Differences

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--- programmieren:html:forms [2026/08/12 09:16] – type shi admin
+++ programmieren:html:forms [2026/09/03 14:56] (current) – Mistakes admin
@@ Line 1: / Line 1: @@
 ====== HTML Forms ======
+===== 1st Iteration =====
 HTML forms done like dis in a PHP app for example:
@@ Line 15: / Line 17: @@
 This leads to the textarea being below the submit button but still being part of the form since you can't put textareas as a form input.
-===== Reading data from Form =====
+==== Reading data from Form ====
 Form needs to do a Post then the data can be read from the post like so:
@@ Line 31: / Line 33: @@
 </code>
+===== 2nd Iteration =====
+Added
+<code php>
+htmlspecialchars()
+</code>
+around output so no special chars can be inserted.
+==== Flash Messages ====
+Yoooo I made flash messages, gotta put them in the session (cuz that stays across pages) then send the user back to the index and check in the index for flash messages.
+form.php
+<code php>
+foreach ($_POST as $key => $value) {
+    if (empty($value)) {
+        session_start();
+        $_SESSION['validation_error'] = $key . " cannot be empty";
+        header('Location: index.php');
+        exit;
+    }
+}
+</code>
+index.php
+<code php>
+<?php
+session_start();
+if (isset($_SESSION['validation_error'])): ?>
+    <div style="color: red">
+        <?= htmlspecialchars($_SESSION['validation_error']) ?>
+    </div>
+    <?php unset($_SESSION['validation_error']) ?>
+<?php endif ?>
+</code>
+The validation rules I made:
+<code php>
+if (strlen($post['name']) > 50) {
+    session_start();
+    $_SESSION['validation_error'] = "Name cannot be longer than 50 characters.";
+    header('Location: index.php');
+    exit;
+}
+if (!preg_match('/[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,4}$/', $post['email']) || strlen($post['email']) > 50) {
+    session_start();
+    $_SESSION['validation_error'] = "Email needs to be a valid email address and no longer than 50 characters.";
+    header('Location: index.php');
+    exit;
+}
+if (!preg_match(
+    '/^(\+?)(\d{2,4})(\s?)(-?)((\(0\))?)(\s?)(\d{2})(\s?)(-?)(\d{3})(\s?)(-?)(\d{2})(\s?)(-?)(\d{2})/',
+    $post['phone']
+)
+|| strlen($post['phone']) > 20) {
+    session_start();
+    $_SESSION['validation_error'] = "Phone needs to be a valid phone number.";
+    header('Location: index.php');
+    exit;
+}
+if (!date_parse_from_format('Y-m-d', $post['birthday']) || $post['birthday'] > date('Y-m-d')) {
+    session_start();
+    $_SESSION['validation_error'] = "Birthday needs to be a date in the format {yyyy-mm-dd} and cannot be in the future.";
+    header('Location: index.php');
+    exit;
+}
+if (strlen($post['message']) > 500) {
+    session_start();
+    $_SESSION['validation_error'] = "Message cannot be longer than 500 characters.";
+    header('Location: index.php');
+    exit;
+}
+</code>
+==== 3rd Iteration ====
+In the 3rd Iteration I simply added saving the data put into the form to the Database:
+<code php>
+    public function savePostData($post): void
+    {
+        $servername = "localhost";
+        $username = "root";
+        $password = "";
+        $dbname = "form_exercise";
+        $conn = new mysqli($servername, $username, $password, $dbname);
+        if ($conn->connect_error) {
+            die("Connection failed: " . $conn->connect_error);
+        }
+        $sql = "INSERT INTO entries (name, email, phone, birthday, message) VALUES (?, ?, ?, ?, ?)";
+        $stmt = $conn->prepare($sql);
+        if ($stmt) {
+            $stmt->bind_param("sssss", $name, $email, $phone, $birthday, $message);
+            $name = $post["name"];
+            $email = $post["email"];
+            $phone = $post["phone"];
+            $birthday = $post["birthday"];
+            $message = $post["message"];
+            $stmt->execute();
+        } else {
+            echo "Error: " . $sql . "<br>" . $conn->error;
+        }
+        $stmt->close();
+        $conn->close();
+    }
+</code>
+And displaying all entries in the index as a list:
+<code php>
+    public function displayAllEntries(): void
+    {
+        $servername = "localhost";
+        $username = "root";
+        $password = "";
+        $dbname = "form_exercise";
+        $conn = new mysqli($servername, $username, $password, $dbname);
+        if ($conn->connect_error) {
+            die("Connection failed: " . $conn->connect_error);
+        }
+        $sql = "SELECT * FROM entries";
+        $result = $conn->query($sql);
+        if ($result->num_rows > 0) {
+            while($row = $result->fetch_assoc()) {
+                echo 'Name: ' . htmlspecialchars($row['name']) . '  -  Email: ' . htmlspecialchars($row['email']) . '  -  Phone: ' . htmlspecialchars($row['phone']) . '  -  Birthday: ' . htmlspecialchars($row['birthday']) . '  -  Message: ' . htmlspecialchars($row['message']) . "<br>";
+            }
+        } else {
+            echo "0 results";
+        }
+    }
+</code>
+==== Mistakes ====
+Code style:
+  * Apperantly I had too much repetitive code
+  * Making it object oriented was good
+Functionality:
+  * Apperantly it was just barely reached, no explanation as to why.
+  * I couldve done better validation
+  * I couldve displayed multiple validation messages for all that was wrong
+  * I couldve used PHP native validation functions
+  * I couldve positioned the Form better
+Presenting:
+  * I was unprepared
+  * I didn't answer many questions
+  * There were some incidents with the streaming so that was bad blegh