How to add existing Library to my iPhone project - iphone

So, Not a very sophisticated question, but since I never did it before I need your advice.
I have my main project, which includes 2 more sub projects that produces static libraries that the main project uses.
Now, I want to add a Loggin framework to my project, and I want to be able to use it inside my main project and inside my static libraries as well.
As you can witness here, it's not very hard, only 3 files needs to be included.
However, I'm not sure what's the best way to do it.
Adding those 3 files to each of the projects would probably cause symbols redefinition.
Adding to just one of the static libraries is not enough, unless I make the other one dependent on it, which is not quite correct logically.
I can probably make another static library project from these 3 files, and make my project and my 2 other sub projects dependent on it, but it feels like an overkill.
What's the best course of action here ?
Thanks!

Putting those files in yet another separate library or framework would be my take.
You should perhaps reconsider if you really need your sub projects precompiled in static libraries (what advantage is that providing to you? are they really that huge that recompiling them now and then is that bothersome?).
A single Xcode project with everything on it might be a better solution, and is what I usuallly favor these days. That way you also don't have to worry about missing architectures in your libs or having compiled the lib with a compiler version and the main project with another, bugs within the libs can be debugged and traced more easily, etc…

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iPhone SDK static library versioning

I've been writing iOS apps for some time now and for this particular project, I decided that I needed a static library for code sharing purposes.
I've followed some tutorials in creating static libraries and everything works perfectly.
Now I wonder, is there any way of versioning the static library?
I couldn't find any files regarding version number in the static library project, nor any good search results (both Google and here) regarding this particular issue.
I think I could create some kind of "fake" Info.plist and store the version info there.
Is that the way of doing it? Any other approaches to the problem?
Edit:
I think I may have not been clear on my purpose:
I have a workspace that has both my library project and related projects using the library, which is imported using the .xcodeproj file, then configured the dependencies so it builds whenever needed.
I just need some way of versioning the library, so that I can include that in some sort of about box, just in case.
I think you should stay away from bundling binary builds of your own code. Unless you're building a really, really, really massive library, you're better off just importing the code in any of your projects, and rebuilding it each time. You can put it in a separate target though, so Xcode doesn't rebuild it all the time.
You might want to write a tool that takes version info in a .plist and writes it out as literal strings defined in a .h file, which you can then include in your own code.
To make it foolproof (avoid mismatch between the header and the library), define a class method like [YourLibraryClass versionString] that returns a NSString with the version number or signature.

iPhone static lib

i want to share some code with other iOS projects. So I create static library.
When I use this library in other projects and use header file from that lib I get an error like No such file and Directory. Can any one tell me fixes of it.
Here I get reference for making static lib
http://www.amateurinmotion.com/articles/2009/02/08/creating-a-static-library-for-iphone.html
I downloaded that sample. It is also not working in my case. So please help me to fix that error.
Thanks in advance
My guess would be because the blog, whilst detailed, is probably a bit old now. Like anything there's a thousand ways to skin a cat.
You can now create frameworks for the iPhone sdk and include both simulator and device versions of the classes. Frameworks have the advantage that they can simply be dragged and dropped on Xcode to include them in a project. In addition I like to store my frameworks in version numbered directories so if I make changes, dependent projects can still use the old ones until I'm ready to update them.
I don't do it, but for the above reasons I'm not sure I'd drag and drop a libs project on a client project. To me the idea of a static framework is that it's independent on it's clients. Dropping it into client projects makes a connection between the two projects that is too tight.
Anyway do some searches on lipo and static frameworks. I also have so scripts in my project at https://github.com/drekka/dUsefulStuff that you mint find useful.

XCode: Linking projects inquiry

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.

Considerations for including library as binary vs source

I'm trying to write an SSH client for the iPhone, and I'd like to use the libssh2 open source library to do so. It's written in C.
How should I include this C library for my iPhone app? Should I compile it into some binary that I include into the my app, or do I add all the source to my project and try to compile it along with the rest of my app?
I'm interpretting this question as:
"Should I compile the C library code once, and include the binary library in my project? Or should I include all the source and compile it every time I build my app?"
It depends. One of the projects I work one depends on several external libraries. Basically, we have a simple rule:
Do you think you will need to change code in the C library often?
If you will be changing the code, or updating versions often, include the source and build it with the rest of your project.
If you're not going to change the code often or at all, it might make sense to just include the pre-built binary in your project.
Depending on the size of the library, you may want to set it up as a distinct target in your project, or for even more flexibility, as a sub-project of your main project.
If I was in your place, I would build libssh2 ahead of time and just include the binary library in my iPhone project. I would still keep the libssh2 source around, of course, in case it does need to be re-built down the road.
I have an iPhone app that is 90% c. I have had no problem adding 3rd party sources to my project and compiling. I am using Lua, zLib, and libpng with no modifications. I've also included standard libraries like unistd and libgen and they just work™
The Three20 iPhone library has a great howto on adding their library to your xcode project. Give that a shot.
I think you will find in the long run you will be better off building it into a standalone library and linking it with your application. This makes it easier to integrate into future apps. Another benefit is that it encourages code separation. If you feel pretty confident with the library, you can link your debug exe to the release build of the library and get some extra performance.
I can't really think of any downsides to creating a library, after the initial cost of setting it up, and having an extra project to modify if you have some changes that need to be made to all your projects. Even if you don't know how to make a library for the iPhone, this is a good excuse to learn.
Just adding the source to you project should work fine as well.

Large apps in GWT: one module, or several?

In order to provide nice URLs between parts of our app we split everything up into several modules which are compiled independently. For example, there is a "manager" portion and an "editor" portion. The editor launches in a new window. By doing this we can link to the editor directly:
/com.example.EditorApp?id=1
The EditorApp module just gets the value for id and loads up the document.
The problem with this is ALL of the code which is common between the two modules is duplicated in the output. This includes any static content (graphics), stylesheets, etc.
And another problem is the compile time to generate JavaScript is nearly double because we have some complex code shared between both modules which has to be processed twice.
Has anyone dealt with this? I'm considering scrapping the separate modules and merging it all back into one compile target. The only drawback is the URLs between our "apps" become something like:
/com.example.MainApp?mode=editor&id=1
Every window loads the main module, checks the value of the mode parameter, and and calls the the appropriate module init code.
I have built a few very large applications in GWT, and I find it best to split things up into modules, and move the common code into it's own area, like you've done. The reason in our case was simple, we had some parts of our application that were very different to the rest, so it made sense from a compile size point of view. Our application compiled down to 300kb for the main section, and about 25-40kb for other sections. Had we just put them all in one the user would have been left with a 600kb download, which for us was not acceptable.
It also makes more sense from a design and re-usability point of view to seperate things out as much as possible, as we have since re-used a lot of modules that we built on this project.
Compile time is not something you should generally worry about, because you can actually make it faster if you have seperate modules. We use ant to build our project, and we set it to only compile the GWT that has changed, and during development to only build for one browser, typical compile times on our project are 20 seconds, and we have a lot of code. You can see and example of this here.
One other minor thing: I assume you know that you don't have to use the default GWT paths that it generates? So instead of com.MyPackage.Package you could just put it into a folder with a nice name like 'ui' or something. Once compiled GWT doesn't care where you put it, and is not sensitive to path changes, because it all runs from the same directory.
From my experience building GWT apps, there's a few things to consider when deciding on whether you want multiple modules (with or without entry points), or all in one: download time (Javascript bundle size), compile time, navigation/url, and maintainability/re-usability.
...per download time, code splitting pretty much obviates the need to break into different modules for performance reasons.
...per compile time, even big apps are pretty quick to compile, but it might help breaking things up for huge apps.
...per navigation/url, it can be a pain to navigate from one module to another (assuming different EntryPoints), since each module has it's own client-side state...and navigation isn't seamless across modules.
...per maintainability/re-usability, it can be helpful from an organization/structure perspective to split into separate modules (even if there's only one EntryPoint).
I wrote a blog post about using GWT Modules, in case it helps.
Ok. I really get the sense there really is no "right" answer because projects vary so much. It's very much dependent on the nature of the application.
Our main build is composed of a number of in-house modules and 3rd party modules. They are all managed in seperate projects. That makes sense since they are used in different places.
But having more than one module in a single project designed to operate as one complete application seems to have overcomplicated things. The original reason for the two modules was to keep the URL simple when opening different screens in a new window. Even though had multiple build targets they all use a very large common subset of code (including a custom XML/POJO marshalling library).
About size... for us, one module was 280KB and the other was just over 300KB.
I just got finished merging everything back into one single module. The new combined module is around 380KB. So it's actually a bit less to download since most everyone would use both screens.
Also remember there is perfect caching, so that 380KB should only ever downloaded once, unless the app is changed.