Add a relatively simple way to compile and generate Swift bindings.

docs/manual/src/SUMMARY.md

@@ -32,6 +32,7 @@
 - [Configuration](./swift/configuration.md)
 - [Building a Swift module](./swift/module.md)
 - [Integrating with Xcode](./swift/xcode.md)
+- [Wrapped in Framework](./swift/framework.md)
 
 # Internals
 - [Design Principles](./internals/design_principles.md)

docs/manual/src/swift/framework.md

@@ -0,0 +1,85 @@
+# Rust project as individual iOS framework
+
+Wrap the Rust crate into an iOS Framework, allowing separate modifications to the related Rust code and UniFFI-generated program configurations for easier integration management and usage in the future.
+
+Overall, you need:
+
+1. Generate an Xcode project file for the Rust crate and compile it into a static library.
+2. Create a new iOS Framework project and import the generated target dependencies.
+3. Compile UDL file to generate related Swift bindings.
+4. Import the generated binding header file into the public header files of the Framework.
+
+## Compile Rust crate using `cargo-xcode`
+
+First, you need to install `cargo-xcode`. This tool generates Xcode project files to compile your 
+Rust porject into a static library.
+
+```
+cargo install cargo-xcode
+```
+
+We need to modify the `Cargo.toml` file and add crate-type = ["lib", "staticlib"] in the [lib] section. Here you can add other types according to your needs, but only `staticlib` and `cdylib` can be recognized by `cargo-xcode`.
+
+To generate the project run:
+
+```
+cargo xcode
+```
+
+This will generate a `<rust-project-name>.xcodeproj` file.
+
+## Create a Framework and add dependencies
+
+* Create a new iOS Framework project and drag the `<rust-project-name>.xcodeproj` mentioned above into it.
+* Add `<rust-project-name>-staticlib` to `Build Phases - Target Dependencies` in the iOS Framework.
+* Add `lib<rust-project-name>_static.a` to the `Link Binary With Libraries` in your iOS Framework project.
+
+## Generate bindings
+
+In the iOS Framework's `Build Rules`, add a `Run Script` to handle `*.udl` and generate the corresponding bindings.
+
+* Add a build rule processing files with names matching `*.udl`.
+  * Use something like the following as the custom script:
+    * `$HOME/.cargo/bin/uniffi-bindgen-cli generate $INPUT_FILE_PATH --language swift --out-dir $INPUT_FILE_DIR/Generated`
+  * Add both the Swift file and the generated bridging header as output files:
+    * `$(INPUT_FILE_DIR)/Generated/$(INPUT_FILE_BASE).swift`
+    * `$(INPUT_FILE_DIR)/Generated/$(INPUT_FILE_BASE)FFI.h`
+
+* Add your `.udl` file to the `Compile Sources` build phase for your framework, so that Xcode will process it using the new build rule and will include the resulting outputs in the build.
+
+You do not need to add the generated Swift code to the list of `Compile Sources` and should not attempt to compile it explicitly; Xcode will figure out what it needs to do with this code based on it being generated from the Build Rule for your `.udl` file.
+
+## Import header files
+
+Import the generated header file in `<framework-name>.h` of iOS Framework.
+
+```c
+#import <Foundation/Foundation.h>
+
+//! Project version number for <framework-name>.
+FOUNDATION_EXPORT double <framework-name>VersionNumber;
+
+//! Project version string for <framework-name>.
+FOUNDATION_EXPORT const unsigned char <framework-name>VersionString[];
+
+// In this header, you should import all the public headers of your framework using statements like #import <framework-name>/PublicHeader.h>
+
+#import "Generated/<rust-project-name>FFI.h"
+```
+
+As a last step add the generated header file as a Public header in the "Headers" build phase of your project.
+
+## Use the framework in an application
+
+After completing the above steps, you can now use your Framework by dragging it into your project and importing `<framework-name>`.
+
+It also provides an [ios-with-framework](examples/app/ios-with-framework/) that you can check out under examples/app/ios-with-framework/.
+
+* `ios-with-framework`: Root directory of the sample project
+
+  * `iOS-UniFFI-Framework`: Includes handling of compiling Rust crates into static libraries and generating bindings.
+  * `iOS-UniFFI-App`: Includes the use of the generated framework.
+
+## Known issues
+
+* If you encounter an error when generating bindings, please check if `uniffi-bindgen-cli` is installed. If the path is incorrect, please modify the script path in `Build Rules`.