feat(core): resources on mobile apps (#10696)

* feat(core): resources on mobile apps

* resources dir on android

Author: lucasfernog

.changes/inject-mobile-resources.md

@@ -0,0 +1,6 @@
+---
+"tauri-cli": patch:feat
+"@tauri-apps/cli": patch:feat
+---
+
+Inject configured resources on mobile apps.

.changes/resource-dir-android.md

@@ -0,0 +1,5 @@
+---
+"tauri-utils": patch:bug
+---
+
+Implemented `resource_dir` on Android, which returns a URI that needs to be resolved using [AssetManager::open](https://developer.android.com/reference/android/content/res/AssetManager#open(java.lang.String,%20int)). This will be handled by the file system plugin.

.changes/resource-dir-ios.md

@@ -0,0 +1,5 @@
+---
+"tauri-utils": patch:bug
+---
+
+Fix `resource_dir` on iOS.

core/tauri-utils/src/platform.rs

@@ -15,6 +15,9 @@ use crate::{Env, PackageInfo};
 
 mod starting_binary;
 
+#[cfg(target_os = "android")]
+pub const ANDROID_ASSET_PROTOCOL_URI_PREFIX: &str = "asset://localhost/";
+
 /// Platform target.
 #[derive(PartialEq, Eq, Copy, Debug, Clone, Serialize, Deserialize)]
 #[cfg_attr(feature = "schema", derive(schemars::JsonSchema))]
@@ -256,7 +259,13 @@ fn is_cargo_output_directory(path: &Path) -> bool {
 /// `${exe_dir}/../lib/${exe_name}`.
 ///
 /// On MacOS, it's `${exe_dir}../Resources` (inside .app).
+///
+/// On iOS, it's `${exe_dir}/assets`.
+///
+/// Android uses a special URI prefix that is resolved by the Tauri file system plugin `asset://localhost/`
 pub fn resource_dir(package_info: &PackageInfo, env: &Env) -> crate::Result<PathBuf> {
+  #[cfg(target_os = "android")]
+  return Ok(PathBuf::from(ANDROID_ASSET_PROTOCOL_URI_PREFIX));
   let exe = current_exe()?;
   resource_dir_from(exe, package_info, env)
 }
@@ -320,6 +329,11 @@ fn resource_dir_from<P: AsRef<Path>>(
       .map_err(Into::into);
   }
 
+  #[cfg(target_os = "ios")]
+  {
+    res = exe_dir.join("assets").canonicalize().map_err(Into::into);
+  }
+
   res
 }
 

core/tauri/mobile/android/src/main/java/app/tauri/PathPlugin.kt

@@ -12,6 +12,8 @@ import app.tauri.plugin.Plugin
 import app.tauri.plugin.Invoke
 import app.tauri.plugin.JSObject
 
+const val TAURI_ASSETS_DIRECTORY_URI = "asset://localhost/"
+
 @TauriPlugin
 class PathPlugin(private val activity: Activity): Plugin(activity) {
     private fun resolvePath(invoke: Invoke, path: String?) {
@@ -67,8 +69,7 @@ class PathPlugin(private val activity: Activity): Plugin(activity) {
 
     @Command
     fun getResourcesDir(invoke: Invoke) {
-        // TODO
-        resolvePath(invoke, activity.cacheDir.absolutePath)
+        resolvePath(invoke, TAURI_ASSETS_DIRECTORY_URI)
     }
 
     @Command

examples/api/src-tauri/Cargo.lock

@@ -0,0 +1,21 @@
+// Copyright 2019-2024 Tauri Programme within The Commons Conservancy
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-License-Identifier: MIT
+
+use anyhow::Result;
+use std::path::Path;
+
+pub fn copy_file(from: impl AsRef<Path>, to: impl AsRef<Path>) -> Result<()> {
+  let from = from.as_ref();
+  let to = to.as_ref();
+  if !from.exists() {
+    return Err(anyhow::anyhow!("{:?} does not exist", from));
+  }
+  if !from.is_file() {
+    return Err(anyhow::anyhow!("{:?} is not a file", from));
+  }
+  let dest_dir = to.parent().expect("No data in parent");
+  std::fs::create_dir_all(dest_dir)?;
+  std::fs::copy(from, to)?;
+  Ok(())
+}

tooling/cli/src/helpers/fs.rs

@@ -8,6 +8,7 @@ pub mod cargo_manifest;
 pub mod config;
 pub mod flock;
 pub mod framework;
+pub mod fs;
 pub mod npm;
 pub mod plugins;
 pub mod prompts;

tooling/cli/src/helpers/mod.rs

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: MIT
 
 use super::{
-  configure_cargo, delete_codegen_vars, ensure_init, env, get_app, get_config, inject_assets,
+  configure_cargo, delete_codegen_vars, ensure_init, env, get_app, get_config, inject_resources,
   log_finished, open_and_wait, MobileTarget, OptionsHandle,
 };
 use crate::{
@@ -209,7 +209,7 @@ fn run_build(
     cli_options,
   )?;
 
-  inject_assets(config, tauri_config.lock().unwrap().as_ref().unwrap())?;
+  inject_resources(config, tauri_config.lock().unwrap().as_ref().unwrap())?;
 
   let apk_outputs = if options.apk {
     apk::build(

tooling/cli/src/mobile/android/build.rs

@@ -4,7 +4,7 @@
 
 use super::{
   configure_cargo, delete_codegen_vars, device_prompt, ensure_init, env, get_app, get_config,
-  inject_assets, open_and_wait, MobileTarget,
+  inject_resources, open_and_wait, MobileTarget,
 };
 use crate::{
   dev::Options as DevOptions,
@@ -244,7 +244,7 @@ fn run_dev(
         cli_options,
       )?;
 
-      inject_assets(config, tauri_config.lock().unwrap().as_ref().unwrap())?;
+      inject_resources(config, tauri_config.lock().unwrap().as_ref().unwrap())?;
 
       if open {
         open_and_wait(config, &env)