正则表达式解决方案以查找正则表达式模式并对其进行解析。

Question

I am trying to write a simple router for PHP. And I am facing some problem. Example of the routes are as follows.

$route = []
$route['index']     = "/"; 
$route['home']      = "/home";
$route['blog']      = "/blog/[a-z]";
$route['article']   = "/article/id/[\d+]/title/[\w+]";

Now if we take the last example, I would like the regex only to look for patterns such as [\\d+] and [\\w+] that is it. I will use explode() to actually cross check if URL contains /blog/ , /id/ and /title/ . I don't want regex's help with that, but only to detect the patterns and match it.

for example. If a given $URL was dev.test/blog/id/11/title/politics

I would need some like: preg_match($route['url'], $URL)

So, now the preg_match() function knows, that after "/article/id/ there is a pattern asking only for a digit to occur, then if the digit is found it will continue parsing, or else it will show fail or 0 .

I don't know much about regex to handle this complex problem.

Answer 1

Your question is a little unclear, but if you want only to capture the [\\d+] or [\\w+] parts of the target string, you should consider using brackets to capture sub-matches, and the (?:xxx) non-capturing match, which checks for the pattern but does not add it to the array, something like:

  $route['article']   = "(?:\/article\/id\/)([\d+])(?:\/title\/)([\w+])";

This will add the matched [\\d+] and [\\w+] to your matches array only. You'll find them like so:

  $matches[0][0] and matches[1][0].

See http://www.regular-expressions.info/tutorial.html for an outstanding tutorial on regexes, by the way.

If you aren't sure of the values of 'article', 'id', and 'title' in advance, then you will probably at least need to be sure of the number of directories given in the url. That means as long as you know the position of the [\\d+] and [\\w+] entries, you could use

    $route['article'] = "(?:\/[\w+]\/[w+]\/)([\d+])(?:\/[\w+]\/)([\w+])"