Implement l10n from tar (#569)

CHANGELOG.md

@@ -1,5 +1,6 @@
 # Unreleased
 
+* Add `L10N.load_tar` to support embedded localization resources.
 * Changed `ByteLength` to display unit symbols.
 * Ignore not found error on `cargo zng l10n` cleanup.
 

crates/zng-ext-l10n/Cargo.toml

@@ -11,6 +11,11 @@ repository = "https://github.com/zng-ui/zng"
 categories = ["gui"]
 keywords = ["gui", "ui", "user-interface", "zng"]
 
+[features]
+# Support for loading localization resources from TAR and Tarball.
+tar = ["dep:flate2", "dep:tar"]
+default = ["tar"]
+
 [dependencies]
 zng-ext-l10n-proc-macros = { path = "../zng-ext-l10n-proc-macros", version = "0.2.9" }
 
@@ -36,3 +41,6 @@ once_cell = "1.19"
 dunce = "1.0"
 semver = "1.0"
 serde = { version = "1.0", features = ["derive"] }
+
+flate2 = { version = "1.0", optional = true }
+tar = { version = "0.4", optional = true }

crates/zng-ext-l10n/README.md

@@ -3,5 +3,14 @@ This crate is part of the [`zng`](https://github.com/zng-ui/zng?tab=readme-ov-fi
 
 
 <!--do doc --readme features-->
+## Cargo Features
+
+ This crate provides 1 feature flag, enabled by default.
+#### `"tar"`
+Support for loading localization resources from TAR and Tarball.
+
+*Enabled by default.*
+
+<!--do doc --readme #SECTION-END-->
 
 

crates/zng-ext-l10n/src/lib.rs

@@ -233,6 +233,19 @@ impl L10N {
         self.load(L10nDir::open(dir))
     }
 
+    /// Load localization resources from a `.tar` or `.tar.gz` container.
+    ///
+    /// The expected container layout is `root_dir/{lang}/{file}.ftl` app files and `root_dir/{lang}/deps/{pkg-name}/{pkg-version}/{file}.ftl`
+    /// for dependencies, same as [`load_dir`], `root_dir` can have any name.
+    ///
+    /// The data can be embedded using [`include_bytes!`] or loaded into a `Vec<u8>` and must be in the `.tar` or `.tar.gz` format.
+    ///
+    /// [`load_dir`]: L10N::load_dir
+    #[cfg(feature = "tar")]
+    pub fn load_tar(&self, data: impl Into<L10nTarData>) {
+        self.load(L10nTar::load(data))
+    }
+
     /// Available localization files.
     ///
     /// The value maps lang to one or more files, the files can be from the project `dir/{lang}/{file}.ftl` or from dependencies