[Rdfapi-php-svn] SF.net SVN: rdfapi-php: [546] trunk/rdfapi-php/api/sparql/SparqlEngineDb/ ResultRenderer/JSON.php

[<fu...@us...>]

Revision: 546
          http://rdfapi-php.svn.sourceforge.net/rdfapi-php/?rev=546&view=rev
Author:   fusel2k
Date:     2007-11-06 06:26:06 -0800 (Tue, 06 Nov 2007)

Log Message:
-----------
[create] JSON result renderer roughly following http://www.w3.org/2001/sw/DataAccess/json-sparql/

Added Paths:
-----------
    trunk/rdfapi-php/api/sparql/SparqlEngineDb/ResultRenderer/JSON.php

Added: trunk/rdfapi-php/api/sparql/SparqlEngineDb/ResultRenderer/JSON.php
===================================================================
--- trunk/rdfapi-php/api/sparql/SparqlEngineDb/ResultRenderer/JSON.php	                        (rev 0)
+++ trunk/rdfapi-php/api/sparql/SparqlEngineDb/ResultRenderer/JSON.php	2007-11-06 14:26:06 UTC (rev 546)
@@ -0,0 +1,154 @@
+<?php
+require_once RDFAPI_INCLUDE_DIR . 'sparql/SparqlEngineDb/ResultRenderer.php';
+
+/**
+*   Sparql DB JSON Renderer. Roughly follows http://www.w3.org/2001/sw/DataAccess/json-sparql/;
+*
+*   @author Christoph Rie\xDF
+*   @license http://www.gnu.org/licenses/lgpl.html LGPL
+*
+*   @package sparql
+*/
+class SparqlEngineDb_ResultRenderer_JSON implements SparqlEngineDb_ResultRenderer
+{
+
+    /**
+    *   Converts the database results into JSON Format
+    *
+    *   @param array $arRecordSets  Array of (possibly several) SQL query results.
+    *   @param Query $query     SPARQL query object
+    *   @param SparqlEngineDb $engine   Sparql Engine to query the database
+    *   @return mixed   HTML code
+    */
+    public function convertFromDbResults($arRecordSets, Query $query, SparqlEngineDb $engine) {
+    	
+        $this->query = $query;
+        $this->sg    = $engine->getSqlGenerator();
+        $strResultForm = $query->getResultForm();
+        switch ($strResultForm) {
+            case 'select':
+            case 'select distinct':
+                $results = $this->createFromRecords($arRecordSets, $strResultForm);
+				$strCode = json_encode(array('head' => array('vars'=>$this->getResultVars()),'results'=>array('bindings'=>$results)));
+				//$strCode = str_replace(',{',','.PHP_EOL.'{',$strCode);
+                break;
+			case 'construct':
+            case 'describe':
+                throw new Exception(
+                    'Construct and describe are not supported by the'
+                    . ' JSON renderer'
+                );
+
+            case 'count':
+            case 'ask':
+                if (count($arRecordSets) > 1) {
+                    throw new Exception(
+                        'More than one result set for a '
+                        . $strResultForm . ' query not supported by JSON Renderer'
+                    );
+                }
+
+                $nCount = 0;
+                $dbRecordSet = reset($arRecordSets);
+                foreach ($dbRecordSet as $row) {
+                    $nCount += intval($row['count']);
+                    break;
+                }
+
+                if ($strResultForm == 'ask') {
+                    $strcode = json_encode(array('boolean' => ($nCount > 0)));
+                } else {
+                    $strcode = json_encode(array('int' => $nCount ));
+                }
+                break;
+            default:
+            	throw new Exception('Error');
+        }
+        
+        return $strCode;
+        
+
+    }
+    /**
+     * Method to create from record with specific resultform (not used yet)
+     *
+     * @param array $arRecordSets  Array of (possibly several) SQL query results.
+     * @param unknown_type $strResultForm
+     * @return array ready for json conversion
+     */
+	protected function createFromRecords($arRecordSets, $strResultForm) {
+		
+		$arVarAssignments = $this->sg->arVarAssignments;
+		$code = '';
+		$arResultVars = $this ->getResultVars();
+		$results = array();
+		foreach ($arRecordSets[0] as $value) {
+			$node = array();
+			foreach ($arResultVars as $ResultVar) {
+				$nodeType = $value[$arVarAssignments[$ResultVar][0].'.'.$arVarAssignments[$ResultVar]['sql_is']];
+				if ($type == 'r' || $type === null ) {
+					$node[$ResultVar] = array('type'=> 'uri','value'=>$value[$arVarAssignments[$ResultVar][0].'.'.$arVarAssignments[$ResultVar]['sql_value']]);
+					
+				}
+				
+				if ($value[$arVarAssignments[$ResultVar][0].'.'.$arVarAssignments[$ResultVar]['sql_is']] == 'l') {
+					$literalType = $value[$arVarAssignments[$ResultVar][0].'.'.$arVarAssignments[$ResultVar]['sql_type']];
+					$literalLang = $value[$arVarAssignments[$ResultVar][0].'.'.$arVarAssignments[$ResultVar]['sql_lang']];
+					$literalValue = $value[$arVarAssignments[$ResultVar][0].'.'.$arVarAssignments[$ResultVar]['sql_value']];
+					$node[$ResultVar] = $this->getLiteral($literalValue,$literalLang,$literalType);
+				}
+			}
+			$results[]=$node;
+			
+			
+		}
+		return $results;
+
+	}
+	
+	/**
+	 * COnverting Literals to array ready for json
+	 *
+	 * @param unknown_type $value
+	 * @param unknown_type $lang
+	 * @param unknown_type $type
+	 * @return unknown
+	 */
+	private function getLiteral($value, $lang , $type) {
+		
+		$ret = array();
+		
+		$type = 'literal';
+		
+		if ($value != 'literal') {
+			$ret['value'] = $value;
+		}
+		
+		if ($lang != '') {
+			$ret['lang'] = $lang;
+		}
+		
+		if ($type != '') {
+			$ret['type'] = $type; 
+		}
+		
+		return $ret;
+	}
+	
+	/**
+	 * Giving array of used Vars also resolves the all-quantifier *
+	 *
+	 * @return array of vars as strings
+	 */
+	protected function getResultVars() {
+		$arResultVars = $this->query->getResultVars();
+		if (in_array('*', $arResultVars)) {
+			$arResultVars   = array_keys($this->sg->arVarAssignments);
+		}
+		
+		return $arResultVars;
+	}
+
+}
+
+?>
\ No newline at end of file


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