php - stop php if empty textbox and process other html forms - php

Question

Below is the code I have, which checks for if text box is empty then give warning beside text box once clicked on Submit.
<?php
if(isset($_POST["submit"])) {
$fqdn = $_POST["fqdn"];
$ip = $_POST["ip"];
$fileText = $fqdn."\n".$ip;
$file = fopen("inputFile.txt","w");
fwrite($file, $fileText);
fclose($file);
}
?>
<form action = "<?php $_PHP_SELF ?>" method = "post">
<table style= "width:400px">
<tr class="spaceUnder">
<td><b>FQDN:</b></td>
<td><input type="text" name="fqdn" placeholder="server.domain.com"/></td>
<td> <?php if(isset($_POST['fqdn']) && $_POST['fqdn'] == ''){ echo "<font color='red'>FQDN cannot be empty</font>";} ?> </td>
</tr>
<tr class="spaceUnder">
<td><b>IP:</b></td>
<td><input type="text" name="ip" placeholder="***.***.***.***"/></td>
<td> <?php if(isset($_POST['ip']) && $_POST['ip'] == ''){ echo "<font color='red'>IP cannot be empty</font>"; } ?> </td>
</tr>
<tr>
<td align="center" colspan="2">
<input type = "submit" name="submit" value="Submit"/>
</td>
</tr>
</table>
</form>
After clicking on submit, the php is still going and writing to the file. If i give exit() or return false; at the below step:
<td> <?php if(isset($_POST['fqdn']) && $_POST['fqdn'] == ''){ echo "<font color='red'>FQDN cannot be empty</font>"; exit();} ?> </td>
the form becomes incomplete, means, the IP textbox and submit button will not exist. Any way to make it right?

Answer 1

So what we have here. We are making 2 variables that will dispay our errors. The variable in first place are emty because we dont know what we have post. After we post the data we can see if the post is emty or not. If the post is emty we assign an error message to the variable and dispay it to our table.
$error_FQDN = "";
$error_ip = "";
if(isset($_POST["submit"])) {
if($_POST["fqdn"] == "" || $_POST["ip"] == ""){
if($_POST["fqdn"] == ""){
$error_FQDN = "FQDN cannot be empty!";
}
if($_POST["ip"] == ""){
$error_ip = "IP cannot be empty!";
}
} else {
$fqdn = $_POST["fqdn"];
$ip = $_POST["ip"];
$fileText = $fqdn."\n".$ip;
$file = fopen("inputFile.txt","w");
fwrite($file, $fileText);
fclose($file);
}
}
<form action = "<?php $_PHP_SELF ?>" method = "post">
<table style= "width:400px">
<tr class="spaceUnder">
<td><b>FQDN:</b></td>
<td><input type="text" name="fqdn" placeholder="server.domain.com"/></td>
<td><?php echo $error_FQDN ?></td>
</tr>
<tr class="spaceUnder">
<td><b>IP:</b></td>
<td><input type="text" name="ip" placeholder="***.***.***.***"/></td>
<td><?php echo $error_ip ?></td>
</tr>
<tr>
<td align="center" colspan="2">
<input type = "submit" name="submit" value="Submit"/>
</td>
</tr>
</table>
</form>

Answer 2

Try this,
// Check for form submit and if fields aren't empty
if(isset($_POST["submit"]) && $_POST['fqdn'] != "" && $_POST['ip'] != "") {
$fqdn = $_POST["fqdn"];
$ip = $_POST["ip"];
$fileText = $fqdn."\n".$ip;
$file = fopen("inputFile.txt","w");
fwrite($file, $fileText);
fclose($file);
}
By validating fqdn and ip, if values aren't empty, if case will be executed. Else it simply won't run.