From 802a7f1b4107a2c5703e3721803bfbc5c3f459be Mon Sep 17 00:00:00 2001
From: Osma Suominen <osma.suominen@helsinki.fi>
Date: Tue, 19 Jan 2016 18:13:52 +0200
Subject: [PATCH] Obtain namespace prefixes from vocabularies.ttl and use them
 in RDF export. Fixes #387

---
 model/Model.php                         | 40 +++++++++++++++++++++----
 model/NamespaceExposingTurtleParser.php | 18 +++++++++++
 tests/ModelTest.php                     | 10 +++++++
 tests/testvocabularies.ttl              |  9 ++++++
 4 files changed, 72 insertions(+), 5 deletions(-)
 create mode 100644 model/NamespaceExposingTurtleParser.php

diff --git a/model/Model.php b/model/Model.php
index ea0dbb904..39acd52b6 100644
--- a/model/Model.php
+++ b/model/Model.php
@@ -23,6 +23,8 @@ class Model
 {
     /** EasyRdf_Graph graph instance */
     private $graph;
+    /** Namespaces from vocabularies configuration file */
+    private $namespaces;
     /** cache for Vocabulary objects */
     private $all_vocabularies = null;
     /** cache for Vocabulary objects */
@@ -40,6 +42,7 @@ public function __construct($config)
     {
         $this->global_config = $config;
         $this->initializeVocabularies();
+        $this->initializeNamespaces();
     }
 
     /**
@@ -63,21 +66,48 @@ private function initializeVocabularies()
             // use APC user cache to store parsed vocabularies.ttl configuration
             if (function_exists('apc_store') && function_exists('apc_fetch')) {
                 $key = realpath($this->getConfig()->getVocabularyConfigFile()) . ", " . filemtime($this->getConfig()->getVocabularyConfigFile());
+                $nskey = "namespaces of " . $key;
                 $this->graph = apc_fetch($key);
-                if ($this->graph === false) { // was not found in cache
-                    $this->graph = new EasyRdf_Graph();
-                    $this->graph->parse(file_get_contents($this->getConfig()->getVocabularyConfigFile()));
+                $this->namespaces = apc_fetch($nskey);
+                if ($this->graph === false || $this->namespaces === false) { // was not found in cache
+                    $this->parseVocabularies($this->getConfig()->getVocabularyConfigFile());
                     apc_store($key, $this->graph);
+                    apc_store($nskey, $this->namespaces);
                 }
             } else { // APC not available, parse on every request
-                $this->graph = new EasyRdf_Graph();
-                $this->graph->parse(file_get_contents($this->getConfig()->getVocabularyConfigFile()));
+                $this->parseVocabularies($this->getConfig()->getVocabularyConfigFile());
             }
         } catch (Exception $e) {
             echo "Error: " . $e->getMessage();
         }
     }
 
+    /**
+     * Parses vocabulary configuration and RDF namespaces from the vocabularies.ttl file
+     * @param string $filename path to vocabularies.ttl file
+     */
+
+    private function parseVocabularies($filename)
+    {
+        $this->graph = new EasyRdf_Graph();
+        $parser = new NamespaceExposingTurtleParser();
+        $parser->parse($this->graph, file_get_contents($filename), 'turtle', $filename);
+        $this->namespaces = $parser->getNamespaces();
+    }
+
+    /**
+     * Registers RDF namespaces from the vocabularies.ttl file for use by EasyRdf (e.g. serializing)
+     */
+    
+    private function initializeNamespaces() {
+        foreach ($this->namespaces as $prefix => $full_uri) {
+            if ($prefix != '' && EasyRdf_Namespace::get($prefix) === null) // if not already defined
+            {
+                EasyRdf_Namespace::set($prefix, $full_uri);
+            }
+        }
+    }
+
     /**
      * Return the version of this Skosmos installation, or "unknown" if
      * it cannot be determined. The version information is based on Git tags.
diff --git a/model/NamespaceExposingTurtleParser.php b/model/NamespaceExposingTurtleParser.php
new file mode 100644
index 000000000..d24e7e111
--- /dev/null
+++ b/model/NamespaceExposingTurtleParser.php
@@ -0,0 +1,18 @@
+<?php
+/**
+ * Copyright (c) 2016 University of Helsinki
+ * MIT License
+ * see LICENSE.txt for more information
+ */
+
+class NamespaceExposingTurtleParser extends EasyRdf_Parser_Turtle
+{
+    /**
+     * Returns the namespace prefixes as an array of prefix => URI
+     * @return array $namespaces
+     */
+    public function getNamespaces()
+    {
+        return $this->namespaces;
+    }
+}
diff --git a/tests/ModelTest.php b/tests/ModelTest.php
index 2bd82f572..1932a545c 100644
--- a/tests/ModelTest.php
+++ b/tests/ModelTest.php
@@ -263,6 +263,16 @@ public function testSearchConceptsAndInfoWithOneVocabCaseInsensitivity() {
     $this->assertEquals('http://www.skosmos.skos/test/ta116', $result['results'][0]->getUri());
     $this->assertEquals(1, $result['count']);
   }
+  
+  /**
+   * Test for issue #387: make sure namespaces defined in vocabularies.ttl are used for RDF export
+   * @covers Model::getRDF
+   */
+   
+  public function testGetRdfCustomPrefix() {
+    $result = $this->model->getRDF('prefix', 'http://www.skosmos.skos/prefix/p1', 'text/turtle');
+    $this->assertContains("@prefix my: <http://example.com/myns#> .", $result);
+  }
 
   /**
    * @covers Model::getRDF
diff --git a/tests/testvocabularies.ttl b/tests/testvocabularies.ttl
index f8ad299b1..5b04fdbd2 100644
--- a/tests/testvocabularies.ttl
+++ b/tests/testvocabularies.ttl
@@ -12,6 +12,7 @@
 @prefix skosmos: <http://purl.org/net/skosmos#> .
 @prefix isothes: <http://purl.org/iso25964/skos-thes#>.
 @prefix meta: <http://www.skosmos.skos/test-meta/> .
+@prefix my: <http://example.com/myns#> .
 @prefix : <#> .
 
 
@@ -102,6 +103,14 @@
 	skosmos:language "en";
 	skosmos:sparqlGraph <http://www.skosmos.skos/changes/> .
 
+:prefix a skosmos:Vocabulary, void:Dataset ;
+	dc11:title "A vocabulary for testing custom prefixes"@en ;
+	dc:subject :cat_general ;
+	void:uriSpace "http://www.skosmos.skos/prefix/";
+	void:sparqlEndpoint <http://localhost:3030/ds/sparql> ;
+	skosmos:language "en";
+	skosmos:sparqlGraph <http://www.skosmos.skos/prefix/> .
+
 <http://skosmos.skos/dump/test/groups> dc:format "application/rdf+xml" .
 
 :cat_science a skos:Concept ;