Check for URL variable in PHP - php

Question

I have a PHP page that takes a date variable: mypage.php?date=2015-07-14 and displays output.
How do I check if the date= is empty and if it is then insert and refresh the page with the current date?
I've tried to formulate a small script at the top of the page using _GET with the date value but am not sure how to handle the reload of the page?

Answer 1

You can simply check your input is not empty using empty function, and create a date (it will default to current, unless you pass parameter), and passed it as get parameter in header function to the same page.
if(empty($_GET['date']))
header('location:'.$_SERVER['PHP_SELF'].'?date='.date('Y-m-d'));

Answer 2

You can simply use the empty language construct from PHP to check if a date was supplied: http://php.net/empty
Then you could use the header-function to redirect if no date was entered in the url: http://php.net/manual/en/function.header.php
For example:
<?php
if (empty($_GET['date'])) {
header('location: ' . $_SERVER['REQUEST_URI'] . '?date=' . date('Y-m-d'));
}
Also note that any headers should be sent before generating any output in your script.

Answer 3

What you seek is a combination of isset and empty functions with redirect using header. The end result could look something like this
<?php
$rawDate = isset($_GET['date']) && !empty($_GET['date']) ? $_GET['date'] : false;
$requestDateTime = $rawDate ? DateTime::createFromFormat('Y-m-d', $rawDate) : false;
$currentDateTime = new \DateTime();
// If datetime from GET is invalid or is not current date...
if (!$requestDateTime || $currentDateTime->diff($requestDateTime)->days > 0) {
// Redirect to current page with current date
header(sprintf('Location: ?date=%s', $currentDateTime->format('Y-m-d')));
}