add piwik installation

www/analytics/core/Settings/StorageInterface.php

@@ -0,0 +1,52 @@
+<?php
+/**
+ * Created by PhpStorm.
+ * User: thomassteur
+ * Date: 25.10.13
+ * Time: 13:33
+ */
+namespace Piwik\Settings;
+
+/**
+ * Base type of all Setting storage implementations.
+ */
+interface StorageInterface
+{
+    /**
+     * Gets the current value for this setting. If no value is specified, the default value will be returned.
+     *
+     * @param Setting $setting
+     *
+     * @return mixed
+     *
+     * @throws \Exception In case the setting does not exist or if the current user is not allowed to change the value
+     *                    of this setting.
+     */
+    public function getSettingValue(Setting $setting);
+
+    /**
+     * Removes the value for the given setting. Make sure to call `save()` afterwards, otherwise the removal has no
+     * effect.
+     *
+     * @param Setting $setting
+     */
+    public function removeSettingValue(Setting $setting);
+
+    /**
+     * Sets (overwrites) the value for the given setting. Make sure to call `save()` afterwards, otherwise the change
+     * has no effect. Before the value is saved a possibly define `validate` closure and `filter` closure will be
+     * called. Alternatively the value will be casted to the specfied setting type.
+     *
+     * @param Setting $setting
+     * @param string $value
+     *
+     * @throws \Exception In case the setting does not exist or if the current user is not allowed to change the value
+     *                    of this setting.
+     */
+    public function setSettingValue(Setting $setting, $value);
+
+    /**
+     * Saves (persists) the current setting values in the database.
+     */
+    public function save();
+}