Looking to finish my url encoding in php - php

Question

I have a slug function that I am using from another tutorial.
public function createSlug($slug) {
// Remove anything but letters, numbers, spaces, hypens
// Remove spaces and duplicate dypens
// Trim the left and right, removing any left over hypens
$lettersNumbersSpacesHypens = '/[^\-\s\pN\pL]+/u';
$spacesDuplicateHypens = '/[\-\s]+/';
$slug = preg_replace($lettersNumbersSpacesHypens, '', mb_strtolower($slug, 'UTF-8'));
$slug = preg_replace($spacesDuplicateHypens, '-', $slug);
$slug = trim($slug, '-');
return $slug;
}
It works great. I have two questions.
It gives me 'amp' instead of removing the '&' symbol. Not sure if it should be like that.
For eg.
original url
http://www.mywebsite.com?category_id=1&category_name=hot & dogs
new url using slug function
http://www.mywebsite.com?category_id=1&category_name=hot-amp-dogs
and second, how do I decode it back to the original form so that I can echo it out on the page? It doesn't look right echoing with dashes.

Answer 1

Use "htmlspecialchars_decode". see below modified function:
function createSlug($slug) {
// Remove anything but letters, numbers, spaces, hypens
// Remove spaces and duplicate dypens
// Trim the left and right, removing any left over hypens
$slug = htmlspecialchars_decode($slug);
$lettersNumbersSpacesHypens = '/[^\-\s\pN\pL]+/u';
$spacesDuplicateHypens = '/[\-\s]+/';
$slug = preg_replace($lettersNumbersSpacesHypens, '', mb_strtolower($slug, 'UTF-8'));
$slug = preg_replace($spacesDuplicateHypens, '-', $slug);
$slug = trim($slug, '-');
return $slug;
}
For decode, agree with Rakesh Sharma. Use database to manage this.