I have just started working in iOS8. I have seen here Playground concept. But I didn't understand it. I have read that it could be only used with the Swift language.
I have referred documents from this link .
Can we use it with Objective-C too?
Thanks for any help!!
The playground concept is built upon a technology called REPL (More info on REPL)
Basically you can type code into the playground which is 'compiled' (evaluated) on the fly so you can see the output/result.
It's quite a nice way to play with a language, design a function or test an algorithm, but you cannot build a distributable app with a playground.
For a playground concept to work a given language needs to support REPL. Currently Objective C does not support this, therefore only Swift is available in playground form.
Related
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.
Actually, I am working on one app and started with the objective-c. Now i have started working on swift with the same app for the further development and it will work with both the class (objc and swift).
Now I have doubt that it will accept by apple store or not.
Please help me.
This is fine, Apple provides the mechanisms for interacting with both and will not drop support for Objective-C for quite sometime. Many large organisations still have the majority of their code written in Obj-C (including Apple) so they need to give people time to transition, they aren't going to switch over immediately to a relatively immature language.
You can use Swift and Objective-c together. There is no issue in it. You need to create a bridging header file.
Please read this
Swift and Objective-C in the Same Project
I am planning to learn to develop iOS apps. I'll most probably be learning Objective-C only for now and would like to develop some actual apps for iOS.
Now, with the launch of Swift 2.0, will Objective-C apps still run on iOS9 ? Also, is it possible to test run an Objective-C app on your phone like mentioned here ? https://developer.apple.com/xcode/
Or is this facility available only for apps written in Swift?
Does Swift allow me to do everything that Objective-C does?
Any further advide or guidance for what should I know before enrolling for the course will be appreciated to help me judge things better.
Swift is still just the second language. All Cocoa frameworks are written in C or Obj-C (maybe the new ones in iOS 9 are written in Swift).
The language in which an application is written doesn't matter, the code is compiled into the same machine code, so yes, Obj-C apps will continue to run and many developers won't bother with Swift. Apps that have been already written will not have to be rewritten to Swift (with some exceptions).
Swift won't allow you to do absolutely everything that Obj-C does but it will allow you to do almost everything and the code will be probably more robust, considering that Swift is more modern language with stronger typing than Obj-C. If you are a beginner, you won't probably find any problematic use case.
I have created an iOS mobile application. Is there a way to generate a UML class diagram for the Swift programming language?
I have tried Omni Graffle, but it keeps saying that the project doesn't contain Objective-C interfaces. And Omni Graffle only does this for Objective-C.
I remember looking at this question a while ago and was disappointed that there wasn't any tool like this so I created one myself with the help of a colleague. It's free, it's open source, it's looking for contributors...
https://github.com/yoshimkd/swift-auto-diagram
And here's a tutorial on how to use it (don't worry it's very simple):
https://martinmitrevski.com/2016/10/12/swift-class-diagrams-and-more/
Happy diagraming :)
The answer unfortunately is: you can't do it. At least not automatically. Swift as compiler itself has enough flaws left. Leave alone some tool will be able to swallow any Swift code. Your only alternative is the good old manual way.
I know that Enterprise Architect has a possibility to define a language syntax based on BNF. But Swift is (again unfortunately) not context free. (In fact it's so context sensitive that it often swallows its own rear.) So that won't work either.
P.S.: Now that Swift is open source someone might take the opportunity to tap the compiler's output for the class interfaces. I guess that should not be too difficult, but it's a lot of work still.
Inspired by swift-auto-diagram and similar open-source tools I started to work on such utility with the goal to write it in Swift (to make contribution easier by Swift developers) and to integrate it in Xcode and the Swift ecosystem.
Xcode extension: https://github.com/MarcoEidinger/SwiftPlantUML-Xcode-Extension
You are able to generate a class diagram from selected lines of code or from a whole file displayed in Xcode. The class diagram will then be opened in your browser. There you can modify the diagram with PlantUML notation
To generate a class diagram from multiple source files you can use the underlying CLI tool and Swift Package: https://github.com/MarcoEidinger/SwiftPlantUML
There is a size limitation to the visible diagram content (but you can delete content in the browser with PlantUML notation)
Hello I have found two links about AVCam
Apple: https://developer.apple.com/library/ios/samplecode/AVCam/History/History.html
alex-chan/AVCamSwift: https://github.com/alex-chan/AVCamSwift
The first link has demo files that work perfectly, but its in Object-C - can someone show me documentation on converting Object-C to Swift?
The second link I have downloaded the files but it will not run in my 4s - can someone tell me why?
I would like to have a swift version so I can easily adopt it into my swift build + thanks again SO!
if you have a working objc version why not just import it with a bridging header? there is no one document about converting obj-c to swift, if you really want to convert it you are going to need to do it line by line.
also what exactly are you trying to do? get a live camera feed displayed? these docs have been ported to swift and would suit that purpose but you would need to get the input port first.
https://developer.apple.com/library/mac/documentation/AVFoundation/Reference/AVCaptureVideoPreviewLayer_Class/index.html#//apple_ref/occ/clm/AVCaptureVideoPreviewLayer/layerWithSession:
Update: how to import obj-c headers, a newer way to create them that isnt quite as talked about yet is to just create any normal .m file or objective c file then select yes to creating a briding header, it configures everything for you.
That being said it may be worth while to play around with the basics a bit more and maybe follow a few guides before attempting to implement this type of feature if you are having issues with following the links.
Here is a random application creation guide http://www.ioscreator.com/tutorials/calculator-tutorial-in-ios8-with-swift that should teach you alot. i would recommend following and reading through stuff like this until you have a bit more of a footing and can come up with more of an exact question. no one here is going to rewrite the apple program for you and your questions are extremely broad.