Validate coverage

Creates a Validator class to help validate various elements. Currently
just a static class that better validates WKT geometry types

fixes #314 and #288

helpers/Coverage.php

@@ -19,11 +19,13 @@ function nl_extractWkt($coverage) {
     $wkt = null;
 
     // Get coverage format.
-    $format = geoPHP::detectFormat($coverage);
+    if (Validator::isValidWkt($coverage)) {
+        $format = geoPHP::detectFormat($coverage);
 
-    // Convert / reduce to WKT.
-    if (in_array($format, array('wkt', 'kml'))) {
-        $wkt = geoPHP::load($coverage)->out('wkt');
+        // Convert / reduce to WKT.
+        if (in_array($format, array('wkt', 'kml'))) {
+            $wkt = geoPHP::load($coverage)->out('wkt');
+        }
     }
 
     return $wkt;

helpers/Validators.php

@@ -0,0 +1,29 @@
+<?php
+
+/**
+ * Helper classes for validations
+ *
+ * @category   Utilities
+ * @package    Omeka
+ * @subpackage Neatline
+ * @author     Scholars' Lab <scholarslab@virginia.edu>
+ * @copyright  2014 Rector and Board of Visitors, University of Virginia
+ * @license    http://www.apache.org/licenses/LICENSE-2.0.html Apache 2
+ */
+class Validator
+{
+    /**
+     * Tests if a given string contains valid WKT
+     *
+     * @param string $coverage Coverage string to test
+     *
+     * @return boolean if the string is found
+     */
+    static function isValidWkt($coverage)
+    {
+        return (bool) preg_match(
+            '#(point|linestring|polygon|multipoint|multilinestring|multipolygon|geometrycollection)#',
+            strtolower($coverage)
+        );
+    }
+}

plugin.php

@@ -43,6 +43,7 @@
 require_once NL_DIR.'/helpers/Schemas.php';
 require_once NL_DIR.'/helpers/Strings.php';
 require_once NL_DIR.'/helpers/Styles.php';
+require_once NL_DIR.'/helpers/Validators.php';
 require_once NL_DIR.'/helpers/Views.php';
 
 // Vendor:

tests/phpunit/tests/unit/Helpers/CoverageTest.php

@@ -0,0 +1,24 @@
+<?php
+
+/**
+ * @package     omeka
+ * @subpackage  neatline
+ * @copyright   2014 Rector and Board of Visitors, University of Virginia
+ * @license     http://www.apache.org/licenses/LICENSE-2.0.html
+ */
+
+class HelpersTest_Coverage extends Neatline_Case_Default
+{
+    /**
+     * `nl_explode` should split on ','.
+     */
+    public function testExtractValueWKT()
+    {
+        $this->assertNotNull(nl_extractWkt('POINT (13 42)'));
+    }
+
+    public function testIgnoreNonWKT()
+    {
+        $this->assertNull(nl_extractWkt('Paris'));
+    }
+}