commit existing workshops

workshop5/calculator.php

@@ -0,0 +1,18 @@
+<?php
+
+$view = new stdClass();
+$view->pageTitle = 'Calculator';
+require_once('Models/Calculator.php');
+
+if(isset($_POST['submit'])) {
+    $calculator = new Calculator($_POST['expression']);
+    $value = $calculator->calculate();
+    if (!$value) {
+        $view->value = "Invalid Number";
+    }
+    else {
+        $view->result = 'The result is ' . $value;
+    }
+}
+
+require_once('Views/calculator.phtml');