Why Apple disallows static library in a framework?

Question

it states that:

If you are building your own static library and using shell scripts to package it in a .framework directory, you need to migrate to building a framework with a dynamic library instead, as this is the correct way to build a framework. Static frameworks are not a supported way of sharing static libraries.

Why Apple disallows static library in a framework?

And is it a contraction of this post ? Or maybe that post confuses static library and static framework?

All frameworks in iOS are dynamic, right? Apple said:

A framework is a hierarchical directory that encapsulates a dynamic library, header files, and resources, such as storyboards, image files, and localized strings, into a single package. Apps using frameworks need to embed the framework in the app's bundle.

Right, as the release notes state developer.apple.com/library/archive/releasenotes/DeveloperTools/…, "Xcode supports static library targets which contain Swift code. Debugging applications that use Swift static libraries may require a complete set of build artifacts that are in their original location." — user10607206
It looks like there are some static frameworks, but Apple doesn't have much documentation about it. Like described like here: I haven't seen any word about static framework in the official documents. There is only (dynamic) framework. So xcode cannot handle it well like dynamic framework. Resources in the framework can't be copied to app's main bundle automatically. If you use cocoapods, it will handle it automatically, but not for the manual integration. github.com/leavez/cocoapods-static-swift-framework — allenlinli

HAK HAK · Accepted Answer · 2018-11-14T05:11:40

A static library has to be loaded when app launches, without considering wether if its required right away or not. At the other hand a dynamic library is loaded only when it is required, hence improving the launch timings of the app and decreasing the memory pressure of the phone.

As an example consider I am using an e-commerce app which also allows to scan barcode and give details about the products. Now when I launch the app, I won't need the barcode functionality rightaway. I need to land inside the app first and start shopping. When I need to scan some barcode, I am happy to wait and let the framework loaded then but not at the start of the app.

Here is how Apple says this in its documentation:

Two important factors that determine the performance of apps are their launch times and their memory footprints. Reducing the size of an app’s executable file and minimizing its use of memory once it’s launched make the app launch faster and use less memory once it’s launched. Using dynamic libraries instead of static libraries reduces the executable file size of an app. They also allow apps to delay loading libraries with special functionality only when they’re needed instead of at launch time. This feature contributes further to reduced launch times and efficient memory use.

Documentation link: https://developer.apple.com/library/archive/documentation/DeveloperTools/Conceptual/DynamicLibraries/100-Articles/OverviewOfDynamicLibraries.html

Why Apple disallows static library in a framework?

1 Answers