(rails) how to validate whether an uploaded .txt file is not, say, an image file?
I have a upload text file field, and with it I plan to save the file somewhere and then store the location of the file in a database. However, I want to make sure the file they uploaded is a .txt file, and not, say, an image file. I imagine this happens in the validation step. How does one validate such a thing? Also, how do you get the ...