Trait Backend 

pub trait Backend:
    Sized
    + Send
    + Sync {
    const DEFAULT_PATH: &'static str;
    const CACHE_PATHS: &'static [&'static str];

    // Required methods
    fn path(&self) -> &Path;
    fn init(
        project: &Project,
    ) -> impl Future<Output = Result<Self, FailToInitBackend>> + Send;
    fn supports(&self, platform: TargetPlatform) -> bool;
    fn build(
        &self,
        project: &Project,
        platform: TargetPlatform,
        options: BuildOptions,
    ) -> impl Future<Output = Result<PathBuf>> + Send;
    fn package(
        &self,
        project: &Project,
        platform: TargetPlatform,
        options: PackageOptions,
    ) -> impl Future<Output = Result<Artifact>> + Send;
    fn clean(
        &self,
        project: &Project,
        platform: TargetPlatform,
    ) -> impl Future<Output = Result<()>> + Send;
}

Trait for backends in a WaterUI project.

A backend handles building and packaging for specific platforms. Each backend knows:

• Which platforms it supports
• How to build Rust code for those platforms
• How to package artifacts for distribution

Required Associated Constants

const DEFAULT_PATH: &'static str

The default relative path for this backend (e.g., “android”, “apple”).

const CACHE_PATHS: &'static [&'static str]

Paths relative to the backend directory that should be preserved during re-scaffolding.

These typically contain build caches that are expensive to regenerate. During reinit_backend(), only items NOT in this list are deleted before calling init().

Required Methods

fn path(&self) -> &Path

Get the relative path for this backend instance.

This is relative to Backends::path().

fn init( project: &Project, ) -> impl Future<Output = Result<Self, FailToInitBackend>> + Send

Initialize the backend for the given project.

Creates necessary files/folders for the backend at project.backend_path::<Self>(). Returns the initialized backend configuration.

fn supports(&self, platform: TargetPlatform) -> bool

Check if this backend supports the given platform.

fn build( &self, project: &Project, platform: TargetPlatform, options: BuildOptions, ) -> impl Future<Output = Result<PathBuf>> + Send

Build the Rust library for the target platform.

Returns the target directory path where the built library is located.

fn package( &self, project: &Project, platform: TargetPlatform, options: PackageOptions, ) -> impl Future<Output = Result<Artifact>> + Send

Package the project for the target platform.

Returns the artifact (e.g., .app, .apk, binary).

fn clean( &self, project: &Project, platform: TargetPlatform, ) -> impl Future<Output = Result<()>> + Send

Clean build artifacts for the platform.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl Backend for AndroidBackend

const DEFAULT_PATH: &'static str = "android"

const CACHE_PATHS: &'static [&'static str]

impl Backend for AppleBackend

const DEFAULT_PATH: &'static str = "apple"

const CACHE_PATHS: &'static [&'static str]

impl Backend for Esp32Backend

const DEFAULT_PATH: &'static str = "esp32"

const CACHE_PATHS: &'static [&'static str]

impl Backend for Gtk4Backend

const DEFAULT_PATH: &'static str = "gtk4"

const CACHE_PATHS: &'static [&'static str]

impl Backend for HydrolysisBackend

const DEFAULT_PATH: &'static str = "hydrolysis"

const CACHE_PATHS: &'static [&'static str]

impl Backend for WinUiBackend

const DEFAULT_PATH: &'static str = "winui"

const CACHE_PATHS: &'static [&'static str]