PHP How to encode text to numeric entity? - php

Question

I have xml like this:
<formula type="inline">
<default:math xmlns="http://www.w3.org/1998/Math/MathML">
<default:mi>
&Zopf;
</default:mi>
</default:math>
</formula>
My goal is to get rid of all special entities like &Zopf; by replacing them by their numeric entity presentations.
I tried :
$test = <content of the xml>;
$convmap = array(0x80, 0xffff, 0, 0xffff);
$test = mb_encode_numericentity($test, $convmap, 'UTF-8');
But this will not replace the &Zopf; Any idea?
My goal is to get:
ℤ
as shown here: http://www.fileformat.info/info/unicode/char/2124/index.htm
Thank you.

Answer 1

Your converter is converting your LaTeX into MathML, not HTML entities. You need something that converts directly into HTML character references, or a MathML to HTML character reference converter.
You should be able to use htmlentities:
htmlentities($symbolsToEncode, ENT_XML1, 'UTF-8');
http://pt1.php.net/htmlentities
You can change ENT_XML1 to ENT_SUBSTITUTE and it will return Unicode Replacement Characters or Hex character references.
As an alternative, you could use strtr to convert the characters to something you specify:
$chars = array(
"\x8484" => "蒄"
...
);
$convertedXML = strtr($xml, $chars);
http://php.net/strtr
Someone has done something similar on GitHub.

Answer 2

So you need to decode the named entities first:
function decodeNamedEntities($string) {
static $entities = NULL;
if (NULL === $entities) {
$entities = array_flip(
array_diff(
get_html_translation_table(HTML_ENTITIES, ENT_COMPAT | ENT_HTML5, 'UTF-8'),
get_html_translation_table(HTML_ENTITIES, ENT_COMPAT | ENT_XML1, 'UTF-8')
)
);
}
return str_replace(array_keys($entities), $entities, $string);
}
After that you can use htmlentities to encode them in a different format if it is really needed.