I want to add GET parameters to URLs that may and may not contain GET parameters without repeating ?
or &
.
Example:
If I want to add category=action
$url="http://www.acme.com";
// will add ?category=action at the end
$url="http://www.acme.com/movies?sort=popular";
// will add &category=action at the end
If you notice I'm trying to not repeat the question mark if it's found.
The URL is just a string.
What is a reliable way to append a specific GET parameter?
Basic method
$query = parse_url($url, PHP_URL_QUERY);
// Returns a string if the URL has parameters or NULL if not
if ($query) {
$url .= '&category=1';
} else {
$url .= '?category=1';
}
More advanced
$url = 'http://example.com/search?keyword=test&category=1&tags[]=fun&tags[]=great';
$url_parts = parse_url($url);
// If URL doesn't have a query string.
if (isset($url_parts['query'])) { // Avoid 'Undefined index: query'
parse_str($url_parts['query'], $params);
} else {
$params = array();
}
$params['category'] = 2; // Overwrite if exists
$params['tags'][] = 'cool'; // Allows multiple values
// Note that this will url_encode all values
$url_parts['query'] = http_build_query($params);
// If you have pecl_http
echo http_build_url($url_parts);
// If not
echo $url_parts['scheme'] . '://' . $url_parts['host'] . $url_parts['path'] . '?' . $url_parts['query'];
You should put this in a function at least, if not a class.