Parse url with pattern in PHP? - php

Question

How to determine, using regexp or something else in PHP, that following urls match some patterns with tokens (url => pattern):
node/11221 => node/%node
node/38429/news => node/%node/news
album/34234/shadowbox/321023 => album/%album/shadowbox/%photo
Thanks in advance!
Update 1
Wrote the following script:
<?php
$patterns = [
"node/%node",
"node/%node/news",
"album/%album/shadowbox/%photo",
"media/photo",
"blogs",
"news",
"node/%node/players",
];
$url = "node/11111/news";
foreach ($patterns as $pattern) {
$result_pattern = preg_replace("/\/%[^\/]+/x", '/*', $pattern);
$to_replace = ['/\\\\\*/']; // asterisks
$replacements = ['[^\/]+'];
$result_pattern = preg_quote($result_pattern, '/');
$result_pattern = '/^(' . preg_replace($to_replace, $replacements, $result_pattern) . ')$/';
if (preg_match($result_pattern, $url)) {
echo "<pre>" . $pattern . "</pre>";
}
}
?>
Could anyone analyze whether this code is good enough? And also explain why there is so many slashes in this part $to_replace = ['/\\\\\*/']; (regarding the replacement, found exactly such solution on the Internet).

Answer 1

If you know the format beforehand you can use preg_match. For example in the first example, you know %node can only be numbers. Matching multiples should be as as easy as we did it earlier, just store the regex in the array:
$patterns = array(
'node/%node' => '|node/[0-9]+$|',
'node/%node/news' => '|node/[0-9]+/news|',
'album/%album/shadowbox/%photo' => '|album/[0-9]+/shadowbox/[0-9]+|',
'media/photo' => '|media/photo|',
'blogs' => '|blogs|',
'news' => '|news|',
'node/%node/players' => '|node/[0-9]+/players|',
);
$url = "node/11111/players";
foreach ($patterns as $pattern => $regex) {
preg_match($regex, $url, $results);
if (!empty($results)) {
echo "<pre>" . $pattern . "</pre>";
}
}
Notice how I added the question mark $ to end of the first rule, this will insure that it doesn't break into the second rule.

Answer 2

Here is the generic solution to the solution above
<?php
// The url part
$url = "/node/123/hello/strText";
// The pattern part
$pattern = "/node/:id/hello/:test";
// Replace all variables with * using regex
$buffer = preg_replace("(:[a-z]+)", "*", $pattern);
// Explode to get strings at *
// In this case ['/node/','/hello/']
$buffer = explode("*", $buffer);
// Control variables for loop execution
$IS_MATCH = True;
$CAPTURE = [];
for ($i=0; $i < sizeof($buffer); $i++) {
$slug = $buffer[$i];
$real_slug = substr($url, 0 , strlen($slug));
if (!strcmp($slug, $real_slug)) {
$url = substr($url, strlen($slug));
$temp = explode("/", $url)[0];
$CAPTURE[sizeof($CAPTURE)+1] = $temp;
$url = substr($url,strlen($temp));
}else {
$IS_MATCH = False;
}
}
unset($CAPTURE[sizeof($CAPTURE)]);
if($IS_MATCH)
print_r($CAPTURE);
else
print "Not a match";
?>
You can pretty much convert the code above into a function and pass parameters to check against the array case. The first step is regex to convert all variables into * and the explode by *. Finally loop over this array and keep comparing to the url to see if the pattern matches using simple string comparison.

Answer 3

As long as the pattern is fixed, you can use preg_match() function:
$urls = array (
"node/11221",
"node/38429/news",
"album/34234/shadowbox/321023",
);
foreach ($urls as $url)
{
if (preg_match ("|node/([\d]+$)|", $url, $matches))
{
print "Node is {$matches[1]}\n";
}
elseif (preg_match ("|node/([\d]+)/news|", $url, $matches))
{
print "Node is {$matches[1]}\n";
}
elseif (preg_match ("|album/([\d]+)/shadowbox/([\d]+)$|", $url, $matches))
{
print "Album is {$matches[1]} and photo is {$matches[2]}\n";
}
}
For other patterns to match, adjust as necessary.