| # Objective C example |
| |
| This example shows how to use FFIgen to generate bindings for an Objective C |
| library. It uses the AVFAudio framework to play audio files. |
| |
| ``` |
| dart play_audio.dart test.mp3 |
| ``` |
| |
| ## Config notes |
| |
| The FFIgen config for an Objective C library looks very similar to a C library. |
| The most important difference is that you must set `FfiGenerator.objectiveC`. |
| If you want to filter which interfaces are included, you can use the |
| `FfiGenerator.visitors` option to inspect AST nodes and set `node.isIncluded = true` |
| on the interfaces you want to generate. |
| |
| It is recommended that you filter out just about everything you're not |
| interested in binding (see the FFIgen config in [generate_code.dart](./generate_code.dart)). |
| Virtually all Objective C libraries depend on Apple's internal libraries, which |
| are huge. Filtering can reduce the generated bindings from millions of lines to |
| thousands. |
| |
| In this example, we're only interested in `AVAudioPlayer`, so we've filtered out |
| everything else. FFIgen will automatically pull in anything referenced by |
| any of the fields or methods of `AVAudioPlayer`, but by default they're |
| generated as stubs. To generate full bindings for the transient dependencies, |
| set `node.isIncluded = true` for them in your visitor, or set `Interfaces.includeTransitive` to `true`. |
| |
| ## Generating bindings |
| |
| At the root of this example (`example/objective_c`), run: |
| |
| ``` |
| dart run generate_code.dart |
| ``` |
| |
| This will generate [avf_audio_bindings.dart](./avf_audio_bindings.dart). |
