Add a generic hook function for all escaped entities.
Add a generic hook function for all escaped entities. This is a generic variant of the xml_addentityhook() function. If you use this function, xixml will only use the hook you specify when it can't recognise an entity. In other words, any hooks created without xml_addentityhook() are invalidated.The function you pass must return a pointer to the string to output instead of the encoded entity, as usual. The first argument is also a pointer to the first character after the ampersand.