Upgrade ruleset.xml to PSR12 (#47)

Author: razvanphp

README.md

@@ -38,7 +38,7 @@ PHP_Codesniffer
 
 [PHP_CodeSniffer](https://github.com/squizlabs/PHP_CodeSniffer) coding standard, rule set
 and sniff token parsing classes for the [Yii 2 Web Framework](https://github.com/yiisoft/yii2/). Overally rules
-are based on PSR-2 standard with some minor exceptions and changes. Rules derived from PSR-2 standard and excluded
+are based on PSR-12 standard with some minor exceptions and changes. Rules derived from PSR-12 standard and excluded
 in Yii2 standard were implemented (or planned to be) as sniff classes.
 
 Rules could also be used for checking code style of an existing Yii2 applications.
@@ -54,6 +54,30 @@ After CodeSniffer is installed you can launch it with custom code style using th
 $ ./vendor/bin/phpcs --extensions=php --standard=Yii2 /home/resurtm/work/Yii2MegaApp/
 ```
 
+Installation can be also be done automatically with this tool:
+
+```bash
+composer require --dev dealerdirect/phpcodesniffer-composer-installer
+```
+
+When using Composer 2.2 or higher, Composer will [ask for your permission](https://blog.packagist.com/composer-2-2/#more-secure-plugin-execution) to allow this plugin to execute code. For this plugin to be functional, permission needs to be granted.
+
+When permission has been granted, the following snippet will automatically be added to your `composer.json` file by Composer:
+```json
+{
+    "config": {
+        "allow-plugins": {
+            "dealerdirect/phpcodesniffer-composer-installer": true
+        }
+    }
+}
+```
+
+When using Composer < 2.2, you can add the permission flag ahead of the upgrade to Composer 2.2, by running:
+```bash
+composer config allow-plugins.dealerdirect/phpcodesniffer-composer-installer true
+```
+
 If you're using PhpStorm you can configure it to use CodeSniffer using Settings → PHP → Code Sniffer.
 Yii2 code style can be specified at Inspections → PHP → PHP Code Sniffer validation.
 
@@ -66,7 +90,7 @@ Yii2 code style can be specified at Inspections → PHP → PHP Code Sniffer val
 PhpStorm
 --------
 
-Yii uses PSR-1 and PSR-2 as code style standards. You can choose these via `Settings` → `Code Style` → `PHP` → `Set from...` → `Predefined Style` → `PSR1/PSR2`.
+Yii uses PSR-12 as code style standard. You can choose these via `Settings` → `Code Style` → `PHP` → `Set from...` → `Predefined Style` → `PSR12`.
 
 ADDITIONAL NOTES
 ----------------

Yii2/ruleset.xml

@@ -2,7 +2,7 @@
 <ruleset name="Yii2">
     <description>Yii 2 Web Application Framework Coding Standard</description>
 
-    <rule ref="PSR2">
+    <rule ref="PSR12">
         <!-- Property names MUST start with an initial underscore if they are private. -->
         <exclude name="PSR2.Classes.PropertyDeclaration.Underscore"/>
 
@@ -18,6 +18,12 @@
         <exclude name="PSR2.ControlStructures.SwitchDeclaration"/>
     </rule>
 
+    <!-- display progress -->
+    <arg value="p"/>
+    <!-- Show error codes -->
+    <arg value="s"/>
+    <arg name="colors"/>
+
     <!-- Property declaration rules. -->
     <!-- TODO: -->