Best practices for MacOS/iPhone library cross compiling - iphone

I've build a static library working nice in a Cocoa Touch environment. Now I'd like to compile it also for Cocoa.. Can I have a single XCode project with different sdk targets? Is there some resource out there able to give hints about best the practices in this (and other) sense?

This last two months I have been working on exactly this task ( cross compiling static library for iPhone/Android/Mac OS/Linux/Windows...
It is certainly possible, a nice way, is adding an external xcode project as a target to your first xcode project. So you create a new "Active Configuration" for Mac OS X, iPhone and other platforms that you want to support.
Here, you can find a good tutorial about how to use a secondary Xcode project as a target of your main project to build a static library. It's a cool way because if you debug for example you still have all the symbols of the library, etc.

It can be done but it requires some manual tweaking of the build.
Start with the Xcode Build System Guide.
As an informal way of accomplishing this, you can create two separate projects and add references for exact same set of library source files to each project. Set one project to compile for Cocoa-Touch and the other for Cocoa. If both projects reference the same files, changes made in one project will be automatically reflected in the other. (If you have both projects open, Xcode will complain that the file has been changed by another app but otherwise it won't notice.)
I have a utility class that I continually dump new methods in. I add it to every project and just park methods as I need it. The new methods show up in old projects because the source files are shared across all the projects.

Related

Organizing Different Versions of App in Xcode

I'm developing an iPhone app that can edit images. Ultimately, I want to have a small version that allows the user to simply edit their images, and a large version that allows social networking of the images. Then I'd like to develop a version of each for the iPad.
Being that this is my first foray into commercial mobile development, I'm confused about how to organize all these versions in Xcode. Obviously, there will be file reuse shared between each version. I guess my question is, how do I go about organizing these separate projects in the most efficient way so that they share files and so when I edit a particular file that is shared, the changes are made to each version of the application? Is there some kind of construct to follow in XCode?
Are there any links or literature on how to go about doing this? (was not sure the correct term to search for it).
Remember: If you find yourself repeating/duplicating something, suspect that you're doing it wrong.
Your Xcode project will have 4 targets in this scenario. The basic target layout for this setup looks like this:
A Static Library (for your shared source files)
A Resource Bundle (for your shared resources)
App-Full (Universal)
App-Lite (Universal)
The apps link to the shared static library, and copy the resource bundle.
Naturally, apps will have sources/libraries/dependencies which differ -- those go in the app target (or some other dependency).
Given your background: Plan on it taking a good amount of time (initially and as you go) and patience to figure out how these dependencies should be composed, used, and maintained.
I would suggest keeping the "lite" and "full" projects separate but within the same workspace. That way you can keep the shared files in one project and simply use a shared reference to them in the other. All changes made to the shared files from either project will affect both.
As far as iPhone/iPad versions, I would also suggest that you keep these apps completely separate but within the same workspace (so that they can share code) as well. If you look around about the suggestions for managing both apps in a single project (aka, universal app), the only real benefit is that customers can buy one app and can download it on either device and some may get upset if that isn't available to them. If your app is free, don't worry about it.
Lastly, a caveat about workspaces, you need to uniquely name your files across all projects. For example if you're working with a project that uses a MainViewController.h subclass and another project that uses a MainViewController.h subclass, you could assign or edit the wrong one by accident regardless of what project you're in, so be wary. If using unique file names is a problem, you can bypass using workspaces by simply creating an empty project to dump all of your shared code into and then add references to your standalone apps from there.
If you choose to keep various copies of your project for different functionality, it will be eventually confusing, as there are places when XCode offers you one thing instead of another. One such place is - when you open a project from location X, it will also show you your copy from location Y since you opened it last time. As a result, you are likely to commit more mistakes. Organizer is one more such place where you can make mistakes.
XCode is self-contained enough to maintain both iPhone and iPad versions. You will have two separate storyboards which can be made part of one project if you chose universal as the type of app.
As for various features, you shouldn't be maintaining separate copies of your project. Instead, recommended way is to keep all features within single project, and have app logic provide access to various features.
XCode keeps version of your build under Targets section when you click project. To maintain multiple versions through your dev cycle, use source code repository (git or svn).

how do I reference a separate project in xcode 4?

How do I reference another project which has code I wish to leverage in XCode 4. In particular I'm trying to make use of the NSDate extensions from here.
Some notes:
I was assuming I should probably reference rather than trying build a framework
I tried copying the existing "Hello World" xcode project file across into my project, however this didn't seem to work
Do I need to create a new "Target" based on "coco touch static library" option?
Then would I need to Edit the current Product Scheme so that when I build the new target would build
What do I need to do on my project side exactly - should going Add Files, and choosing the extensions Xcode Project File be enough?
thanks
I was assuming I should probably reference rather than trying build a framework
yes, reference and link with it, unless you need only a bit of it. at this stage, separating the bits you want may be an advanced topic (depends on the lib's layout/depends as well). you should prefer to reference and link because it will normally minimize your maintenance time, especially if you use it in multiple projects.
I tried copying the existing "Hello World" xcode project file across into my project, however this didn't seem to work
you don't create a project, you add the library's xcode project to your app or library, set the lib as a dependency, add the library to your search paths if needed, then link with the library.
Do I need to create a new "Target" based on "coco touch static library" option?
no
Then would I need to Edit the current Product Scheme so that when I build the new target would build
no. you configure it as a dependency. you may need to alter the lib's build settings if there is a major conflict, which the linker or compiler would point out.
What do I need to do on my project side exactly - should going Add Files, and choosing the extensions Xcode Project File be enough?
start with the process outlined above.
There is no reason to bring in an actually project. Either you can bring in the source files themselves and you could even use the same exact files instead of copying them if you want. However, if you have more than just a few files, and you don't think you will be changing the code much, then creating a static library would probably be the best option.

What exactly is an Target in Xcode?

I was always wondering what's up with those Targets? What is it all about? What's the point of that? I never had to fiddle around with them, but obviously I can. Why should I want that, and what can I do with them? What's their purpose?
Each project can build multiple executables or libraries or call out to a makefile or shell script to build "stuff". Each one of these is a Target.
One iPhone project I have includes a separate target for each static library in my home grown SDK and a shell script target to build the Doxygen docs. Another project includes two targets, one for the app as used by general users, one for an administration & management edition.
In the first example, I need to build each library then link all the static libraries into an SDK test application, so my SDK Test App depends on all the library targets (but not the docs, since I don't need to constantly regen them.)
In the second example, the management and the general versions of the app share a considerable amount of code and resources. When I change one, I want to change them both.
The target is something like a "blueprint". It includes rules that tell the compiler what to do, which sources should be compiled, which files should be copied into the application bundle, which libraries should be linked.
If you want to make a Free-Version of your app one way to do so is to add a new target.
Of course you could just duplicate the whole project but then you had to keep those in sync if you change some code. Using a different targets makes this a lot easier.

Automate the XCode build settings

I've developed a static library that I'd like to share between XCode projects. I did some reading to learn exactly how to include this library as a binary dependency so that it runs on both the device and the simulator and that lead to a couple of manual steps which I'd now like to automate. Overall I'd like to be able to release new versions of my library and have a simple upgrade process for any project using the older version. Currently that process consists of deleting and/or copying the new binary files over the original location, deleting copying over new header files. The initial install consists of the same two steps along with additional project/target level configuration to set conditional linker flags based on the target SDK. Is there a way this could be automated? I mean I know I could do something like write an Applescript to do the heavy lifting but how? Has anyone ever automated xcode build settings via applescript? How would I call into XCode via Applescript? Are there any other alternatives? Is there a better way to maintain binary level dependencies?
Update
I'm looking to maintain a binary level dependency where project A depends on a static library created by project B. Something similar to a framework that can be included into an XCode iPhone project easily. After building "B" I want something that can practically be dropped into and project including A. While I am becoming aware of all the procedures around leveraging such a dependency I am looking for some solutions to soften up all of the rough edges.
Add a custom build script through Xcode:
select your target under the Targets group on the left
select Add -> New Build Phase -> New Run Script Build Phase
double click on the new Run Script item underneath your target
this allows you to write a shell script, accessing most of the Xcode environment variables related to the current build, e.g. $BUILT_PRODUCTS_DIR
if you check the "Show environment variables in build log" and view the detailed build output you can see all the variables available.
Have a Google search and you'll find lots of examples, e.g. section 20.3 here etc.
If you are using Subversion I believe you can use SVN externals to specify which particular version of your library to use.
You just have to drag & drop your library project in your project. xCode will dot the rest...
Regards,
Thierry

Building Two iPhone Apps from Common Code

I have an iPhone app, and I'm taking a few features of the app and creating a new app.
What's the appropriate way to build two apps from a common code base?
One more option nobody seems to have mentioned yet - you can create a new target in the original project file. I do this for "free" and "paid" versions of the same app, but it'd be useful for any two apps that share most of the same code.
I got this from an Xcode expert:
Xcode has two affordances to do the right thing here:
1) For files outside your project tree that your project requires, set up a source tree. Xcode > Preferences > Source Trees, define a symbolic path (e.g. EXTRA_SOURCES) with the actual path on your disk to where they're checked out. Then when you add those files to your project, add them Relative to Source Tree to that source tree.
(N.B. Quit and restart Xcode after defining the source tree in Prefs.)
2) In Xcode 3.2, define the Project Roots to include the Source Tree. Project > Edit Project Settings > General tab, "Configure Roots & SCM" button. Add the source tree to the Project Roots and set up its repository, which can be a separate repository from your main project files.
That's it. You have one file tree, from one repository, but many projects can share it, and if you perform an SCM operation on the source in one project it's reflected in others.
Ideally you would be able to make a dynamically linked shared library (or "framework" in Apple parlance) from the common code, but the iPhone platform does not support this. In addition to the approaches already suggested here, you can link against your own static libraries.
Building static libraries with the iPhone SDK
Easy, Modular Code Sharing Across iPhone Apps: Static Libraries and Cross-Project References
Keep the common code in a common repository. Then you can easily use it in as many projects as you want.