I'm working in a iOS project that includes a static library created by another company.
The library include an old version of AFNeworking and I don't have any source files.
Now i need to use a more recent (and less bugged) version of afneworking, but i cannot include the same class twice in the project (of course) because all the "duplicate symbols".
I understand that it's impossible replacing the version included in the library, but how can i include another version along the old one?
There is a (easy) way to refactor the entire framework before include in my project?
thanks
You'll have to repackage the static library to remove the embedded AFNetworking files.
Unpack the library with:
$ ar x libwhatever.a
And re-package it, including all files except the AFNetworking object files:
$ ar cr libwhatever.a file1.o ... fileN.o
You will then have to link your executable with the new AFNetworking static library and hope that there haven't been API changes which will break the code in libwhatever.a. If there are then I doubt there is much you can do.
I'm afraid this isn't easy to do. Very few environments allow you to link against two separate versions of the same framework at the same time, and Xcode / iOS is not one of them.
As I see it, you have three options:
1) Link against their library and use the same version of AFNetworking they use.
2) Link against their library, and manually load the newer version of AFNetworking and pull symbols from it. Be warned: this will get ugly fast and future maintainers will wonder what you were smoking.
3) Get them to update their library.
On a side note, I don't know the circumstances here, but in general they should be providing you with sources. It's a very backwards practice to provide only a static (static!) library and no way to know what it's doing inside. You'll have to sign a software license agreement and whatnot to protect their interests.
The best and most proper way of handling this would be to contact the the creator of the static library and get them to resolve the situation. They could resolve it either by updating the embedded version of AFNetworking, removing their dependence on AFNetworking, or adding a prefix for their embedded copy of AFNetworking. The last one is probably a good idea anyway when a third party library embeds a different library, because otherwise it would be impossible to use two libraries simultaneously that both include the same third party library.
You could also refactor the copy of AFNetworking that you include yourself to change the names of classes to have a prefix, although this should be unnecessary, as the static library vendor should have done this themselves already.
Lastly, you could find a different library that accomplishes the same thing as your current one but that doesn't embed AFNetworking.
Related
I am developing an app for IOS,and I have to use some framework.
as you know Cocoa pods and Carthage are dependancy manager for iOS and mac OS
my question is "why we have to use dependancy manager?, instead of using dependancy manager just clone that project[was written by other programmer and can be used as framework] and drag and drop to your project ??"
Thanks for your answers
Few things that you need to think about is:
Updating your dependencies when new versions came out.
Updating dependencies for multiple platforms.
Interdependent frameworks and different framework versions for dependant frameworks.
Basically, time that you will spend on maintaining dependancies for your project will grow as your project grows. Dependancy managers allow you to avoid all this unnecessary and boring work.
There are a lot of other reasons to use DM instead of just importing frameworks. More about you can find here. And here.
At some point you might want to use 3rd party code to get extra features or something, you can copy the source code but how you will update it in the future? keep coping it again!!
Also some of your 3rd party code might depend on other 3rd part code, and if you copied it twice, you will get duplicate symbols.
Dependency managers handle all this for you.
My advice is to use Carthage or submodules, but do not use CocoPods, anything that touches the project file is not a good practice with Apple.
Why Libraries are Your Friend
While you aren’t strictly required to use third-party libraries or
frameworks, they can definitely save you a lot of time and let you
focus on polishing your app instead of typing out countless lines of
code that you simply don’t need to write.
You can use third-party frameworks and libraries without a dependency
manager too, and you can get hands-on tutorials about them right here
on this site. For example, there’s our Alamofire tutorial, and our
SwiftyJSON tutorial.
Without a dependency manager, you simply add each library’s code to
your project manually. However, this approach has several
disadvantages:
Updating a library to a new version can be difficult, especially if several libraries must be updated together because one depends on
another.
Including a library in your project makes it tempting to make local changes to the code, making it harder to update to a newer version
later.
Determining the current versions of libraries used in your app can be hard to do, especially if you don’t proactively keep track of them.
Finding new libraries can be difficult without a central location to see all the available libraries.
CocoaPods helps you overcome all of these issues and more. It fetches library code, resolves dependencies between libraries, helps
you search for and discover new libraries, and even sets up the right
environment to build your project with minimum hassle.
Courtesy
https://www.raywenderlich.com/97014/use-cocoapods-with-swift
This is just an informational question, I have been examining several ways to make frameworks in iOS.
I made
Swift Pure frameworks:- There I got to know that, you have to include the xcodeproject to the application project to use the .framework included in .xocdeproject. So I thought this is not the secure way to giving code to third party and I also I did not find ways to include the third party frameworks to my own framework.
Objective Static Libraries:-
In this type libraries, the system is generated a .a file which is secure and the person gonna use does not know the implementation part however found out that if I want to include a third party framework to this, I will have to ask the end user to include that third party project to end application to compile it which will show the end user what all dependancies I have, which I don't want.
My issue is I wan to make a Framework which will consist of all the third party frameworks however, they would be hidden from end user although the codes from them can still be used by end user as required however, end user should not see them listing in my framework.
Is there a way out?
I have gone through many links and found out that many have this doubt as well
Like
Adding FacebookSDK.framework into my own Static library
In this post, one person is asked to get all header files and the framework file and then add that to static libraries to build to add the framework itself, I tried that too without success.
Do not do that.
There is literally no good outcome of what you're trying to do. This is very confusing and couples your library API with a different library's API, forcing the user to stick with your version of the 3rd party lib.
If the user will want to use a newer version of the 3rd party dependency, he won't be able to, because it will result in duplicate symbols.
You can't find any information about such practice on the internet, because nobody does this.
If you want to distribute an already compiled library, there's no other way than just compile all 3rd party code with it, without exposing the header files.
There's one very big important thing left: you have to make sure that users of your SDK will not end up with duplicate symbols if they also use the 3rd party library!
More here...
And here...
I want to add add 3rd part library to my library (which will be used by other developers), so if I have for example this class SBJson do I prefix it with my two letter prefix to be EXSBJson also I saw somewhere somebody is using underscore EX_SBJson. What is the naming convention/style in this case?.
There is no general convention, but we have used the following approaches:
Use the same prefix as the library (so if we develop XYFunctionality, we would name it XYSBJson). A lot of source projects use this approach (e.g. Dropbox)
Talk to other devs, if possible. In most cases, it is enough to distribute the library separately from 3rd party libs (so we ship a .a binary file and a working source project of the 3rd party library so other devs can use it). This also allows other devs to upgrade the 3rd party library to get bugfixes as long as there aren't breaking API changes.
Btw. much of what SBJson does can also be done using NSJsonSerialization which comes with iOS 5+
I'm developing an iOS SDK that integrates other SDKs (Facebook SDK 3.5, for example).
To prevent collisions and allow my customers to import those SDKs as well, I want to rename all of the classes/enums in my code (for example, rename FBSession to RDFBSession, etc).
Is there an easy way to do this instead of going class-by-class and using Xcode's rename feature?
Apple provide a command-line tool called tops(1) that is designed for scripting large-scale code refactoring (renaming C functions, Objective-C methods, classes, and other tokens):
tops -verbose replace "FBSession" with "RDFBSession" Sources/*.[hm]
If you have a lot of replacements, you can put all of the replace... commands into a file that you pass with the -scriptfile option. The man page has more information on the more complex commands/options (and examples).
Xcode also offers textual Search and Replace. This will be faster than individual refactors, but it is ultimately less automated. You can make the step by step refactoring faster by first minimizing the project to the relevant dependencies/sources (if possible).
However, renaming the declarations in a library will not alter the symbol names of its associated binary. If it is distributed with a binary, then renaming will just result in linker errors or (in some cases) runtime errors.
The best idea if you need to use a 3rd party library which your clients might also use is to simply inform them they need to link the library with their app, then publish the version(s) the current release supports so they know they have some extra testing if they go too far ahead with some libraries.
I think that a better approach than simply renaming your classes would be to download Facebook's open source code, rename the classes there and compile a new static library with a set of renamed header files. Then you can be sure that no collisions occur and that you're using symbols that you named yourself.
I must warn you though - working like this may make updating the SDK a nightmare regardless of how you tackle this specific issue.
I am writing an iOS library which depends on some other open-source libraries. Apparently it is not possible to have two classes with the same name, so it is possible that the library compiles, and a project that potentially could use it compiles as well, but they do not work well together (at the linking phase).
The library is targeted at a large audience, so I can not make any assumptions on whether these developers will be importing the same libraries or not, or if they might be using a different, incompatible version of the same libraries.
I have been looking around but couldn't find any clear solution to my problem (maybe there isn't). So far I am thinking of these options:
Inform the users that X libraries are already included in the project, so they do not include them as well. This means they can not use a different version of X libraries.
As a refined version of the first one, use CocoaPods, so dependencies are resolved automatically. Still has the disadvantage that two versions of the library can not coexist.
Import and rename all classes my library depends on, prefixing them, so the names don't conflict with the original ones. This is tedious work, but more importantly, has the disadvantage that I would not be able to pull/push code from/to the original library, as the code would change too much. Still seems to me the best option from the user perspective.
Can you think of a better idea? I'm pretty new to library projects, so maybe there is something obvious I am missing.
We're still not decided whether to distribute in binary or source code form. If there is a reason to choose one or another I would also like to hear your opinion.
When I was faced with this problem I choose your third option and prefixed the dependent classes within my library. The reason you might want to consider doing this rather than relying on the user to import the others would be that you can guarantee compatibility and you don't have to worry about versions of who you depend on.
First point -
Inform the users that X libraries are already included in the project,
so they do not include them as well
so you have a static library Foolib.a, it has a 3rd party dependency Barlib.a, in order for Foolib to build, Foolib's HEADER_SEARCH_PATHS must be set to the path of Barlib's public headers. No more.
If you are distributing your source code you can use CocoaPods (this is a good way to go), or you can add Barlib's repository as a git submodule (or whatever for your choice of VCS) of your repository and hard code the HEADER_SEARCH_PATHS to that path, or you can require that your user grabs their own Barlib and manually edits HEADER_SEARCH_PATHS to the correct path (if you go the CocoaPods or submodule route the user can easily do this as well, so has more options).
Nothing from Barlib is 'in' your project.
On the other hand, if you are distributing a binary for your user to link into their app you must specify in your instructions that Foolib requires Barlib to be linked into the app. Instructions for how to get hold of Barlib would be nice.
Nothing from Barlib is 'in' your project or compiled into your library.
Second Point -
use CocoaPods, so dependencies are resolved automatically. Still has
the disadvantage that two versions of the library can not coexist
Two versions of the same library in one App is impossible, but the situation where the end user already requires Barlib 3.0, wants to use your Foolib, but Foolib requires Barlib 4.0 doesn't have to ever arise - It is up to you the developer. You can be generous and support multiple versions of Barlib (i.e. all Foolib needs to work is a Barlib1.0, Barlib2.0, Barlib3.0 OR Barlib4.0 linked into the app - similar to writing an app that supports iOS5 and iOS6) or, you can be opinionated and require a specific version, and if the user is already requiring a different version of Barlib, tough luck, they will have to change their code if they want to use your library.
Third point -
Import and rename all classes my library depends on, prefixing them,
so the names don't conflict with the original one
This is just too terrible for me to consider at the moment. Sorry.
Nothing from Barlib is ever 'in' your project or compiled into your library. You don't distribute any copy of Barlib - either linked into your binary or as source code.