How to import and use Swift Pod Framework in Objective-C Project

Question

I've been trying to checkout CocoaPods new framework setup to get some Pods going and I'm having trouble using the Swift one's in my Objective-C project.

First things first, this is CocoaPods prerelease 0.35, you can read about how to use and install it here.

Here's my current Podfile:

source 'https://github.com/CocoaPods/Specs.git'

platform :ios, '8.0'

pod 'MBProgressHUD'
pod 'SLPagingViewSwift'

MBProgressHUD is a common spinning indicator, and SLPagingViewSwift is a random project I found by typing Swift into the cocoapods search. Here's the ViewController.m In my project:

#import "ViewController.h"

@import SLPagingViewSwift;
@import MBProgressHUD;

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    
    // Works just fine
    MBProgressHUD *hud = [[MBProgressHUD alloc] initWithView:self.view];
    [self.view addSubview:hud];
    [hud show:YES];

    // Causes Error -- Won't build
    SLPagingViewSwift *sl = [[SLPagingViewSwift alloc] init];
}

@end

Here's the SLPagingViewSwift declaration:

class SLPagingViewSwift: UIViewController, UIScrollViewDelegate {

As you can see, it inherits from UIViewController, so it shouldn't be a problem to just allocate it and initialize it. If I add the file separately as just a file, the above code runs just fine. I know it works.

tl;dr

How can I use a pure Swift Framework created by CocoaPods in a pure Objective-C class?

TroubleShooting

Mostly I've been trying various imports. Apple recommends the @import style here

enter image description here

But I have been trying multiple other varieties:

// Compiler Error
#import <SLPagingViewSwift/SLPagingViewSwift.h>

// Builds Fine -- Doesn't Work
#import <SLPagingViewSwift/SLPagingViewSwift-Swift.h>
#import "SLPagingViewSwift-Swift.h"

I've also been trying a few other Swift libraries from time to time to see if I could make anything click.

I don't see anything on the Cocoapods issues that can help this, I also didn't find anything in their blog / release stuff.

Note

If I add the SLPagingViewSwift.swift file separately to the project the old fashioned way, it works just fine.

From what I understand, you can always go from Objc to Swift, but not always the other way around since Swift has language features that simply don't exist in Objc... — user1971598
– user1971598, Commented Jan 17, 2015 at 2:52
@EdgarAroutiounian - You are correct in some respects, but with this type of class, it shouldn't be a problem because it inherits from an ObjC class. Also if I add just the file, my above snippet builds and runs fine. (see update) — Logan
– Logan, Commented Jan 17, 2015 at 2:54
Hey your question actually helped me a lot, I was trying to add FacebookSDK with cocoa pods, and got errors when trying to compile, "import FacebookSDK" did the trick — Michal Gumny
– Michal Gumny, Commented Feb 17, 2015 at 11:10
This question is actually very helpful: using @import in Objective-C -- which many of us have seen never or rarely, is new, helpful and necessary. Thanks for figuring this out. — Dan Rosenstark
– Dan Rosenstark, Commented Feb 4, 2016 at 4:58

Carlos Compean · Accepted Answer · 2015-01-20 05:19:47Z

50

+50

I think you have to declare the swift class as public, otherwise it is treated as an internal class and can be only be seen within the same module, and this could be the reason why adding it to the same project as files work, but as a framework doesn't. Other thing that occurs to me is that the framework may need to add @objc in front of the class declaration so that it can be seen within objective-c classes. Also reading Apple's guide of Mix and Match between objective c and swift it says that when you import an external framework, you need to make sure the Defines Module build setting for the framework you’re importing is set to Yes. Have you checked with any of those options?

answered Jan 20, 2015 at 5:19

Carlos Compean

6846 silver badges6 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Logan Over a year ago

Public did it! Don't know why that had to be that way, but it did. It was my understanding that public was the default, glad to know I'm wrong. I guess that wins you the bounty (in 3 hrs), congrats :)

Edward Over a year ago

Ok, I know this a over a year late, but I feel obligated to answer this (because nobody else did). Swift defaults to internal (only accessible by the assigned group) for many reasons.

Swaroop S Over a year ago

If using a pod using swift framework inside a Objective C project, you need to just add #import "<FrameworkName>-Swift.h". In my case I needed to use Alamofire in my objective C project, so I used #import "Alamofire-Swift.h" to make it work..

Motti Shneor Over a year ago

in my case - the 'pod' is a swift-based framework, and its 'public' classes just don't get exported, and don't appear in the generated <framework/framework-swift.h> header. What now?

Jordi Puigdellívol · Accepted Answer · 2019-10-10 14:24:37Z

14

Jus use the

@import SwiftModuleName;

Syntax, and make sure the functions you want to use are public (and @objc)

answered Oct 10, 2019 at 14:24

Jordi Puigdellívol

1,7583 gold badges23 silver badges33 bronze badges

Comments

Szuwar_Jr · Accepted Answer · 2020-03-03 19:27:58Z

-2

In my case there was no “use_frameworks!” into podfile (old project).

I added it and then I was able to use import like that

#import "PODNAME-Swift.h"

and use classes from pod.

But finally I wasn't able to use that swift pod, because of lack objective c exposition. I believe this will be the issue in many cases.

answered Mar 3, 2020 at 19:27

Szuwar_Jr

7139 silver badges11 bronze badges

Collectives™ on Stack Overflow

How to import and use Swift Pod Framework in Objective-C Project

3 Answers 3

4 Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

4 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related