PHP constant problem

Hi there

I'm working on a class in a PHP web app which defines a number of class constants. It turns out that we want these constants to be initialised to different values and not modified again, depending on a certain condition being true.

I realise class constants can only be assigned values when they are declared, and that a variable is more appropriate for what we want, but these constants are referred to in hundreds of places, and I want to minimise the code change elsewhere in the app.

I've tried creating two new classes, each containing a set of consts with names common to both files, but assigning them different values. Depending on a particular conditional statement being true or false, I then include one of the class files and assigning the original class constants I mentioned the values in the included PHP file.

However, this seems to work in some places and not in others. In some files that include the class with the constants defined, they successfully reference the constants and they contain the correct value.

In other files though, though, I simply get an error :" Undefined class constant 'Classname::constantname.' The files that experience the error are in a different directory, but the include paths are accurate, it's just it doesn't seem to know anything about the values.

Any ideas? Cheers