update readme, add __callStatic func

Author: Igor Chepurnoy

README.md

@@ -39,6 +39,10 @@ to the require section of your `composer.json` file.
 ## Declaration
 
 ```php
+<?php
+
+namespace app\models\enums;
+
 use yii2mod\enum\helpers\BaseEnum;
 
 class PostStatus extends BaseEnum
@@ -66,7 +70,16 @@ class PostStatus extends BaseEnum
     ];
 }
 ```
-## Usage
+## Enum creation
+```php
+$status = new PostStatus(PostStatus::PENDING);
+
+// or you can use the magic methods
+
+$status = PostStatus::PENDING();
+```
+
+## Static methods
 ```php
 PostStatus::getConstantsByValue() // ['PENDING', 'APPROVED', 'REJECTED', 'POSTPONED']
 PostStatus::getConstantsByName() // ['PENDING' => 0, 'APPROVED' => 1, 'REJECTED' => 2, 'POSTPONED' => 3]
@@ -78,3 +91,35 @@ PostStatus::listData() // ['Pending', 'Approved', 'Rejected', 'Postponed']
 PostStatus::getLabel(1) // Approved
 PostStatus::getValueByName('Approved') // 1
 ```
+## Type-Hint and Validation Rules
+```php
+<?php
+
+use models\enums\PostStatus;
+use yii\db\ActiveRecord;
+
+class CommentModel extends ActiveRecord
+{
+    public function rules()
+    {
+        return [
+            ['status', 'default', 'value' => PostStatus::APPROVED],
+            ['status', 'in', 'range' => PostStatus::getConstantsByName()],
+        ];
+    }
+
+    public function setStatus(PostStatus $status)
+    {
+        $this->status = $status;
+    }
+
+    public function getStatus()
+    {
+        if (!$this->status) {
+            $this->status = PostStatus::PENDING();
+        }
+        return $this->status;
+    }
+}
+```
+

helpers/BaseEnum.php

@@ -2,6 +2,7 @@
 
 namespace yii2mod\enum\helpers;
 
+use BadMethodCallException;
 use ReflectionClass;
 use UnexpectedValueException;
 use Yii;
@@ -265,4 +266,33 @@ public static function isValidValue($value)
 
         return array_key_exists($value, $constants);
     }
+
+    /**
+     * Returns a value when called statically like so: MyEnum::SOME_VALUE() given SOME_VALUE is a class constant
+     *
+     * @param string $name
+     * @param array $arguments
+     *
+     * @return static
+     *
+     * @throws BadMethodCallException
+     */
+    public static function __callStatic($name, $arguments)
+    {
+        $constants = static::getConstantsByName();
+
+        if (isset($constants[$name])) {
+            return new static($constants[$name]);
+        }
+
+        throw new BadMethodCallException("No static method or enum constant '$name' in class " . get_called_class());
+    }
+
+    /**
+     * @return string
+     */
+    public function __toString()
+    {
+        return (string)$this->_value;
+    }
 }

tests/EnumTest.php

@@ -52,6 +52,14 @@ public function testCreateByValue()
         $this->assertTrue(array_key_exists($enum->getName(), PostStatus::getConstantsByName()));
     }
 
+    public function testCreateByStaticFunction()
+    {
+        $enum = PostStatus::APPROVED();
+
+        $this->assertEquals(PostStatus::APPROVED, $enum->getValue());
+        $this->assertTrue(array_key_exists($enum->getName(), PostStatus::getConstantsByName()));
+    }
+
     /**
      * @expectedException \UnexpectedValueException
      */