htmlentites not working for emoji - php

Question

I am trying to show a characters html entity
echo htmlentities(htmlentities("&"));
//outputs &
echo htmlentities(htmlentities("<"));
//outputs <
but it does not seem to work with emoji
echo htmlentities(htmlentities("😎"));
//outputs 😎
How can I get it to output 😎?
Edit:
I am trying to display a string input by the user with all of the html entities encoded.
echo htmlentities(htmlentities($input))
Example:
"this & that 😎" -> "this & that 😎"

Answer 1

This works for regular HTML entities, UTF-8 emoticons (and other utf stuff) as well as regular strings of course.
I was just having trouble with empty string value, so I had to put this condition into the function.
function entities( $string ) {
$stringBuilder = "";
$offset = 0;
if ( empty( $string ) ) {
return "";
}
while ( $offset >= 0 ) {
$decValue = ordutf8( $string, $offset );
$char = unichr($decValue);
$htmlEntited = htmlentities( $char );
if( $char != $htmlEntited ){
$stringBuilder .= $htmlEntited;
} elseif( $decValue >= 128 ){
$stringBuilder .= "&#" . $decValue . ";";
} else {
$stringBuilder .= $char;
}
}
return $stringBuilder;
}
// source - http://php.net/manual/en/function.ord.php#109812
function ordutf8($string, &$offset) {
$code = ord(substr($string, $offset,1));
if ($code >= 128) { //otherwise 0xxxxxxx
if ($code < 224) $bytesnumber = 2; //110xxxxx
else if ($code < 240) $bytesnumber = 3; //1110xxxx
else if ($code < 248) $bytesnumber = 4; //11110xxx
$codetemp = $code - 192 - ($bytesnumber > 2 ? 32 : 0) - ($bytesnumber > 3 ? 16 : 0);
for ($i = 2; $i <= $bytesnumber; $i++) {
$offset ++;
$code2 = ord(substr($string, $offset, 1)) - 128; //10xxxxxx
$codetemp = $codetemp*64 + $code2;
}
$code = $codetemp;
}
$offset += 1;
if ($offset >= strlen($string)) $offset = -1;
return $code;
}
// source - http://php.net/manual/en/function.chr.php#88611
function unichr($u) {
return mb_convert_encoding('&#' . intval($u) . ';', 'UTF-8', 'HTML-ENTITIES');
}
/* ---- */
var_dump( entities( "&" ) ) . "\n";
var_dump( entities( "<" ) ) . "\n";
var_dump( entities( "😎" ) ) . "\n";
var_dump( entities( "☚" ) ) . "\n";
var_dump( entities( "" ) ) . "\n";
var_dump( entities( "A" ) ) . "\n";
var_dump( entities( "Hello 😎 world" ) ) . "\n";
var_dump( entities( "this & that 😎" ) ) . "\n";

Answer 2

$emoji = "\xF0\x9F\x98\x8E"; // its your emoji
I get this callback from convert unicode to html entities hex
$hex = preg_replace_callback('/[\x{80}-\x{10FFFF}]/u', function ($m) {
$char = current($m);
$utf = iconv('UTF-8', 'UCS-4', $char);
return sprintf("&#x%s;", ltrim(strtoupper(bin2hex($utf)), "0"));
}, $emoji);
echo $hex;
echo json_encode(("\xF0\x9F\x98\x8E")); // its decoded. htmlentities doesn't work with it.
Is this OK ?

Answer 3

htmlentities documentation states that
all characters which have HTML character entity equivalents are
translated into these entities.
Your emoji does not have an equivalent like < is for <, so it doesn't get converted. 😎 is just an HTML code, not an HTML entity.
function htmlEntitiesOrCode($string) {
//try htmlentities first
$result = htmlentities($string, ENT_COMPAT, "UTF-8");
//if the output is different from input, an entity was returned
if ($result != $string) {
return $result;
}
//get the html code
$offset = 0;
$code = ord(substr($string, $offset,1));
if ($code >= 128) {
if ($code < 224) {
$bytesnumber = 2;
} else if ($code < 240) {
$bytesnumber = 3;
} else if ($code < 248) {
$bytesnumber = 4;
}
$codetemp = $code - 192 - ($bytesnumber > 2 ? 32 : 0) - ($bytesnumber > 3 ? 16 : 0);
for ($i = 2; $i <= $bytesnumber; $i++) {
$offset ++;
$code2 = ord(substr($string, $offset, 1)) - 128;
$codetemp = $codetemp*64 + $code2;
}
$code = $codetemp;
}
$offset += 1;
if ($offset >= strlen($string)) {
$offset = -1;
}
$result = "&#" . $code;
return $result;
}
HTML code function taken from here: http://php.net/manual/en/function.ord.php#109812