Using php arrays to validate form information - php

Question

I am not sure if this question has been answered in round about ways through other questions but...
I am creating a web page for my job which has multiple entry fields (all of which have the same validation code). The following is a small section of my php code:
if ($_SERVER["REQUEST_METHOD"] == "POST") {
if (empty($_POST["bottomair"])) {
$bottomairerror = "Maketable bottom air temp is required";
} else {
$bottomair = test_input($_POST["bottomair"]);
if (!filter_var($bottomair, FILTER_VALIDATE_INT, array("options" => array("min_range"=>$coldmin, "max_range"=>$coldmax)))) {
$bottomairerror = $errormsg;
}
}
if (empty($_POST["topair"])) {
$topairerror = "Maketable top air temp is required";
} else {
$topair = test_input($_POST["topair"]);
if (!filter_var($topair, FILTER_VALIDATE_INT, array("options" => array("min_range"=>$coldmin, "max_range"=>$coldmax)))) {
$topairerror = $errormsg;
}
}
if (empty($_POST["meat"])) {
$meaterror = "Maketable meat temp is required";
} else {
$meat = test_input($_POST["meat"]);
if (!filter_var($meat, FILTER_VALIDATE_INT, array("options" => array("min_range"=>$coldmin, "max_range"=>$coldmax)))) {
$meaterror = $errormsg;
}
}
if (empty($_POST["cheese"])) {
$cheeseerror = "Maketable cheese temp is required";
} else {
$cheese = test_input($_POST["cheese"]);
if (!filter_var($cheese, FILTER_VALIDATE_INT, array("options" => array("min_range"=>$coldmin, "max_range"=>$coldmax)))) {
$cheeseerror = $errormsg;
}
}
if (empty($_POST["walkin"])) {
$walkinerror = "Walk-In temp is required";
} else {
$walkin = test_input($_POST["walkin"]);
if (!filter_var($walkin, FILTER_VALIDATE_INT, array("options" => array("min_range"=>$coldmin, "max_range"=>$coldmax)))) {
$walkinerror = $errormsg;
}
}
if (empty($_POST["refrig1"])) {
$refrig1error = "Refrigerator #1 temp is required";
} else {
$refrig1 = test_input($_POST["refrig1"]);
if (!filter_var($refrig1, FILTER_VALIDATE_INT, array("options" => array("min_range"=>$coldmin, "max_range"=>$coldmax)))) {
$refrig1error = $errormsg;
}
}
if (empty($_POST["refrig2"])) {
$refrig2error = "Refrigerator #2 temp is required";
} else {
$refrig2 = test_input($_POST["refrig2"]);
if (!filter_var($refrig2, FILTER_VALIDATE_INT, array("options" => array("min_range"=>$coldmin, "max_range"=>$coldmax)))) {
$refrig2error = $errormsg;
}
}
if (empty($_POST["refrig3"])) {
$refrig3error = "Refrigerator #3 temp is required";
} else {
$refrig3 = test_input($_POST["refrig3"]);
if (!filter_var($refrig3, FILTER_VALIDATE_INT, array("options" => array("min_range"=>$coldmin, "max_range"=>$coldmax)))) {
$refrig3error = $errormsg;
}
}
}
Is there a function which I can use to "tidy up" my php code so that I do not have as many lines to debug when things go sideways with the coding?

Answer 1

I think you only have three options here:
Write perfect code so that your code never goes sideways (highly unlikely for any developer :)
Change from an if structure to a switch structure
Evolve your debugging procedure/tools to make debugging less painful in general.

Answer 2

Create an array with the names of the required fields as a key, and an error message as a value. Then loop through this array. Use the keys in the $_POST superglobal to see if it's been set. If it's not set, throw the error message you defined as the value. Something along the lines of:
$required_parameters = array(
"bottomair" => "Maketable bottom air temp is required",
"topair" => "Maketable top air temp is required",
// etc
);
$errorslist = array();
foreach($required_parameters as $key => $error)
{
if(empty($_POST[$key]))
{
$errorslist[] = $error; // append to list
}
else
{
$test = test_input($_POST[$key]);
if (!filter_var($test, FILTER_VALIDATE_INT, array("options" => array("min_range"=>$coldmin, "max_range"=>$coldmax))))
{
$errorslist[] = $errormsg; // <-- I don't know where you define errormsg, though
}
}
}
You can then loop through the $errorslist array as well to display all errors in a list.