rdfio/RDFIO

<?php

class SPARQLImport extends RDFIOSpecialPage {

    function __construct() {
        parent::__construct( 'SPARQLImport', 'rdfio-import' );
    }

    /**
     * The main code goes here
     * @param string $par (unused)
     */
    function execute( $par ) {
        unset( $par ); // Needed to suppress warning about unused variable which we include just for consistency.

        // Require rdfio-import permission for the current user
        if ( !$this->userCanExecute( $this->getUser() ) ) {
            throw new PermissionsError( 'rdfio-import', array( 'rdfio-specialpage-access-permission-missing' ) );
        }

        $wOut = $this->getOutput();
        $wRequest = $this->getRequest();
        $wUser = $this->getUser();

        $this->setHeaders();
        $submitButtonText = wfMessage( 'rdfio-start-import' )->parse();

        $offset = $wRequest->getVal( 'offset', 0 );
        $limit = $wRequest->getVal( 'limit', 25 );

        if ( $wRequest->getText( 'action' ) === 'import' ) {

            if ( !$this->allowInsert( $wUser, $wRequest ) ) {
                $this->errorMsg( wfMessage( 'rdfio-error-no-write-access' )->parse() );
                return;
            }

            $submitButtonText = wfMessage( 'rdfio-import-next-batch-of-triples' )->parse();
            $wOut->addHTML( $this->getHTMLForm( $submitButtonText, $limit, $offset + $limit ) );

            try {
                $importInfo = $this->import( $limit, $offset );
                $externalSparqlUrl = $importInfo['externalSparqlUrl'];
                $dataSourceImporter = new RDFIORDFImporter();
                $dataSourceImporter->addDataSource( $externalSparqlUrl, 'SPARQL' );
            } catch ( RDFIOException $e ) {
                $this->errorMsg( $e->getMessage() );
                return;
            }

            return;
        }

        $wOut->addHTML( $this->getHTMLForm( $submitButtonText, $limit, $offset ) );
        $wOut->addHTML( '<div id=sources style="display:none">' );
        $wOut->addWikiText( '{{#ask: [[Category:RDFIO Data Source]] [[RDFIO Import Type::SPARQL]] |format=list }}' );
        $wOut->addHTML( '</div>' );
    }

    function resourceType( $resourceStr ) {
        if ( substr( $resourceStr, 0, 4 ) === 'http' ) {
            return 'uri';
        }
        return 'literal';
    }

    protected function import( $limit = 25, $offset = 0 ) {
        $wOut = $this->getOutput();
        $wRequest = $this->getRequest();

        $externalSparqlUrl = $wRequest->getText( 'extsparqlurl' );

        if ( $externalSparqlUrl === '' ) {
            throw new RDFIOException( wfMessage( 'rdfio-error-empty-sparql-url' )->parse() );
        }

        if ( substr( $externalSparqlUrl, 0, 4 ) !== 'http' ) {
            throw new RDFIOException( wfMessage( 'rdfio-error-invalid-sparql-url' )->parse() );
        }

        $sparqlQuery = urlencode( "SELECT DISTINCT * WHERE { ?s ?p ?o } OFFSET $offset LIMIT $limit" );
        $sparqlQueryUrl = $externalSparqlUrl . '/' . '?query=' . $sparqlQuery;
        $sparqlResultXml = file_get_contents( $sparqlQueryUrl );

        $sparqlResultXmlObj = simplexml_load_string( $sparqlResultXml );

        $triples = array();

        if ( !is_object( $sparqlResultXmlObj ) ) {
            $this->errorMsg( wfMessage( 'rdfio-error-not-sparql-endpoint' )->parse() );
            return;
        }

        foreach ( $sparqlResultXmlObj->results->children() as $result ) {
            $triple = array();

            foreach ( $result as $binding ) {
                $str = $this->extractStringFromBinding( $binding );
                if ( $binding['name'] == 's' ) {
                    $triple['s'] = $str;
                    $triple['s_type'] = $this->resourceType( $triple['s'] );
                } else if ( $binding['name'] == 'p' ) {
                    $triple['p'] = $str;
                    $triple['p_type'] = $this->resourceType( $triple['p'] );
                } else if ( $binding['name'] == 'o' ) {
                    $triple['o'] = $str;
                    $triple['o_type'] = $this->resourceType( $triple['o'] );
                    $triple['o_datatype'] = '';
                }
            }

            $triples[] = $triple;
        }

        $rdfImporter = new RDFIORDFImporter();
        $rdfImporter->importTriples( $triples );
        $wOut->addHTML( $rdfImporter->showImportedTriples( $triples ) );

        return array( 'externalSparqlUrl' => $externalSparqlUrl );
    }

    protected function extractStringFromBinding( $binding ) {
        $str = (string)$binding->uri[0];
        if ( $str == '' ) {
            throw new Exception( 'Could not extract object from empty string (' . $binding->uri . '), in SPARQLImport' );
        }
        return $str;
    }

    protected function getHTMLForm( $buttonText, $limit, $offset ) {
        global $wgArticlePath;
        $wRequest = $this->getRequest();
        $wUser = $this->getUser();

        $thisPageUrl = str_replace( '/$1', '', $wgArticlePath ) . "/Special:SPARQLImport";
        $extSparqlUrl = $wRequest->getText( 'extsparqlurl', '' );

        $htmlForm = '
        <form method="post" action="" style="clear: none;">
                ' . wfMessage( 'rdfio-remote-sparql-endpoint-url' )->parse() . ':<br>
                <input type="hidden" name="action" value="import">
                <div id="urlfields">
                <input type="text" name="extsparqlurl" id="extsparqlurl" size="60" value="' . $extSparqlUrl . '"></input>
                <a href="#" onClick="addSources();">' . wfMessage( 'rdfio-use-previous-source' )->parse() . '</a>
                </div>
                <p><span style="font-style: italic; font-size: 11px">' . wfMessage( 'rdfio-example' )->parse() . ': http://www.semantic-systems-biology.org/biogateway/endpoint</span></p>
                <p>' . wfMessage( 'rdfio-batching-parameters-instructions' )->parse() . ':</p>
                <table style="margin-bottom: 1em;">
                    <tr>
                        <th style="text-align: right;">' . wfMessage( 'rdfio-limit' )->parse() . ':</th>
                        <td><input type="text" name="limit" size="3" value="' . $limit . '"></td>
                    </tr>
                    <tr>
                        <th style="text-align: right;">' . wfMessage( 'rdfio-offset' )->parse() . ':</th>
                        <td><input type="text" name="offset" size="3" value="' . $offset . '"></td>
                    </tr>
                </table>
                <input type="hidden" name="token" value="' . $wUser->getEditToken() . '">
                <input type="submit" value="' . $buttonText . '"> <a href="' . $thisPageUrl . '">' . wfMessage( 'rdfio-clear-form' ) . '</a></form>';
        $htmlForm .= $this->getJs();
        return $htmlForm;
    }

    public function getJs() {
        $jsCode = '<script type="text/javascript">
        function addSources() {
            var sourceList = document.getElementById("sources").getElementsByTagName("p")[0];
            var sources = sourceList.getElementsByTagName("a");
            var urlForm = document.getElementById("urlfields");
            var urlTextField = document.getElementById("extsparqlurl");
            var selectList = document.createElement("select");
            selectList.id = "sourceSelect";
            urlForm.appendChild(selectList);
            for (var i = 0; i < sources.length; i++) {
                var option = document.createElement("option");
                option.value = sources[i].innerHTML;
                option.text = sources[i].innerHTML;
                selectList.appendChild(option);
            }
            selectList.onchange = function() {selectedUrl = selectList.options[selectList.selectedIndex].value; selectedUrl1 = selectedUrl.substring(0,1).toLowerCase(); selectedUrl2 = selectedUrl.substring(1); selectedUrl = selectedUrl1.concat(selectedUrl2); urlTextField.value = selectedUrl};
        }
        </script>';
        return $jsCode;
    }

}