使用 Swift 构建 Cocoapod 并依赖于 Objective-C 框架

Question

I know there are already a few questions on this theme here on SO, but very few have accepted answers, and I don't think I have found the exact same problem as mine.

I'm building a Swift pod, and in my code I rely on the Google Maps iOS SDK, which is bundled as a .framework file. The project builds OK in Xcode, however I have troubles publishing the lib to Cocoapods.

I managed to have a Podspec file that almost validates using the pod lib lint command. However, now that I've added the Google-Maps-iOS-SDK pod as a dependency in the Podspec file, it fails with the following message:

$ pod lib lint

[!] The 'Pods' target has transitive dependencies that include static binaries: (/private/var/folders/n2/qyjfpk6n7zz_mngtwswlmsy00000gn/T/CocoaPods/Lint/Pods/Google-Maps-iOS-SDK/GoogleMaps.framework)

$

Is this expected? Why can't I add the Google Maps iOS SDK as a pod reference in my own Swift-based pod?

Here's the Podspec :

Pod::Spec.new do |s|
    s.name                  = '(name)'
    s.version               = '1.0.0'
    s.summary               = '(summary)'
    s.platforms             = { :ios => '8.0', :osx => '10.10' }
    s.ios.deployment_target = '8.0'
    s.osx.deployment_target = '10.10'
    s.license               = { :type => 'BSD', :file => 'LICENSE' }
    s.source_files          = 'Sources/*.{h,swift}', '*.framework'
    s.source                = { :git => "https://github.com/(Github repo).git", :tag => "1.0.0" }
    s.requires_arc          = true
    s.frameworks            = "Foundation", "CoreLocation"
    s.author                = { 'Romain L' => '(email)' }
    s.dependency 'Google-Maps-iOS-SDK'
end

If I don't include the Google Maps iOS SDK as a dependency, then pod lib lint fails in the Bridging Header, and complains it cannot find <GoogleMaps/GoogleMaps.h> (file not found).

I'm stuck, and I don't know if it's a bug from Cocoapods 0.36 (still in Beta) or if I'm doing something wrong.

Thanks for your help!

Answer 1

I finally found another thread on SO dealing with similar problems: Linker errors in a Swift project with Google Maps for iOS added via CocoaPods .

It appears that the errors were due to a combination of bad Podspec file (on the Google Maps iOS SDK side), and bugs in Cocoapods 0.36 Beta.

It's actually possible to workaround the issues by using @fz.'s revised Podspec file for Google Maps: https://stackoverflow.com/a/28471830/145997 . Another article that also was of great interest to understand how the vendored_frameworks setting works in Podspec is: http://codereaper.com/blog/2014/creating-a-pod-with-crashreporter/ .

So, to correctly import the Google Maps iOS SDK in a Pod project, first use the following Podfile :

source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '8.0'
# altered version of Google's Podspec
pod 'Google-Maps-iOS-SDK', :podspec => "https://raw.githubusercontent.com/Reflejo/GoogleMapsPodspec/master/Google-Maps-iOS-SDK.podspec.json"
use_frameworks! # don't forget this!

I'm now able to reference Google Maps classes from my Swift code simply by doing import GoogleMaps . And, to distribute the Pod, my final Podspec now resembles the following:

Pod::Spec.new do |s|
    s.name                  = 'MyPod'
    s.version               = '1.0.0'

    s.homepage              = "https://github.com/..."
    s.summary               = '(pod summary)'
    #s.screenshot            = ""

    s.author                = { 'Romain L' => '(email)' }
    s.license               = { :type => 'BSD', :file => 'LICENSE' }
    s.social_media_url      = "https://twitter.com/_RomainL"
    s.platforms             = { :ios => '8.0' }
    s.ios.deployment_target = '8.0'

    s.source_files          = 'MyCode/*.{h,swift}'
    s.module_name           = 'MyPod'
    s.source                = { :git => "https://github.com/....git", :tag => "1.0.0" }
    s.requires_arc          = true
    s.libraries             = "c++", "icucore", "z" # required for GoogleMaps.framework
    s.frameworks            = "AVFoundation", "CoreData", "CoreLocation", "CoreText", "Foundation", "GLKit", "ImageIO", "OpenGLES", "QuartzCore", "SystemConfiguration", "GoogleMaps" # required for GoogleMaps.framework
    s.vendored_frameworks   = "Dependencies/GoogleMaps.framework" # Put the Google-provided framework in that subfolder of your Pod project
    #s.dependency              'Google-Maps-iOS-SDK' # Careful! this will cause errors if enabled!
end

I am now able to start a new iOS app in Xcode and use the following Podfile to link against my own pod, itself referencing the Google Maps iOS SDK:

source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '8.0'
pod 'MyPod'
use_frameworks! # do not forget this!

Not that easy, but feasible after all! Hoping Google will soon patch its Podspec file for Swift developments, though.