/**
* The RDQL query operation operation executes a RDQL query against a model.
*
* @version $Id: rdql.php,v 1.8 2006/05/15 05:24:37 tgauss Exp $
* @author Phil Dawes <*****@*****.**>
*
* @package netapi
* @todo nothing
* @access public
*/
function rdql($model, $serializer)
{
if (isset($_REQUEST['closure'])) {
if (strtoupper($_REQUEST['closure']) == "TRUE") {
$closure = True;
} else {
$closure = False;
}
} else {
$closure = False;
}
$query = $_REQUEST["query"];
// php appears to escape quotes, so unescape them
$query = str_replace('\\"', '"', $query);
$query = str_replace("\\'", "'", $query);
// decode %xx
$query = rawurldecode($query);
/// debug
//var_dump($query);
$r = new RdqlParser();
$parsedq = $r->parseQuery($query);
addMissingSelectVarsToQuery($parsedq);
if (is_a($model, 'MemModel')) {
$eng = new RdqlMemEngine();
} else {
$eng = new RdqlDbEngine();
}
$rdqlres = $eng->queryModel($model, $parsedq, TRUE);
$rdqlIter = new RdqlResultIterator($rdqlres);
$outm = new MemModel();
while ($rdqlIter->hasNext()) {
$result = $rdqlIter->next();
generateResultStatementsFromVarResult($result, $parsedq, $outm, $closure, $model);
}
echo $serializer->Serialize($outm);
$outm->close();
}
/**
* Perform an RDQL query on this DbModel.
* This method returns an associative array of variable bindings.
* The values of the query variables can either be RAP's objects (instances of Node)
* if $returnNodes set to TRUE, or their string serialization.
*
* @access public
* @param string $queryString
* @param boolean $returnNodes
* @return array [][?VARNAME] = object Node (if $returnNodes = TRUE)
* OR array [][?VARNAME] = string
*
*/
function rdqlQuery($queryString, $returnNodes = TRUE)
{
require_once RDFAPI_INCLUDE_DIR . PACKAGE_RDQL;
$parser = new RdqlParser();
$parsedQuery =& $parser->parseQuery($queryString);
// this method can only query this DbModel
// if another model was specified in the from clause throw an error
if (isset($parsedQuery['sources'][0])) {
if ($parsedQuery['sources'][0] != $this->modelURI) {
$errmsg = RDFAPI_ERROR . '(class: DbModel; method: rdqlQuery):';
$errmsg .= ' this method can only query this DbModel';
trigger_error($errmsg, E_USER_ERROR);
}
}
$engine = new RdqlDbEngine();
$res =& $engine->queryModel($this, $parsedQuery, $returnNodes);
return $res;
}
/**
* Perform an RDQL query on this Model. Should work with all types of models.
* This method returns a MemModel containing the result statements.
* If $closure is set to TRUE, the result will additionally contain
* statements found by the findForward-method for blank nodes.
* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
* WARNING: If called with $closure = TRUE this method
* can be slow with large models.
* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
*
* @author Anton K�tlbacher <*****@*****.**>
* @author code snippets taken from the RAP Netapi by Phil Dawes and Chris Bizer
* @access public
* @param string $queryString
* @param boolean $closure
* @return object MemModel
*
*/
function &getMemModelByRDQL($queryString, $closure = FALSE)
{
require_once RDFAPI_INCLUDE_DIR . PACKAGE_RDQL;
$parser = new RdqlParser();
$parsedQuery =& $parser->parseQuery($queryString);
// If there are variables used in the pattern but not
// in the select clause, add them to the select clause
foreach ($parsedQuery['patterns'] as $n => $pattern) {
foreach ($pattern as $key => $val_1) {
if ($val_1['value'][0] == '?') {
if (!in_array($val_1['value'], $parsedQuery['selectVars'])) {
array_push($parsedQuery['selectVars'], $val_1['value']);
}
}
}
}
if (is_a($this, "DbModel")) {
$engine = new RdqlDbEngine();
$model = $this;
} elseif (is_a($this, "MemModel")) {
$engine = new RdqlMemEngine();
$model = $this;
} elseif (is_a($this, "ResModel")) {
$engine = new RdqlMemEngine();
$model = $this->model;
}
$res = $engine->queryModel($model, $parsedQuery, TRUE);
$rdqlIter = new RdqlResultIterator($res);
$newModel = new MemModel();
// Build statements from RdqlResultIterator
while ($rdqlIter->hasNext()) {
$result = $rdqlIter->next();
foreach ($parsedQuery['patterns'] as $n => $pattern) {
if (substr($pattern['subject']['value'], 0, 1) == '?') {
$subj = $result[$pattern['subject']['value']];
} else {
$subj = new Resource($pattern['subject']['value']);
}
if (substr($pattern['predicate']['value'], 0, 1) == '?') {
$pred = $result[$pattern['predicate']['value']];
} else {
$pred = new Resource($pattern['predicate']['value']);
}
if (substr($pattern['object']['value'], 0, 1) == '?') {
$obj = $result[$pattern['object']['value']];
} else {
if (isset($pattern['object']['is_literal'])) {
$obj = new Literal($pattern['object']['value']);
$obj->setDatatype($pattern['object']['l_dtype']);
$obj->setLanguage($pattern['object']['l_lang']);
} else {
$obj = new Resource($pattern['object']['value']);
}
}
$statement = new Statement($subj, $pred, $obj);
$newModel->add($statement);
// findForward() Statements containing an eventually given blank node
// and add them to the result, if closure = true
if (is_a($statement->object(), 'BlankNode') && $closure == True) {
$newModel = $model->findForward($statement->object(), NULL, NULL, $newModel);
}
if (is_a($statement->subject(), 'BlankNode') && $closure == True) {
$newModel = $model->findForward($statement->subject(), NULL, NULL, $newModel);
}
}
}
return $newModel;
}
</TR>
</TBODY>
</TABLE>
<P><INPUT name=submit type=submit value="submit me!">
</P></FORM><BR>
<?php
} else {
// Process the query if submitted
define("RDFAPI_INCLUDE_DIR", "./../api/");
include RDFAPI_INCLUDE_DIR . "RdfAPI.php";
include RDFAPI_INCLUDE_DIR . "rdql/RDQL.php";
echo "<center><a href='" . $HTTP_SERVER_VARS['PHP_SELF'] . "'>\n <h2>Go back to input form.</h2></a></center>";
if (isset($_POST['query_string'])) {
$queryString = stripslashes($_POST['query_string']);
// Parse the query
$parser = new RdqlParser();
$parsed =& $parser->parseQuery($queryString);
// If more than one source file provided show an error message
if (count($parsed['sources']) > 1) {
echo "<center><p class='rdql_comment'>We're sorry, but this Online Demo allows you to query only one document</p></center>";
}
// Create a new MemModel
$model = ModelFactory::getDefaultModel();
// Load and parse document
$model->load($parsed['sources'][0]);
// Process the query
$engine = new RdqlMemEngine();
$queryResult = $engine->queryModel($model, $parsed, TRUE);
// Show the query string
echo "<br><h3>Your query: </h3>";
echo "<table width='100%' bgcolor=#e7e7ef><tr><td>";
