How to differentiate between two forms using $_SERVER["REQUEST_METHOD"] == "POST"

Question

Hi, I am currently working on a project that implements this technique. However, how do you go about differentiating two forms on the same page? For example:

if($_SERVER["REQUEST_METHOD"] == "POST") {
      $search = trim(filter_input(INPUT_POST,"user_search",FILTER_SANITIZE_SPECIAL_CHARS));
      $search = preg_replace("#[^0-9a-z]#i", "", $search);

  if($search == "") {
    $error_message = "Please enter something before submitting";
  }
}

Later on in this code segment, an SQL query would be performed if the $error_message was not set.

I want another form on the same page that applies the same principles as this... It stores the user's input into a variable which is sanitized and trimmed and uses the same error checking above (checking if the user's input was empty, etc). However I feel this code would look quite messy and disorganised.

What are some ways of differentiating between two forms on the same page?

Answer 1 · 2016-04-14T18:33:31Z

April 14, 2016 6:33pm

I think the easiest way to distinguish the difference between two form submissions, is by adding a hidden input type in your form markup. For example:

<form action="someprocessing.php" method="post">
    <input type="text" name="user_search">
    <input type="hidden" name="number1" value="number1">
    <input type="submit">
</form>
<form action="someprocessing.php" method="post">
    <input type="text" name="user_search">
    <input type="hidden" name="number2" value="number2">
    <input type="submit">
</form>

Your global $_POST variable will hold the value of either the number1 or number2 input field, depending on which form has been submitted. I would check on that like this:

// Returns number1 or number2 string value depending on which form is submitted. If none, return null.
function whatFormHasBeenSubmitted()
{
    if ( !empty( $_POST["number1"] ) ) {
        return "number1";
    } elseif ( !empty( $_POST["number2"] ) ) {
        return "number2";
    } else {
        return null;
    }
}

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James Barrett

James Barrett

How to differentiate between two forms using $_SERVER["REQUEST_METHOD"] == "POST"

1 Answer

Lee Ravenberg

Lee Ravenberg