通过PHP中的字符串引用和调用方法是一个坏主意吗？

Question

I've always worry about calling methods by referencing them via strings.

Basically in my current scenario, I use static data mapper methods to create and return an array of data model objects (eg. SomeDataMapper::getAll(1234)). Models follow the Active Record design pattern. In some cases, there could be hundreds of records returned, and I don't want to put everything into memory all at once. So, I am using an Iterator to page through the records, as follows

$Iterator = new DataMapperIterator('SomeDataMapper', 'getAll', array(1234));

while ($Iterator->hasNext()) {
  $data = $Iterator->next();
}

Is that a good way of doing this? Is it a bad idea to pass as strings the name of the mapper class and the method? I worry that this idea is not portable to other languages. Is this generally true for languages like Ruby and Python? If so, can anyone recommend a good alternative?

FYI, for future peoples' refernce, I call the method like this:

$method = new ReflectionMethod($className, $methodName);
$returnValue = $method->invokeArgs(null, $parameters);

Answer 1

It is an acceptable way of doing it. Both Python and Ruby support it and thus should be portable. Python can do it as easily as PHP can, however Ruby has a little more to it. In Python at least, it is useful for when the particular class you're referencing has not yet been imported nor seen yet in the file (i.e. the class is found lower in the same file as where you're trying to reference it.)

Getting a class object from a string in Ruby: http://infovore.org/archives/2006/08/02/getting-a-class-object-in-ruby-from-a-string-containing-that-classes-name/