What is "Source Tree" in the Xcode preferences and what can I do with it?

Question

I've been recently researching how I can manage source files in a project or multiple projects. I've read that Xcode has a built-in support for using svn, and will support git as well, both of which I found to be very useful.

The one thing I couldn't understand clearly is about Source Trees described in Xcode Project Management Guide. Here is my theory, but as I couldn't really verify this from anywhere (as far as I could tell), I would really like if someone could say what I'm missing, if any.

• A Source Tree in Xcode preferences is more like a root of a source tree, which is a folder in my local file system.
• I can use any files in any of my Xcode projects, even if the files are not in the project folders, if I can specify the files' location related to one of my source trees.
• Now someone has the same project folder that is synchronized with mine. She has all files in the project folder, but the files referenced by a relative location to the source tree may exist out of the project folder.
• But she has a source tree, with the same Setting Name to mine, (but absolutely in a different folder in her local file system), and if she has the file in the same relative location, then her Xcode can access the file without a problem.

So is this correct, and we use source trees because it enables us collaborating with files outside the project folder?

And even if the files outside the project folder is referenced by a relative path to the project folder itself (not to a source tree), if these files are all managed by SVN so they exist in the same relative location to the project folder in everyone's environments, then I wouldn't need source trees, right?

Answer 1

I never think I am an expert of Xcode, but it seems your question hasn't been answered for a while, so maybe it's worth commenting what I could say:

What you described is pretty much about it. Think is as an environmental variable of an operating system. Typically in a build system made by Autotools, for example, files are referenced by relative paths, such as $PROJECT_HOME/src/common/error.cpp. It doesn't matter where $PROJECT_HOME is in each user's local file system, as long as files are accessible by their relative paths to the user's $PROJECT_HOME directory.

And yes, you don't need to use source tree if the entire folder hierarchy used for a project is referenced by relative paths to the project home and somehow it is certain that everyone has the same files in the same location (for example, because a version control repository contains every files in a chunk as you said).

However, I think it's the best to keep all files in the project home folder, unless they are used across multiple projects, and therefore your version control repository only contains a single root directory (the project home) for your project. If there are files that are best to be shared by multiple projects, then I would have a separate repository for those files. In this case all of your coworkers must use the same protocol, say, having a source tree with the same setting name and put all project homes retrieved from your version control server directly under the source tree (so files outside a project home can be referenced in relation to the source tree for all programmers).

The most of my answer is kind of rephrasing what you already described, but that's how I use the source trees feature in Xcode myself. Maybe others can tell you more about it.