added translations filter to filter by available base translations

core/Translate/Filter/ByBaseTranslations.php

+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @category Piwik
+ * @package Piwik
+ */
+
+namespace Piwik\Translate\Filter;
+
+use Piwik\Translate\Filter\FilterAbstract;
+
+/**
+ * @package Piwik
+ * @subpackage Piwik_Translate
+ */
+class ByBaseTranslations extends FilterAbstract
+{
+    /**
+     * Filter the given translations
+     *
+     * @param array $translations
+     *
+     * @return array   filtered translations
+     *
+     */
+    public function filter($translations)
+    {
+        $cleanedTranslations = array();
+
+        // filter out all translations that don't exist in english translations
+        foreach ($translations AS $pluginName => $pluginTranslations) {
+
+            if (empty($this->_baseTranslations[$pluginName])) {
+                $this->_filteredData[$pluginName] = $pluginTranslations;
+                continue;
+            }
+
+            foreach ($pluginTranslations as $key => $translation) {
+                if (isset($this->_baseTranslations[$pluginName][$key])) {
+                    $cleanedTranslations[$pluginName][$key] = $translation;
+                }
+            }
+
+            if (!empty($cleanedTranslations[$pluginName])) {
+                $diff = array_diff($translations[$pluginName], $cleanedTranslations[$pluginName]);
+            } else {
+                $diff = $translations[$pluginName];
+            }
+            if (!empty($diff)) $this->_filteredData[$pluginName] = $diff;
+        }
+
+        return $cleanedTranslations;
+    }
+}
\ No newline at end of file

tests/PHPUnit/Core/Translate/Filter/ByBaseTranslationsTest.php

+<?php
+use Piwik\Translate\Filter\ByBaseTranslations;
+
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+class ByBaseTranslationsTest extends PHPUnit_Framework_TestCase
+{
+    public function getFilterTestData()
+    {
+        return array(
+            // empty stays empty
+            array(
+                array(),
+                array(),
+                array(),
+                array()
+            ),
+            // empty plugin is removed
+            array(
+                array(
+                    'test' => array()
+                ),
+                array(),
+                array(),
+                array(
+                    'test' => array()
+                ),
+            ),
+            // empty values/plugins are removed
+            array(
+                array(
+                    'test' => array(
+                        'key' => 'value',
+                        'test' => 'test'
+                    )
+                ),
+                array(
+                    'test' => array(
+                        'key' => 'value',
+                        'x'   => 'y'
+                    )
+                ),
+                array(
+                    'test' => array(
+                        'key' => 'value',
+                    )
+                ),
+                array(
+                    'test' => array(
+                        'test' => 'test',
+                    )
+                ),
+            ),
+            // no change if no empty value
+            array(
+                array(
+                    'test' => array(
+                        'test' => 'test'
+                    )
+                ),
+                array(
+                    'test' => array(
+                        'test' => 'test'
+                    )
+                ),
+                array(
+                    'test' => array(
+                        'test' => 'test'
+                    )
+                ),
+                array()
+            ),
+            // empty values are removed, others stay
+            array(
+                array(
+                    'empty' => array(
+                        'test' => 'test'
+                    ),
+                    'test' => array(
+                        'test' => 'test',
+                        'empty' => '     ',
+                    )
+                ),
+                array(
+                    'empty' => array(
+                        'test' => 'test'
+                    ),
+                    'test' => array(
+                        'test' => 'test',
+                    )
+                ),
+                array(
+                    'empty' => array(
+                        'test' => 'test'
+                    ),
+                    'test' => array(
+                        'test' => 'test'
+                    )
+                ),
+                array(
+                    'test' => array(
+                        'empty' => '     ',
+                    )
+                )
+            ),
+        );
+    }
+
+    /**
+     * @dataProvider getFilterTestData
+     * @group Core
+     * @group Translate
+     */
+    public function testFilter($translations, $baseTranslations, $expected, $filteredData)
+    {
+        $filter = new ByBaseTranslations($baseTranslations);
+        $result = $filter->filter($translations);
+        $this->assertEquals($expected, $result);
+        $this->assertEquals($filteredData, $filter->getFilteredData());
+    }
+}