php xml_parser UTF-8编码值被拆分

Question

I am not sure if this is the correct behavior and how to effectively deal with it. I have defined an xml parser in php and it looks like this:

$xml_parser = xml_parser_create();
xml_parser_set_option($xml_parser, XML_OPTION_TARGET_ENCODING, 'UTF-8');
xml_parser_set_option($xml_parser,XML_OPTION_SKIP_WHITE,1);
xml_set_element_handler($xml_parser, "startElement", "endElement");
xml_set_character_data_handler($xml_parser, "characterData"); 
(....)   
function characterData($parser, $data){    print('<p>|' . $data . '|</p>');}

The input xml is like this:

<?xml version="1.0" encoding="UTF-8"?>
<fields><field name="address"><value>aą</value></field></fields>

And the output looks like this:

|a|
|ą|

I was expecting it to look like this:

|aą|

Why does php split the UTF-8 encoded string into separate values??

Answer 1

The answer is in the documentation :

It can be called multiple times inside each fragment (eg for non-ASCII strings).

Your code just needs to be able to handle that.