Form Validation – PHP Basics

Here, In this simple form validation  “Name”, “E-mail”, “Subject”, “Feedback” and “Gender” fields are required. These fields cannot be empty (error message is displayed if left empty). It must be filled out in the HTML form. For this validation, Variables – $nameErr, $emailErr, $subjectErr, $feedbackErr, $genderErr holds error message for fields which is empty. There’s if else statement for each $_POST variable to checks if $_POST variable is left empty (with PHP empty( ) function). Error Message is reserved in different error variables if it’s empty. & it sends the user input data through the test_input() function: if its not empty. And at last it displays all the inputs given by the user.

* when Fields are left Empty *

* user’s input displayed after submitting *

PHP Code :-

<?php
 // define variables and set to empty values
 $nameErr = $emailErr = $subjectErr = $genderErr = $websiteErr = $feedbackErr = "";
 $name = $email = $gender = $subject = $feedback = $website = "";

if ($_SERVER["REQUEST_METHOD"] == "POST") {
 if (empty($_POST["name"])) {
 $nameErr = "Name is required";
 } else {
 $name = test_input($_POST["name"]);
 }

if (empty($_POST["email"])) {
 $emailErr = "Email is required";
 } else {
 $email = test_input($_POST["email"]);
 }

if (empty($_POST["website"])) {
 $website = "";
 } else {
 $website = test_input($_POST["website"]);
 }

if (empty($_POST["subject"])) {
 $subjectErr = "Subject is required";
 } else {
 $subject = test_input($_POST["subject"]);
 }

if (empty($_POST["feedback"])) {
 $feedbackErr = "Feedback is required";
 } else {
 $feedback = test_input($_POST["feedback"]);
 }

if (empty($_POST["gender"])) {
 $genderErr = "Gender is required";
 } else {
 $gender = test_input($_POST["gender"]);
 }
 }

function test_input($data) {
 $data = trim($data);
 $data = stripslashes($data);
 $data = htmlspecialchars($data);
 return $data;
 }
 ?>

<h2>Simple Form Validation</h2>
 <h3>"Leave Your Feedbacks Here"</h3>
 <p><span class="error"> *Field Required*</span></p>
 <form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
 Name: <input type="text" name="name">
 <span class="error">* <?php echo $nameErr;?></span>
 <br><br>
 E-mail: <input type="text" name="email">
 <span class="error">* <?php echo $emailErr;?></span>
 <br><br>
 Website: <input type="text" name="website">
 <span class="error"><?php echo $websiteErr;?></span>
 <br><br>
 Subject: <input type="text" name="subject">
 <span class="error">*<?php echo $subjectErr;?></span>
 <br></br>
 Feedbacks: <textarea name="feedback" rows="4" cols="24"></textarea>
 <span class="error">*<?php echo $feedbackErr;?></span>
 <br><br>
 Gender:
 <input type="radio" name="gender" value="female">Female
 <input type="radio" name="gender" value="male">Male
 <input type="radio" name="gender" value="other">Other

<span class="error">* <?php echo $genderErr;?></span>
 <br><br>
 <input type="submit" name="submit" value="Submit">
 </form>

<?php
 echo "<h2>Your Input:</h2>";
 echo $name;
 echo "<br>";
 echo $email;
 echo "<br>";
 echo $website;
 echo "<br>";
 echo $subject;
 echo "<br>";
 echo $feedback;
 echo "<br>";
 echo $gender;
 ?>

</body>
 </html>