patch, update and upgrade for an application

Question

Let's say we have a simple calculator application that has

1. GUI
2. Business Logic

Could someone explain to me in detail how could I "make and allow" it to work smoothly with

1. Patch at both the levels
2. Update at both the levels
3. Upgrade at both the levels

Answer 1

If you use standard MSI technology (doesn't matter how it is made) and keep the GUI's and the Upgrade Code the same then the files will update to the new version automatically. You will have to look into the documentation for your installer building technology however to find out how to add a check so that only newer files are added and not older. Best to protect the users from themselves when possible. As for the code, the files are updated when you rebuild your project/solution. As long as you don't change the signatures of the methods in your business logic then it really shouldn't matter what you do behind the scenes.