将输入字段保留在下一页

Question

I have a date filter for entries from database. On the first page i have a list of all entries. On the second i have the same filter and almost filtered by date list. So i want to keep values of filter from the first page.

Here is my code :

 <form action="filter.php" method="post"> <label>From</label><input name="from" required="true" type="date"/> <label>To:</label> <input name="to" required="true" type="date"/> <input name="" type="submit" value="Search" /> </form> <table> ... ... ... </table>

Answer 1

You can access the variable after pressing submit.. Therfore you have to change <input name="" type="submit" value="Search" /> to <input name="submit" type="submit" value="Search" />

<?php

   if(isset($_POST['submit'])) {
      $from = $_POST['from'];
      $to = $_POST['to'];
   }

?>

You can also store the variable into sessions, to access it from everywhere.

<?php
   session_start();

   if(isset($_POST['submit'])) {
      $from = $_POST['from'];
      $to = $_POST['to'];
      $_SESSION['from'] = $from;
      $_SESSION['to'] = $to;
   }
?>

The third option would be, to set the method of the form element to method="GET" . After that you can access the values through:

<?php
   if(isset($_GET['submit'])) {
      $from = $_GET['from'];
      $to = $_GET['to'];
   }
?>

With the get Parameter you can also do a magic thing like: http://www.example.com/index.php?from=20150906&to=20150907 . So you get the values of the variable via the URL..

For more information see: http://php.net/manual/en/reserved.variables.php

I hope I could help you...

Answer 2

In your case, since you are using POST , you can access the values

if(isset($_POST['submit']])) {
    $from = $_POST['from'];
    $to   = $_POST['to'];
}

As user Markus already said, you should change your submit-button name-attribute to a self-explanatory name, to keep it easy to maintain the code and check, if this button was pressed.

You then have to set it via the value -attribute in your form.

 <form action="filter.php" method="post">
     <label>From</label><input name="from" value="<?php echo $from; ?> required="true" type="date"/>
     <label>To:</label> <input name="to" value="<?php echo $from; ?>required="true" type="date"/>
     <input name="submit" type="submit"  value="Search" />
 </form>

Keep in mind, that it is never safe to pass unsanitized data. So you should consider sanitizing the user input. (for instance a given format like YYYY-MM-DD)