Support inclusion of configuration

This adds repeatable configuration property `skosmos:includeConfig` to
include configuration from file or URL. The configuration is cached as
usual, based on modification time of `config.ttl` only.

See #1403 for discussion.

Author: nichtich

model/GlobalConfig.php

@@ -78,7 +78,9 @@ private function initializeConfig()
                 $nskey = "namespaces of " . $key;
                 $this->graph = $this->cache->fetch($key);
                 $this->namespaces = $this->cache->fetch($nskey);
-                if ($this->graph === false || $this->namespaces === false) { // was not found in cache
+                if ($this->graph && $this->namespaces) { // found in cache
+                    $this->resource = $this->configResource($this->graph, "cache");
+                } else {
                     $this->parseConfig($this->filePath);
                     $this->cache->store($key, $this->graph);
                     $this->cache->store($nskey, $this->namespaces);
@@ -88,29 +90,80 @@ private function initializeConfig()
                 $this->parseConfig($this->filePath);
             }
 
-            $configResources = $this->graph->allOfType("skosmos:Configuration");
-            if (is_null($configResources) || !is_array($configResources) || count($configResources) !== 1) {
-                throw new Exception("config.ttl must have exactly one skosmos:Configuration");
-            }
-
-            $this->resource = $configResources[0];
             $this->initializeNamespaces();
         } catch (Exception $e) {
             echo "Error: " . $e->getMessage();
         }      
     }
 
+    /**
+     * Ensure there is exactely one skosmos:Configuration and return it.
+     */
+    private function configResource($graph, $source) {
+        $configResources = $graph->allOfType("skosmos:Configuration");
+        if (is_null($configResources) || !is_array($configResources) || count($configResources) !== 1) {
+            throw new Exception("$source must have exactly one skosmos:Configuration");
+        }
+        return $configResources[0];
+    }
+
+    /**
+     * Retrieves, parses and includes configuration in existing configuration.
+     * @param \EasyRdf\Resource URL or file of configuration in Turtle syntax.
+     */
+    private function includeConfig($location) {
+        $location = $location->getUri();
+
+        if (str_starts_with($location, "http://") || str_starts_with($location, "https://")) {
+            $ch = curl_init($location);
+            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+            curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-type: text/turtle'));
+            $turtle = curl_exec($ch);
+            $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+            if ($httpCode != 200 && $httpCode != 303) {
+                throw new Exception("Failed to include configuration from $location");
+            }
+            curl_close($ch);
+        } else {
+            if (file_exists($location)) {
+                $turtle = file_get_contents($location);
+            } else {
+                throw new Exception("Included config file $location does not exist!");
+            }
+        }
+
+        $parser = new SkosmosTurtleParser();
+        try {
+            $graph = $parser->parseGraph($turtle, $location);
+        } catch (Exception $e) {
+            throw new Exception("Failed to parse $location: " . $e->getMessage());
+        }
+
+        $configResource = $this->configResource($graph, $location);
+        foreach($graph->properties($configResource) as $property) {
+            foreach($configResource->all($property) as $value) {
+                $this->graph->add($this->resource, $property, $value);
+            }
+        }
+    }
+
     /**
      * Parses configuration from the config.ttl file
      * @param string $filename path to config.ttl file
      * @throws \EasyRdf\Exception
      */
     private function parseConfig($filename)
     {
-        $this->graph = new EasyRdf\Graph();
         $parser = new SkosmosTurtleParser();
-        $parser->parse($this->graph, file_get_contents($filename), 'turtle', $filename);
+        $this->graph = $parser->parseGraph(file_get_contents($filename), $filename);
         $this->namespaces = $parser->getNamespaces();
+
+        $this->resource = $this->configResource($this->graph, $filename);
+
+        $includes = $this->graph->allResources($this->resource, "skosmos:includeConfig");
+        foreach($includes as $location) {
+            $this->includeConfig($location);
+        }
     }
 
     /**

model/SkosmosTurtleParser.php

@@ -11,4 +11,14 @@ public function getNamespaces()
         return $this->namespaces;
     }
 
+    /**
+     * Parse Turtle into a new Graph and return it.
+     * @return EasyRdf\Graph
+     */
+    public function parseGraph($data, $baseUri)
+    {
+        $graph = new EasyRdf\Graph();
+        $this->parse($graph, $data, 'turtle', $baseUri);
+        return $graph;
+    }
 }

tests/GlobalConfigTest.php

@@ -116,6 +116,13 @@ public function testGetUiLanguageDropdown()
         $this->assertEquals(true, $this->config->getUiLanguageDropdown());
     }
 
+    public function testGetGlobalPlugins()
+    {
+        $this->assertEquals(["alpha", "Bravo", "charlie"], $this->config->getGlobalPlugins());
+    }
+
+    // included from testconfig-included.ttl
+
     public function testGetHoneypotEnabled()
     {
         $this->assertEquals(false, $this->config->getHoneypotEnabled());
@@ -126,17 +133,21 @@ public function testGetHoneypotTime()
         $this->assertEquals(2, $this->config->getHoneypotTime());
     }
 
-    public function testGetGlobalPlugins()
-    {
-        $this->assertEquals(["alpha", "Bravo", "charlie"], $this->config->getGlobalPlugins());
+    // --- test inclusion from URL
+
+    public function testInclusionFromURL() {
+        $conf = new GlobalConfig("/../tests/testconfig-include.ttl");
+        $this->assertEquals(2, $conf->getHoneypotTime());
     }
 
     // --- tests for the exception paths
 
     public function testInitializeConfigWithoutGraph()
     {
-        $this->expectOutputString('Error: config.ttl must have exactly one skosmos:Configuration');
-        $conf = new GlobalConfig('/../tests/testconfig-nograph.ttl');
+        $file = '/../tests/testconfig-nograph.ttl';
+        $filepath = realpath( dirname(__FILE__) . $file );
+        $this->expectOutputString("Error: $filepath must have exactly one skosmos:Configuration");
+        $conf = new GlobalConfig($file);
         $this->assertNotNull($conf);
     }
 

tests/init_fuseki.sh

@@ -33,5 +33,7 @@ for fn in ../test-vocab-data/*.ttl; do
     $(./bin/s-put http://localhost:13030/skosmos-test/data "http://www.skosmos.skos/$name/" "$fn")
 done
 
+$(./bin/s-put http://localhost:13030/skosmos-test/data "http://skosmos.config/" "../testconfig-included.ttl")
+
 cd ..
 

tests/testconfig-include.ttl

@@ -0,0 +1,8 @@
+@prefix skosmos: <http://purl.org/net/skosmos#> .
+@prefix : <http://base/#> .
+
+:config a skosmos:Configuration ;
+ 
+    # include configuration from from URL
+    skosmos:includeConfig <http://localhost:13030/skosmos-test/data?graph=http://skosmos.config/> .
+

tests/testconfig-included.ttl

@@ -0,0 +1,12 @@
+@prefix skosmos: <http://purl.org/net/skosmos#> .
+
+# This configuration is being included from file
+
+<http://example.org/> a skosmos:Configuration ;
+ 
+    # whether to enable the spam honey pot or not, enabled by default
+    skosmos:uiHoneypotEnabled false ;
+
+    # default time a user must wait before submitting a form
+    skosmos:uiHoneypotTime 2 .
+

tests/testconfig.ttl

@@ -59,12 +59,11 @@
     skosmos:feedbackEnvelopeSender "skosmos tests" ;
     # whether to display the ui language selection as a dropdown (useful for cases where there are more than 3 languages) 
     skosmos:uiLanguageDropdown true ;
-    # whether to enable the spam honey pot or not, enabled by default
-    skosmos:uiHoneypotEnabled false ;
-    # default time a user must wait before submitting a form
-    skosmos:uiHoneypotTime 2 ;
     # plugins to activate for the whole installation (including all vocabularies)
-    skosmos:globalPlugins ("alpha" "Bravo" "charlie") .
+    skosmos:globalPlugins ("alpha" "Bravo" "charlie") ;
+
+    # include another config file
+    skosmos:includeConfig <testconfig-included.ttl> .
 
 # Skosmos vocabularies