Producing error messages in php validation - php

Question

I am trying to validate a form using php, the code i have doesn't prevent the form from being submitted when the inputs are invalid, however, the error messages that i would like them displayed do not show on the form, the form is returned empty of error messages even tho i have them echo'ed inside the form. could you help me display the error messages upon unsuccessful submission of the form ? i added my form code and the php code. both are seperate files , the action in the form leads to the php validation code like so (action = "report_form_php.php).
<form method="post" onsubmit=" return formSubmit()" action="report_form_php.php">
<div class="error1" id= "errorMsg">* Required Fields</div>
<div class="error" id= "errorMsg1">*<?php echo $staffErr; ?></div>
<div>
<label for="staff_name"><b>Staff Name:</b></label>
<input class="field" id="staff_name" name="staffname" onclick=" return staffValidation()" onchange=" return staffValidation()" id="subject" type="text" placeholder="Staff Name" >
</div><br>
<div class="error" id= "errorMsg2">*<?php echo $emailErr; ?></div>
<div>
<label for="email"><b>Email:</b></label>
<input class="field" id="email1" name="email" onclick=" return emailValidation()" onchange=" return emailValidation()" type="email" placeholder="staff#wearview.com" >
</div><br>
<div class="error" id= "errorMsg3">*<?php echo $subjectErr; ?></div>
<div>
<label for="subject"><b>Subject:</b></label>
<input class="field" name="subject" id="subject1" onclick=" return subjectValidation()" onchange=" return subjectValidation()" type="text" placeholder="Subject Title" >
</div><br>
<div class="error" id= "errorMsg4">*<?php echo $problemErr; ?></div>
<div>
<select onclick=" return problemValidation()" onchange=" return problemValidation()" class="field4" name="problem_type" id="problemtypes">
<option value="">Problem Type</option>
<option value="Hardware">Hardware</option>
<option value="Software">Software</option>
<option value="Software&Hardware">Software & Hardware</option>
<option value="Other">Other</option>
</select>
</div><br>
<div class="error" id= "errorMsg5">*<?php echo $descriptionErr; ?></div>
<div>
<textarea class="field2" id="description1" name="description" onclick=" return descriptionValidation()" onchange=" return descriptionValidation()" placeholder="Description goes here" rows="15" cols="90"></textarea>
</div>
<div>
<button class="field3" type="submit" class="btn">Submit</button>
<input type="checkbox" id="notify" name="notify" value="">
<label for="notify">Inform me by email when issue is resolved.</label>
</div>
</form>
<?php
// define variables and set to empty values
$staffErr = $emailErr = $subjectErr = $problemErr = $descriptionErr= "";
$staffname = $email = $subject = $problem_type = $description = "";
// staff name validation:
if ($_SERVER["REQUEST_METHOD"] == "POST") {
if (empty($_POST["staffname"])) {
$staffErr = "Staff Name is required";
} else {
$staff_name = test_input($_POST["staffname"]);
// check if name only contains letters and whitespace
if (!preg_match("/^[a-zA-Z-' ]*$/",$staffname)) {
$staffErr = "Only letters and white space allowed";
}
}
// email validation:
if (empty($_POST["email"])) {
$emailErr = "Email is required";
} else {
$email = test_input($_POST["email"]);
// check if e-mail address is well-formed
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
$emailErr = "Please enter a valid email.";
}
}
// subject validation:
if (empty($_POST["subject"])) {
$subjectErr = "Subject is required";
} else {
$subject = test_input($_POST["subject"]);
// check if subject only contains letters and whitespace
if (!preg_match("/^[a-zA-Z-' ]*$/",$subject)) {
$subjectErr = "Only letters and white space allowed";
}
}
// problem type validation:
if (empty($_POST["problem_type"])) {
$problemErr = "Problem type is required";
} else {
$problem_type = test_input($_POST["problem_type"]);
}
// description validation:
if (empty($_POST["description"])) {
$descriptionErr = "A Description is required";
} else {
$description = test_input($_POST["description"]);
}
}
function test_input($data) {
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
if ($staffErr == "" && $emailErr == "" &&$subjectErr == "" &&$problemErr == "" &&$descriptionErr == "") {
header("Location: insert_logs.php");
exit();
} else {
header("Location: log-it-reportsbeta.php");
exit();
}
?>

Answer 1

This basic php codes below should give you the ideas for 3 states of a form submission process to adjust your code properly.
success
system failure (bug or a temp. server issue for example)
invalid user data input
// data were valid && script's aim is achieved
if (isset($_SESSION['state']) && $_SESSION['state'] == 1) {
// your thanks/result page's content here;
echo 'Thanks. Transaction was successful.';
unset($_SESSION['state']);
return; // not to continue
}
// form not submitted yet
if ( false === (isset($_POST['submit']) && $_POST['submit'] = "your val")) {
require 'form.php';
return; // not to continue
}
// form submitted
require 'validate.php'; // PHP codes to validate data from POST global var.
// data are valid
if (valid($_POST)) {
// try what you aim with valid data
require 'perform_aim.php';
if (perform_aim_successful()) { // for example: record was inserted
$_SESSION['state'] = 1; // success state
header("Location: YOUR URL", TRUE, 301); // prevents reprocessing by F5 ($_POST is empty again by 301.)
exit; // exit after a redirect
}
else {
echo 'Your data was OK but script was failed. Try again later';
}
}
// invalid data
else {
print_r($err_msgs); // error messages from/by 'validate.php'
require 'form.php';
}