[PHP] [StepStrategy] Replace type code constant by abstract function making it mandatory to define codes for each type

Author: JavierCane

examples/php/php-step_strategy-01_base/src/ExerciseStepType.php

@@ -12,4 +12,9 @@ public function estimatedCompletionMinutes(): int
     {
         return self::EXERCISE_STEP_DURATION_ESTIMATION_IN_MINUTES;
     }
+
+    protected static function code(): int
+    {
+        return 2;
+    }
 }

examples/php/php-step_strategy-01_base/src/QuizStepType.php

@@ -19,4 +19,9 @@ public function estimatedCompletionMinutes(): int
     {
         return self::QUIZ_STEP_QUESTION_DURATION_ESTIMATION_IN_MINUTES * count($this->quizQuestions);
     }
+
+    protected static function code(): int
+    {
+        return 1;
+    }
 }

examples/php/php-step_strategy-01_base/src/StepType.php

@@ -8,23 +8,21 @@
 
 abstract class StepType
 {
-    private const VIDEO_STEP_TYPE = 0;
-    private const QUIZ_STEP_TYPE = 1;
-    private const EXERCISE_STEP_TYPE = 2;
-
     public static function fromPrimitive(int $code, ?int $videoDurationInMinutes, ?array $quizQuestions)
     {
         switch ($code) {
-            case self::VIDEO_STEP_TYPE:
+            case VideoStepType::code():
                 return new VideoStepType($videoDurationInMinutes);
-            case self::QUIZ_STEP_TYPE:
+            case QuizStepType::code():
                 return new QuizStepType($quizQuestions);
-            case self::EXERCISE_STEP_TYPE:
+            case ExerciseStepType::code():
                 return new ExerciseStepType();
             default:
                 throw new InvalidArgumentException("Unrecognized Step type code");
         }
     }
 
+    abstract protected static function code(): int;
+
     abstract public function estimatedCompletionMinutes(): int;
 }

examples/php/php-step_strategy-01_base/src/VideoStepType.php

@@ -17,4 +17,9 @@ public function estimatedCompletionMinutes(): int
     {
         return $this->videoDurationInMinutes;
     }
+
+    protected static function code(): int
+    {
+        return 0;
+    }
 }