Question

Sorry for the title, I really didn’t know how to say this…

I often have a string that needs to be cut after X characters, my problem is that this string often contains special characters like : & egrave ;

So, I’m wondering, is their a way to know in php, without transforming my string, if when I am cutting my string, I am in the middle of a special char.

Example

This is my string with a special char : è - and I want it to cut in the middle of the "è" but still keeping the string intact

so right now my result with a sub string would be :

This is my string with a special char : &egra

but I want to have something like this :

This is my string with a special char : è

Answer 1

The best thing to do here is store your string as UTF-8 without any html entities, and use the mb_* family of functions with utf8 as the encoding.

But, if your string is ASCII or iso-8859-1/win1252, you can use the special HTML-ENTITIES encoding of the mb_string library:

$s = 'This is my string with a special char : è - and I want it to cut in the middle of the "è" but still keeping the string intact';
echo mb_substr($s, 0, 40, 'HTML-ENTITIES');
echo mb_substr($s, 0, 41, 'HTML-ENTITIES');

However, if your underlying string is UTF-8 or some other multibyte encoding, using HTML-ENTITIES is not safe! This is because HTML-ENTITIES really means “win1252 with high-bit characters as html entities”. This is an example of where this can go wrong:

// Assuming that é is in utf8:
mb_substr('é ', 0, 2, 'HTML-ENTITIES') === 'é'
// should be 'é '

When your string is in a multibyte encoding, you must instead convert all html entities to a common encoding before you split. E.g.:

$strings_actual_encoding = 'utf8';
$s_noentities = html_entity_decode($s, ENT_QUOTES, $strings_actual_encoding); 
$s_trunc_noentities =  mb_substr($s_noentities, 0, 41, $strings_actual_encoding);