I've got an iOS dynamic framework written in Swift and would like to know what ways I can "export" the framework for use in external projects, while leaving the implementation unexposed.
The "best" solution I've come across so far is from this article, but for some reason autocompletion stops working when I'm trying to use classes from the framework in a project.
Right now I'm using a Xcode workspace to use the framework within a project. However, as mentioned I don't want to have the implementation exposed.
I understand that Swift doesn't have separate interface and implementation files found in Objective-C, but am just curious as to how other people approach this.
Related
I want to import a Swift framework called "Beethoven" into Objective-C project. I import this framework via cocoapods.
The problem is that framework is written in pure swift. Since the classes are not subclass of NSObject they can't be used directly in my objC classes.
I am newbie in Swift and intermediate in objC, but I think there may be 2 solutions for that:
1-Modifying the whole library: which is probably not an optimal solution.
2-Using a new class which behaves as an interface between swift framework and my objC code. I think second solution will be a better alternative in terms of time and effort needed.
Actually below given post explains modifying the pure swift classes but I don't know how to apply this in my case.
How to use Swift non-NSObject subclass in Objective-C
As I mentioned I am not a very capable programmer and there may be better solutions for that problem. I would be grateful if someone can help me and suggest the best solution for integrating pure Swift framework into my objC project.
NSObject is usually not the only problem. Swift has many features that are not supported by Objective-C. To name a few: swift value types (struct's), swift enums with attached values. If a library uses any of those, it will not be possible to auto-generate an Objective-C header (.h) for it.
Adapting the code of the library on the spot might work, but it is likely more work long term in case if you ever need to update that library again.
Your 2nd approach sounds better: create a layer that is compatible with Objective-C on top of the library which exports methods that need to be exported with #objc and adapts the types. If you go that way consider making a PR contribution to the original library so that everyone could use it in Objective-C projects, and you share responsibility of updating it when the swift code changes.
The 3rd approach would be actually to rewrite some parts of you app to Swift. That might or might not be easier depending on the size of the part of the app that is using the library and how well it is isolated from the rest of the app.
My goal is to build a swift iOS framework which uses two other frameworks (included as separate projects) and which shouldn't reveal the source code after built.
Is there some text/guide/documentation which would explain and navigate me through the process of building such a framework properly and correctly?
I built framework with aggregate target adding and linking frameworks on which my custom framework is dependent using run script as indicated here. I was able to add built of my custom framework to my custom app, together with other two dependencies (again as a separate projects), and run it on the device. However, I am not convinced by the correctness of my custom framework built.
Moreover, I was not able to upload the archive to the Appstore due to the various errors of "Unsupported architectures...", "CFBundleIdentifier Collision...", "Invalid Bundle...", "Invalid Binary" and so on. After sorting these errors out according to the various stackoverflow answers and installing the app from the TestFlight, the app crashed after launch and wasn't working at all.
I was checking various blog posts, stackoverflow questions/answers and Apple Framework Programming Guide but nothing gave me comprehensive understanding on building custom framework under conditions described above.
Everything I did was just following step-by-step tutorials without explanation of the purpose of the steps. I am sure I am missing the basics. Could you please help me and give me some guides?
I can understand you frustration. I, a while ago too searched probably for many documents on how to write a framework correctly but like you I also didn't find anything really that satisfying. From my own experiences I can give a couple of advices.
NO External Libraries
In my opinion DO NOT use external libraries in your own framework. I don't really know what your frameworks purpose is but most of the stuff you want to do can be done without using external libraries. Depending on other libraries is not a good idea especially if its a framework you are working on. Anytime these libraries get updated or even worse if they don't you will have to wait for them to be updated or find another library.So rather than this happening later on I think its better if you do it from the start. So loose the external libraries.
Universal Framework Binary
Second one is pretty easy. Generating a universal framework. I suggest you don't use a script. Most of the scripts I found were either outdated or they didn't work at all. Later on I found out that actually it was pretty easy to generate one on your own. You can do this by building your project once for a real device and one for the simulator.Then you can generate a universal binary by using the command lipo -create "Your simulator executable path" "your iOS device executable path" -output "your framework name". What this does is that it combines your two executable files and generates a universal one. Then you can just go and copy your simulator documents from the modules file and paste them in you iphoneos modules file. I am going to share a link were you can go through the walkthrough yourself. https://medium.com/wireless-registry-engineering/create-a-universal-fat-swift-framework-b7409bbfa18f
Use Objective-C(If you can)
This one is bit of a tricky one unless you know objective-c. What I would recommend is that you implement your framework using Objective-C and writing a swift wrapper around it. I would not have said this if you were creating an iOS app but in case of a framework I still think you should go for objective-c. This is because Objective-c has been around for over 30 years and most of the very old apps are in objective-c. If you want your framework to easily be used by older apps coded in objective-c I recommend you go with it. I have read tons of posts on how people have problems trying to use frameworks written in swift in their objective-c apps. Swift will be the first and probably only choice in the near future but not just yet. On the plus side if you still haven't you will have learnt Objective-C which will give definitely give you a better understanding on how things work. It will be challenging but I promise you it will be worth your while .I have a good read on this which you can checkout yourself. https://academy.realm.io/posts/altconf-conrad-kramer-writing-iOS-sdk/
Naming Conventions
This is a pretty straight forward one. I suggest you stick to apples naming conventions. This is because you will be sharing your code this time and people will look for familiarity when trying to integrate your framework. This will make your code easier to understand. You can check out these two links for more info.https://github.com/raywenderlich/objective-c-style-guide (obj-c) https://github.com/raywenderlich/swift-style-guide (swift)
Access Control
This in my opinion is an important one. When working on you framework think before you implement a class or a function. Consider if you would like someone else to be able to use that part of your code. You may want to limit the user while they use your framework and correct access control is the way to do it. You can easily guide the users so the users do exactly what you want them to do with your framework.
Document Your Code
This is a must if you want your framework be a professional one. You should be documenting every function and variable the user will use. Documenting and explaining what your code does makes a lot of peoples lives easy. You don't one anyone trying to understand what your code does for half an hour while you could have easily written a small explanation for what the parameters do and one that function or variable should be used for.
Test Your Code
Last but not least do write tests for your code. This does take some time but it assures you that your code works the way it should.
Look at other good frameworks
You should definitely checkout other open source libraries and look at what they have done. Usually there is no point in reinventing the wheel unless you are doing something absolutely different but even then there are very familiar ways to do things. I can suggest you check out the mantle sdk(https://github.com/Mantle/Mantle). Another one is the very popular Alamofire sdk(https://github.com/Alamofire/Alamofire) and also the Realm sdk(https://github.com/realm/realm-cocoa). These are good examples of frameworks. Take a look at them. Look how they have done things. It will give you an insight on how your framework should look like.
I know all of these points may also be valid if you were writing an app but what makes these a must is the fact that you will be sharing your code with others. You may manage by not doing some of these while implementing an app but for a framework things do change a little bit. It is always a pleasure to work with easy to use frameworks which make coding a pleasure. These types of small things will make your framework preferable. Happy coding.
I think I just must be stupid.
I'm having a lot trouble understanding very basic things concerning frameworks in Xcode/iOs/Swift. While I've certainly gotten some things to work, I've gotten more and more confused about what I'm actually doing. And the documentation on the web just confuses me more.
When I see discussions about how to import particular frameworks (e.g. https://github.com/danielgindi/Charts is the library I'm playing with, but I've seen this pattern repeated in other libraries) they seem to always tell me include the Xcode project file as a child project of my project, in addition to linking things as an embedded binary. This confuses me. Is it not possible to link an already compiled framework to my project without including all the source code of the project?
That is, can't I just take a library.framework file, and add it to my embedded libraries list and be done with it?
In the frameworks I've played with (again https://github.com/danielgindi/Charts is my primary example, but this is true in many others I've played with) I can't seem to use the framework without Carthage or CocoaPods. For me at this stage, that is just confusing... I accept that they are useful tools to automate a difficult process, but I'd really like to understand what that process actually is before I let a tool automate it for me. As I search the web I just seem to always be led back to these tools as being the correct way to do things.
So here are my questions.
If I find a framework library on the web... do I need its source code or can I somehow just link to a compiled version of the framework?
In my reading, it seems that libraries made with Swift are somehow second-class citizens because Swift is a newer thing. Is that still the case? (The articles I read about this seems to date from 2014-2015).
Is there are good place to understand how Apple expects me to add a framework to a project, without using CocoaPods or Carthage?
No need to add source code. Just add the framework to Target ->
General -> Linked Framework and Libraries -> Tap on + and select
your framework.
In my opinion, many new libraries are being written is Swift. So you won't be left behind for using swift.
Apple has documentation about adding frameworks to XCode. But I would suggest to use Cocoapods , as its easy to manage libraries.
Cheers :)
I am building a new framework. The project is to be coded into Swift language, however the clients using this framework have the freedom of using either swift or Objective-C framework.
The question is how do I start. There could be numerous issues like
using structs in swift code but it cannot be made available in
objective C framework.
optionals are missing objective c
Even if I
write different set of files for Swift and Objective C, how will I
map them onto different frameworks under the same project.
Enums with other than Int as rawValue can't be used.
Tuples would not work
I know there have been a few questions around this but none have any satisfactory answer.
PS - Any link to a tutorial or blog would be super helpful too
I did this and got some unexpected results: I have trouble integrating the framework in Swift application. Objective-C works just fine.
You mentioned some of the caveats here.
I suggest doing this iteratively while writing test application in Objective-C which uses all the features. This way if there is some feature that does not cross Swift to Objective-C boundary well, it will be discovered as early as possible.
Your remarks about issues are generally correct with one small exception: optionals are not missing from Objective-C, they appear as nullable/nonnull modifiers on variables and method parameters. Although this does not replace optionals fully, it helps detecting issues early in the process.
Here is a random list of some other issues I discovered:
Bridging between Swift Error and NSError used in Objective-C. The conversion is not always as smooth at it could be, so better use NSError in exported code.
If you mix Objective-C and Swift in your framework, you cannot use bridging header, instead using modulemap files which tend to turn pretty large and complex.
Since you cannot embed frameworks inside a framework, you have to make sure that the application sets ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES flag for its target. This has to be clearly indicated in the documentation. Also, when creating fat library for your framework, you have to strip these files from the distributed SDK.
And, as I said in the beginning, I still have no success using the resulting mixed language framework in Swift application.
Hope, this will add to your list of things to take into account when developing the library.
I am trying to build an iOS swift framework to display encrypted photos. Photos are sent by my server (something like a hashed binary file) after calling a specific API with specific details. I will then decrypt the photo, and display it to the user.
Correct and point me in the right direction if I am wrong, but swift only allows frameworks - meaning no static library. And this will expose my implementation details (such as the method to decrypt my photo).
What I would like to achieve is to create a cocoapod distributable framework for paid developers to implement (once they subscribe to me). It is supposed to expose simple public APIs, and hide implementation details.
I have tried various ways to achieve that but to no avail. I would really like to keep the implementation to swift codes only, with minimal Obj-C codes.
Build a swift framework, and build an objective-c static library as a wrapper
But I cannot seem to get it to work. Any idea if this is possible?
Build a swift framework in a swift framework
Stupid idea, i'm able to see the framework's implementation details within the other framework...
Build a swift framework, and build an objective-c framework as a wrapper
I cannot seem to get this to work either...
I have been working on this project for about 2 weeks now, and have been all over Googling for it. Just in case anybody would like to try, you may try to do the following and check if it works.
Cocoapods Friendly Framework
Implementation Details Hidden
Uses Alamofire (or any public framework that connects to internet)
Any help would be appreciated, thanks!