Here is my use case, which requires an exceptional amount of encoding. Maybe you think it contrived, but we run this on production. Coincidently, this covers every type of encoding, so I'm posting as a tutorial.
Somebody just bought a prepaid gift card ("token") on our website. Tokens have corresponding URLs to redeem them. This customer wants to email the URL to someone else. Our web page includes a mailto
link that lets them do that.
// The order system generates some opaque token
$token = 'w%a&!e#"^2(^@azW';
// Here is a URL to redeem that token
$redeemUrl = 'https://httpbin.org/get?token=' . urlencode($token);
// Actual contents we want for the email
$subject = 'I just bought this for you';
$body = 'Please enter your shipping details here: ' . $redeemUrl;
// A URI for the email as prescribed
$mailToUri = 'mailto:?subject=' . rawurlencode($subject) . '&body=' . rawurlencode($body);
// Print an HTML element with that mailto link
echo '<a href="' . htmlspecialchars($mailToUri) . '">Email your friend</a>';
Note: the above assumes you are outputting to a text/html
document. If your output media type is text/json
then simply use $retval['url'] = $mailToUri;
because output encoding is handled by json_encode()
.
You should see:
"args": {
"token": "w%a&!e#\"^2(^@azW"
},
And of course this is the JSON representation of $token
above.
You can use URL Encoding Functions PHP has the
rawurlencode()
function
ASP has the
Server.URLEncode()
function
In JavaScript you can use the
encodeURIComponent()
function.
Based on what type of RFC standard encoding you want to perform or if you need to customize your encoding you might want to create your own class.
/**
* UrlEncoder make it easy to encode your URL
*/
class UrlEncoder{
public const STANDARD_RFC1738 = 1;
public const STANDARD_RFC3986 = 2;
public const STANDARD_CUSTOM_RFC3986_ISH = 3;
// add more here
static function encode($string, $rfc){
switch ($rfc) {
case self::STANDARD_RFC1738:
return urlencode($string);
break;
case self::STANDARD_RFC3986:
return rawurlencode($string);
break;
case self::STANDARD_CUSTOM_RFC3986_ISH:
// Add your custom encoding
$entities = ['%21', '%2A', '%27', '%28', '%29', '%3B', '%3A', '%40', '%26', '%3D', '%2B', '%24', '%2C', '%2F', '%3F', '%25', '%23', '%5B', '%5D'];
$replacements = ['!', '*', "'", "(", ")", ";", ":", "@", "&", "=", "+", "$", ",", "/", "?", "%", "#", "[", "]"];
return str_replace($entities, $replacements, urlencode($string));
break;
default:
throw new Exception("Invalid RFC encoder - See class const for reference");
break;
}
}
}
Use example:
$dataString = "https://www.google.pl/search?q=PHP is **great**!&id=123&css=#kolo&[email protected])";
$dataStringUrlEncodedRFC1738 = UrlEncoder::encode($dataString, UrlEncoder::STANDARD_RFC1738);
$dataStringUrlEncodedRFC3986 = UrlEncoder::encode($dataString, UrlEncoder::STANDARD_RFC3986);
$dataStringUrlEncodedCutom = UrlEncoder::encode($dataString, UrlEncoder::STANDARD_CUSTOM_RFC3986_ISH);
Will output:
string(126) "https%3A%2F%2Fwww.google.pl%2Fsearch%3Fq%3DPHP+is+%2A%2Agreat%2A%2A%21%26id%3D123%26css%3D%23kolo%26email%3Dme%40liszka.com%29"
string(130) "https%3A%2F%2Fwww.google.pl%2Fsearch%3Fq%3DPHP%20is%20%2A%2Agreat%2A%2A%21%26id%3D123%26css%3D%23kolo%26email%3Dme%40liszka.com%29"
string(86) "https://www.google.pl/search?q=PHP+is+**great**!&id=123&css=#kolo&[email protected])"
* Find out more about RFC standards: https://datatracker.ietf.org/doc/rfc3986/ and urlencode vs rawurlencode?
The cunningly-named urlencode() and urldecode().
However, you shouldn't need to use urldecode()
on variables that appear in $_POST
and $_GET
.
Source: Stackoverflow.com