends SPARQLModel {

            public $hash                    = null;
            protected static $baseURI       = "http://semreco/like/";
            protected static $type          = "http://semreco/class/Like";
            protected static $mapping       = [
                    'http://semreco/property/resource' => 'topic',
                    'http://semreco/property/performed' => 'performed'
            ];

            public function generateID()
            {
                    if(!isset($this->hash) || !is_string($this->hash) || $this->hash == '') throw new Exception("There is no hash string to generate the unique URI");
                    return $this::$baseURI . $this->hash;
            }

            public function save($moreData=[])
            {
                    if(!isset($this->performed)) $this->performed = date('Y-m-d H:i:s', time());
                    parent::save($moreData);
            }
    }

Here you can some attributes that you need to specify

• $baseURI : Here you give the base of the URI, the part taht identify the like will be append at the end of this string
• $type : Here you give the class URI that define the object
• $mapping : You give here an array where a property uri correspond to an attribute name, so for examp;e to get the date of the like you can do $like->performed

There are also some some methods that are overided here :

• generateID() : as data id are URI, we cannot generate a unique id (with increment for example) so you need to return here the URI that correspond to your resource
• save($moreData=[]) : here this method have been overrided to save automatically the date of this like

Now we can create a User model :

    <?php

    use Legrand\SPARQLModel;

    class User extends SPARQLModel {

            protected static $baseURI       = "http://semreco/person/";
            protected static $type          = "http://xmlns.com/foaf/Person";
            protected static $mapping       = [
                    'http://xmlns.com/foaf/lastName' => 'lastname',
                    'http://xmlns.com/foaf/firstName' => 'firstname',
                    'http://xmlns.com/foaf/mbox' => 'email'
            ];
            protected static $multiMapping  = [
                    'http://semreco/property/like' => [
                            'property' => 'likes',
                            'mapping' => 'Like', //should be the name of the corresponding class
                            'order' => ['DESC', 'performed'], //performed is in the mapping of the Like model
                            'limit' => 5
                    ]
            ];

            public function generateID()
            {
                    if(!isset($this->username)) throw new Exception("There is no username to generate the unique URI");
                    return $this::$baseURI . $this->username;
            }

            public function addLike($uri)
            {
                    if(!$this->inStore) return; //isStore is usefull to see if the current object exist in database

                    $like = new Like();
                    $ex = explode('/', $uri);
                    $like->hash = $ex[count($ex)-1] . '_(' . $this->username . ')';
                    $like->topic = $uri;
                    $like->save(); // we save in database the like object

                    if(!isset($this->likes) || !is_array($this->likes)) $this->likes = [];

                    $this->likes[] = $like;

                    $this->link($like); //here we add the like to the current user, this method will user the $multiMapping attribute
            }
    }

Here another attribut is used to make a link between the user and his likes :

• $multiMapping : need a complexe array. The URI of the property need another array with : - property : the name of the attribute - mapping : the name of the class, - order : an array with first value the ordering type and second value the name of the attribute - limit : the number of resources to get

You can see also that a method addLike get the uri of the resource that have been liked by the user to create a like and add it to the user's likes.

Usage

Now we can use our models likes this to get an existing user:

    $user = new User::find('damien_legrand'); // Same as new User::find('http://semreco/person/damien_legrand');

    $user->addLike('http://dbpedia.org/resource/Nine_Inch_Nails');

    return $user->firstname; // will return 'Damien'

Or to create a user :

    $user = new User();
    $user->firstname = "Damien";
    $user->lastname = "Legrand";
    $user->save(); // save the user in database

More to come

• Better documentation
• Created and Updated dates management
• Where conditions
• ...