iOS，是否可以从文件中读取objective - C代码并在程序的特定点执行?

I have a bunch of drawing code (primitive drawing, mostly bezier path drawing calls) thats stored in a couple of files and the draw code runs to about a few hundred lines. I wanted to know if its possible to read this code from a file and execute it at a particular point in my program (maybe a draw method of a UIView), much like what we do with shaders in openGL 2.0.I have a bunch of drawing code (primitive drawi