Add a setting() function to the Functions API for more convenient management of site-specific runtime settings

wire/core/FunctionsAPI.php

@@ -430,3 +430,47 @@ function region($key = '', $value = null) {
 	return wireRegion($key, $value);
 }
 
+/**
+ * Get or set a runtime site setting
+ *
+ * This is a simple helper function for maintaining runtime settings in a site profile.
+ * It simply sets and gets settings that you define. It is preferable to using ProcessWire’s
+ * `$config` or `config()` API var/function because it is not used to store anything else for
+ * ProcessWire. It is also preferable to using a variable (or variables) because it is always
+ * in scope and accessible anywhere in your template files, even within existing functions.
+ *
+ * ~~~~~
+ * // set a setting named “foo” to value “bar”
+ * setting('foo', 'bar');
+ *
+ * // get a setting named “foo”
+ * $value = setting('foo');
+ *
+ * // set or replace multiple settings
+ * setting([
+ *   'foo' => 'value',
+ *   'bar' => 123,
+ *   'baz' => [ 'foo', 'bar', 'baz' ]
+ * ]);
+ *
+ * // get all settings in associative array
+ * $a = setting();
+ *
+ * // to unset a setting
+ * setting(false, 'foo');
+ * ~~~~~
+ *
+ * @param string|array $name Setting name, or array to set multiple
+ * @param string|int|array|float|mixed $value Value to set, or omit if getting value of $name (default=null)
+ * @return array|string|int|bool|mixed|null
+ *
+ */
+function setting($name = '', $value = null) {
+	static $settings = [];
+	if($name === '') return $settings;
+	if(is_array($name)) return $settings = array_merge($settings, $name);
+	if($name === false) { unset($settings[(string) $value]); return null; }
+	if($value !== null) $settings[$name] = $value;
+	return isset($settings[$name]) ? $settings[$name] : null;
+}
+