Code reuse is an admirable goal for any developer.
Being able to re-use well written well tested code is a good thing.
Especially if you can reuse it across multiple facets of one project, or across several projects.
And I wouldn’t be surprised if a lot of people start out reusing code using copy paste from one place to another.
However, copy paste isn’t usually a well regarded code reuse technique.
Why not ? Stack overflow wrote a blog about the reasons. You might copy & paste someone else’ insecure code into your projects and thereby introduce security vulnerabilities. That’s certainly a possibility.
But what if you’re just copying & pasting your own code around ? Where’s the harm ?
Suppose you have some code you really think is top notch. And you want to reuse it over & over. Suppose you want to reuse it in the event handler of numerous controls across several projects in Xojo.
And sometime later you find there’s a bug in it.
Now how many places do you have to fix in one project ? Or worse across many projects ?
This is where copy paste as a code reuse technique can cause you extra work.
You have to find & fix all that code in every project you’ve used it in.
I’ve been using externals in SVN (yes I still use SVN)
And in every project that uses these shared modules its a simple “update” and they have all the latest code from all the shared items.
If you have the ability to avoid it by using submodules, includes, sub-projects in whatever version control system you’re using (you ARE using version control right?), or similar mechanisms I’d encourage you to do so.
It will help you avoid the proliferation of many different versions of the same code in all your projects.
And when you need to fix the code you can fix one copy and all your other projects can be updated with it.