Illustrator - two triangles with text

Using illustrator CS6, Is there a way to make only the text on the white triangle be black, and keep the part on pink still white?

I do it manually, by making two copies of the text one with white background, one black, making an image and slicing it, but just thinking there might be an easier way.

I've tried arranging different layers

Answer

One way of doing it is making a Clipping Mask.

You have to make another triangle like the pink one but from the other side (bottom-left corner) and make it black, then copy and paste-in-place the text, go to Object > Clipping Mask > Make .

You will end up with this:

PS: There are other ways of doing this, but the ones that I know of involve Outlining the text, this would not preserve the text's editable state but with the clipping mask it does, the only bad thing is that you have to change the text in both the original text that's left below your clipping mask and it's white, and the one in the clipping mask itself.