1 <?php

     2 namespace CorpusParole\Libraries\Sparql;

     3 

     4 use EasyRdf\Graph;

     5 use CorpusParole\Libraries\CorpusParoleException;

     6 use Config;

     7 use Log;

     8 

     9 /**

    10  *

    11  */

    12 class SparqlClient {

    13 

    14     private $currentTransactionUrl = null;

    15 

    16     function __construct($httpClient, $sparqlClient) {

    17         $this->sparqlClient = $sparqlClient;

    18         $this->httpClient = $httpClient;

    19     }

    20 

    21     private function getHttpClient() {

    22         return $this->httpClient;

    23     }

    24 

    25     public function getCurrentTransactionUrl() {

    26         return $this->currentTransactionUrl;

    27     }

    28 

    29     /**

    30      * Start transaction.

    31      * @return boolean true if a transaction was started, false otherwise

    32      * @throws CorpusParoleException if the  transaction could not be stared

    33      */

    34     public function startTransaction() {

    35         if(!is_null($this->currentTransactionUrl)) {

    36             // We just continue the current transaction

    37             return false;

    38         }

    39         //Log::debug('http_client base uri: ' . $this->getHttpClient()->getConfig('base_uri'));

    40         $sesameRepository = config('corpusparole.sesame_repository');

    41         $resp = $this->getHttpClient()->post("$sesameRepository/transactions");

    42         //$resp = $this->getHttpClient()->post('transactions');

    43         //TODO check errors

    44         if($resp->getStatusCode() != 201) {

    45             throw new CorpusParoleException("Error when starting transaction : "

    46                 . $resp->getStatusCode() . " - "

    47                 . $resp->getReasonPhrase() . " : " . $resp->getBody(), 1);

    48         }

    49 

    50         $this->currentTransactionUrl = $resp->getHeader('Location')[0];

    51 

    52         return true;

    53     }

    54 

    55     /**

    56      * Rollback transaction.

    57      * @return boolean true if a transaction was started, false otherwise

    58      * @throws CorpusParoleException if the  transaction could not be rollbacked

    59      */

    60     public function rollback() {

    61         if(is_null($this->currentTransactionUrl)) {

    62             // We just continue the current transaction

    63             return false;

    64         }

    65         $resp = $this->getHttpClient()->delete($this->currentTransactionUrl);

    66 

    67         if($resp->getStatusCode() != 204) {

    68             throw new CorpusParoleException("Could not cancel transaction : "

    69                 . $resp->getStatusCode() . " - "

    70                 . $resp->getReasonPhrase() . " : " . $resp->getBody(), 1);

    71         }

    72         $this->currentTransactionUrl = null;

    73 

    74         return true;

    75     }

    76 

    77     /**

    78      * Commit transaction.

    79      * @return boolean true if a transaction was started, false otherwise

    80      * @throws CorpusParoleException if the  transaction could not be commited

    81      */

    82     public function commit() {

    83         if(is_null($this->currentTransactionUrl)) {

    84             // We just continue the current transaction

    85             return false;

    86         }

    87         $resp = $this->getHttpClient()->put($this->currentTransactionUrl, ['query' => ['action' => 'COMMIT']]);

    88         if($resp->getStatusCode() != 200) {

    89             throw new CorpusParoleException("Could not commit transaction : "

    90                 . $resp->getStatusCode() . " - "

    91                 . $resp->getReasonPhrase() . " : " . $resp->getBody(), 1);

    92         }

    93         $this->currentTransactionUrl = null;

    94         return true;

    95     }

    96 

    97     protected function updateData($operation, Graph $graph)

    98     {

    99         $graphUri = $graph->getUri();

   100         $query = "$operation DATA {";

   101         if ($graphUri) {

   102             $query .= "GRAPH <$graphUri> {";

   103         }

   104         $query .= $graph->serialise('ntriples');

   105         if ($graphUri) {

   106             $query .= "}";

   107         }

   108         $query .= '}';

   109 

   110         $resp = $this->getHttpClient()->put(

   111             $this->currentTransactionUrl, [

   112                 'query' => ['action' => 'UPDATE'],

   113                 'form_params'=> ['update' => $query],

   114             ]

   115         );

   116         if($resp->getStatusCode() != 204) {

   117             throw new CorpusParoleException("Could not update in transaction with operation $operation: "

   118                 . $resp->getStatusCode() . " - "

   119                 . $resp->getReasonPhrase() . " : " . $resp->getBody(), 1);

   120         }

   121     }

   122 

   123     public function add(Graph $graph) {

   124         $this->updateData('INSERT', $graph);

   125     }

   126 

   127     public function delete(Graph $graph) {

   128         $this->updateData('DELETE', $graph);

   129     }

   130 

   131     /** Make a query to the SPARQL endpoint

   132      *

   133      * Just call and return EasyRdf\Sparql\Client::query

   134      *

   135      * @param string $query The query string to be executed

   136      * @return object EasyRdf\Sparql\Result|EasyRdf\Graph Result of the query.

   137      */

   138     public function query($query) {

   139         return $this->sparqlClient->query($query);

   140     }

   141 

   142 }