Two apps, one codebase. How can I achieve this?

I have an app, it's currently in the app store.

I have an idea for another app, that would share a lot of the same structure as my published app. They're both photo manipulation apps, so the codebase for importing, sharing, saving, rotating, etc. would all be shared between the two. The type of photo manipulation would be different, though.

My thinking is, when I update app #1, I want those changes in app #2, and vice versa.

What is the best way to achieve two apps from one codebase?

Strategies I've contemplated,

1. One project file, two targets. That way the co开发者_运维百科debase for both apps will always be up to date, though the project file/directory will be a little messy, to be sure.
2. Branch the app in git, frequently merge changes between the two branches for the classes used by both.

I'm open to other ideas, too.

I've found people discussing this, but mostly in relation to minor changes... i.e. one app with a few different brandings / data files. My two apps will be reasonably distinct, so I don't think those techniques necessarily apply.

Create a static library with your common photo manipulation or other shared functions, and rework the existing project to add the library as a dependency and use the library's headers folder in the User Header Search Path. Then you can essentially clone your old project and start modifying straight away with access to all of the shared library functions.

Two targets of the same project seems applicable to your situation, though. If you've got a large amount of overlap then you just basically need to write a second UI / workflow for that, right? If yes, using two targets makes a lot of sense.

I suggest split your existing app into TWO parts. Separate out all the common portions as a generic DLL/class library, and use the dll in both your existing and new project.

As the first project development progresses, use the latest version of the dll in your newer project, using appropriate deploy scripts. This way your new project can even be in a seperate codebase

I would suggest you take a look at using git submodules in both your apps. This have worked perfectly for us when sharing code in multiple apps. Basicly we use a structure where we in each Xcode project have a "Components/" folder where we keep submodules.

App A can have the submodules like this:

Components/SomeAmazingPhotoManipulationStuff
Components/MaybeSomeUsefullFoundationThingsYouUseOften

App B might only use:

Components/MaybeSomeUsefullFoundationThingsYouUseOften

The idea here is that you can update your submodule projects seperately and just go into each App where it is used and update submodule to the latest version of the component, successfully sharing stuff between apps without losing version control. It will also scale well to many projects.

And ofcourse you can branch your submodules and have App A use one branch and App B another, if you do some specific stuff or very experimental stuff in one app only or whatever scenario you might think of.

Ever since we started using git submodules like this we have not looked back or even considered any other solution.