I have 2 projects and I want to use in the first project, a class (i.e. view controller) of the second. Instead of importing all the files of the second project in the first one, is there a way to link it like a framework or library?
I tried the following unsuccessfully:
Dragged-dropped SecondProject.xcodeproj and checked SecondProject.app as a target
Added it as a dependency project in the first project dependencies
Pointed to the header files by adding in the "Header Search Paths" a path pointing to the second project which I copied in a subfolder of the first project.
When I include "SecondProjectViewController.h" I get no errors but when I try to instantiate it I get the "OBJ C referenced from" error.
Any help is deeply needed and appreciated! =)
F.
As an experienced developer I would suggest not sharing code this way across projects. The simple reason is that changes in one project will then directly effect other projects, often rendering them un-compilable. For example, if you share a controller class and decide to implement a change with a new import, then any project that uses that class will be broken until you open then in xcode and ensure that the imported class is available.
A better method is to compile your first project as a static library or framework. I'd also recommend ensuring that it is version some way. For example, in my projects I create static frameworks and store them in a directory called "v0.0.1", "v0.0.2" etc.
The framework can then be dragged and dropped into a second project to use it. The second project then refers to it via the directory path. The advantage of doing this is that if I then change the first project, the second one if not effected by the changes until I choose to update the frameworks path.
Sharing files between projects will work for small cases, that being 2 or 4 projects, but once you have more than that it rapidly becomes un-manageable.
You have only a few steps to go:
4) in First project, click the disclosure triangle in the Groups and Files section for the Second Project reference. this will display the targets of Second Project.
5) Drag the target reference (e.g., static library) from Second Project to the target in First Project's link phase.
That should clear up all the linker errors for the symbols which exist in Second Project's library. Of course, you'll have to remove those sources (based in second Second) which are compiled and linked from First.
Managing static libraries for huge codebases is dead easy this way (although I prefer the build up to the minute (as well as several build variants), and don't reference archived binaries as Derek does). Learning to minimize changes which break builds takes time to learn. dynamic libraries are a bit different - depending on their distribution, you may want to version (as Derek outlined). It's good to share, but you should put the shared exported symbols in a library, which is a dependency of both apps. Just be careful not to add too much unnecessary objc symbols to the library - objc symbols and their references cannot be stripped from the final executable and they will cause runtime collisions if they appear in two images (dylib, app, static lib) within the same process.
You can add the view controller's files to your 1st project regardless of where they are on disk -- the project will make a reference to their location.
Related
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.
I'm really struggling to get this to work in xcode 4.
I have one project that I will reuse in many applications (networking) so I create a workspace and add my two projects. So far so good....
This is where it fails..
#import "JSONRequest.h"
For no apparent reason. It auto completes the file name of the header file. I thought this had something to do with the "scheme" (also new in xcode 4) so I've tried to add my networking target in the build phase. Changing order of them... set "Shared" under Manage schemes.. I've tried so many different combinations of the settings without any success.. And the error message is get is:
JSONRequest.h: No such file or directory
If you have a clue, please let me know.
You can add the header or source folder of your project you're referencing to your Header Search Paths.
Click on the target that's importing JSONRequest.h.
Click on Build Settings.
Enter "Header Search Paths" into the search box.
Double click on the value cell.
Click the + sign.
Set the path to the project you're referring. Let's say it's called JSONlib. The path is relative to the root of the referring project (the project that's using JSONlib). For example: ../JSONlib/src/headers/ or wherever it is that the .h file lives.
Click done.
Clean and then build.
You'll find more info about this problem in the apple developer forums. Best of luck.
What are you really trying to do?
If you have an entire Xcode project you intend to share between different products that usually suggests your project builds one or more targets (such as a framework, etc.). Therefore, your "shared" project should be able to build the framework on its own, irrespective of the workspace it's contained in, right?
Let's assume it's a framework. In most cases, Xcode can figure out the dependency by simply adding the framework product to the Link build phase of the (assumed) app using the framework. Done. Xcode should know to build the framework project's target first, since it's linked against when building the app project's target.
So your problem is likely just a matter of knowing where Xcode is looking to find files. Since projects within workspaces share that workspace's build folder, they can all "see" each other. But in the case of a framework, A simple import by file name won't cut it. You'd need:
#import <MyNetworkingFramework/MyNetworkingFramework.h>
Since you're including a specific header (JSONRequest.h) (which must be one of the public headers in the framework target's copy headers build phase), you'd need:
#import <MyNetworkingFramework/JSONRequest.h>
If your "shared" project is not a framework, you'll need to amend your question to include a more thorough description of your two projects and their targets.
This worked for me,
In build settings --> Header Search Path --> Add below entry
$(SRCROOT) and mark it as recursive. If above not worked you can also try following way, <path-of-other-project> and mark it as recursive. Hope this helps to you ! (You may require to clean or restart the workspace)
I have two apps which share a lot of source, so I want to put them into one Xcode project and use Targets to build them seperately. Some of the source files have the same name in both projects (for example, MapViewController.h and MapViewController.m). I thought as an intermediate step, I'd just put the whole classes folder into the merged project (with a different folder name) and use Targets to specify which classes folder to use, then later I'd properly merge what I could into common source files.
The problem I found is that I can't include .h files in a Target (the option is greyed out). Do I need to use the same interface file for both Targets and have two versions of the implementation files. Is there a better way to do this? Thanks.
If your going to have two apps with similar naming conventions, with shared code... I'd recommend using the following approach.
Create 3 Xcode projects.
Project 1: Core Code (shared code,
resources)
Project 2: App 1 (import Project 1
and create a dependency on it)
Project 3: App 2 (import Project 1
and create a dependency on it)
Now, every time you change Project 1, both your other projects will be affected.
I've created a project the way you want to right now... And in the long run i've greatly regretted it.
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.
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.