legrand/sparqlmodel

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

SPARQLModel for Laravel (PHP)

A model for Laravel 4, that can manage object through a graph database using SPARQL endpoint., _(*1)

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., _(*2)

Install

To install SPARQLModel in your Laravel 4 project, update your composer.json file by adding this line in the require array:, _(*3)

    "legrand/sparqlmodel": "dev-master"

After that you can open a terminal in the root folder of your project and run composer :, _(*4)

    composer update

it will add the package in your project., _(*5)

Configuration

This model need some configurations to work. Create a 'sparqlmodel.php' file in app/config and add this arry :, _(*6)

    <?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., _(*7)

Example

Now you can create a simple model. For example here a Like model :, _(*8)

    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, _(*9)

• $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 :, _(*10)

• 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 :, _(*11)

    <?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 :, _(*12)

• $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., _(*13)

Usage

Now we can use our models likes this to get an existing user:, _(*14)

    $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 :, _(*15)

    $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
• ...