iOS Declare with local framework

Targets iOS
1

This is the first time I’m writing my own declares on iOS.
If the framework is not in the system (like all the examples I can find out there) how to I reference the path?

2

I think the lib will need to use the special “@executable_path” string in order to specify the location. I haven’t used it on iOS, but that’s what you do on MacOS.

3

Ah, I should have known that.
Thanks, Jason.

4

Make sure the lib is copied to the Frameworks folder using a copy files build step.

You can then reference it like this:

Soft Declare Function myFunctionName Lib "@executable_path/Frameworks/LibName" () As Integer
1 Like
5

That’s what I was looking for. Thanks.
Now the issue is, as I dig in, I will not be able to access this framework via declares because it is setup with classes not just function calls.
Frustrated.

6

to access the classes inside you’ll probably need to load the framework. Here’s a method that’ll help you with that:

Public Sub LoadFramework(FrameworkNameOrPath as String)
  Declare Function dlopen Lib "/usr/lib/libSystem.dylib" (name As CString, flags As Int32) As Ptr
  
  Dim flags As Integer = 8
  
  // If the user just passed the name of a framework to load, look in the system frameworks directory
  If FrameworkNameOrPath.IndexOf("/") = -1 Then
    FrameworkNameOrPath = FrameworkNameOrPath.Replace(".framework", "")
    FrameworkNameOrPath = "/System/Library/Frameworks/" + FrameworkNameOrPath + ".framework/" + FrameworkNameOrPath
    flags = 5
  End If
  
  // Only load the framework if it hasn't been before
  Static LoadedLibraries() As String
  If LoadedLibraries.IndexOf(FrameworkNameOrPath) = -1 Then
    Call dlopen(FrameworkNameOrPath, flags)
    LoadedLibraries.Append FrameworkNameOrPath
  End If
  
End Sub
1 Like
7

In case the framework does not load, which happened to me a couple times, this code can help:

Public Sub LoadFramework(FrameworkNameOrPath as String)
  Declare Function dlopen Lib "/usr/lib/libSystem.dylib" (name As CString, flags As Int32) As Ptr
  
  Dim flags As Integer = 8
  
  // If the user just passed the name of a framework to load, look in the system frameworks directory
  If FrameworkNameOrPath.IndexOf("/") = -1 Then
    FrameworkNameOrPath = FrameworkNameOrPath.Replace(".framework", "")
    FrameworkNameOrPath = "/System/Library/Frameworks/" + FrameworkNameOrPath + ".framework/" + FrameworkNameOrPath
    flags = 5
  End If
  
  // Only load the framework if it hasn't been before
  Static LoadedLibraries() As String
  If LoadedLibraries.IndexOf(FrameworkNameOrPath) = -1 Then
    Dim result as Ptr = dlopen(FrameworkNameOrPath, flags)
    If result = Nil Then
  		Dim reason As String
  		Declare Function dlerror Lib "/usr/lib/libSystem.dylib" As CString
  		reason = dlerror
  		break
  	Else
    	LoadedLibraries.Append FrameworkNameOrPath
    End if
  End If
  
End Sub
8

Wouldn’t you usually use CFBundle or NSBundle APIs from Apple for that instead of lower level dlopen()?

9

All,

I’m confused. I always believed that if the framework had classes that I’d have to make a plugin.
Am I wrong?

10

Depends on the library.
If anything touches threads or is time critical, a plugin may be required.

See also More than just a wrapper

11

Yeah, I fully expect this needs a plugin.

12

Not necessarily. Declares can create instances of classes using NSClassFromString, alloc and init.