feat: add cli support to build assets from executable

See #3402 (reply in thread)

packages/cli/src/cli/build_assets.rs

@@ -0,0 +1,63 @@
+use std::{
+    fs::create_dir_all,
+    path::{Path, PathBuf},
+};
+
+use crate::{Result, StructuredOutput};
+use clap::Parser;
+use dioxus_cli_opt::{process_file_to, AssetManifest};
+use tracing::debug;
+
+#[derive(Clone, Debug, Parser)]
+pub struct BuildAssets {
+    /// The source executable to build assets for.
+    pub(crate) executable: PathBuf,
+
+    /// The source directory for the assets.
+    pub(crate) source: PathBuf,
+
+    /// The destination directory for the assets.
+    pub(crate) destination: PathBuf,
+}
+
+impl BuildAssets {
+    pub async fn run(self) -> Result<StructuredOutput> {
+        let mut manifest = AssetManifest::default();
+        manifest.add_from_object_path(&self.executable)?;
+
+        create_dir_all(&self.destination)?;
+        for (path, asset) in manifest.assets.iter() {
+            let relative_path = turn_asset_path_into_relative_path(path);
+            let source_path = self.source.join(relative_path);
+            let destination_path = self.destination.join(asset.bundled_path());
+            debug!(
+                "Processing asset {} --> {} {:#?}",
+                source_path.display(),
+                destination_path.display(),
+                asset
+            );
+            process_file_to(asset.options(), &source_path, &destination_path)?;
+        }
+
+        Ok(StructuredOutput::Success)
+    }
+}
+
+/// Hack to turn an absolute path into a relative path.
+///
+/// For example, the executable path might have the absolute path:
+/// "/build/lknys4lnckh88mxvi7pba1zsvgfyh1a1-source/assets/header.svg
+///
+/// And we need a relative path to the source directory:
+/// "assets/header.svg"
+fn turn_asset_path_into_relative_path(asset_path: &Path) -> PathBuf {
+    let components = asset_path
+        .components()
+        .skip_while(|c| c.as_os_str() != "assets")
+        .collect::<Vec<_>>();
+
+    components.iter().fold(PathBuf::new(), |mut acc, c| {
+        acc.push(c);
+        acc
+    })
+}

packages/cli/src/cli/mod.rs

@@ -1,5 +1,6 @@
 pub(crate) mod autoformat;
 pub(crate) mod build;
+pub(crate) mod build_assets;
 pub(crate) mod bundle;
 pub(crate) mod check;
 pub(crate) mod clean;
@@ -95,6 +96,10 @@ pub(crate) enum Commands {
     #[clap(subcommand)]
     #[clap(name = "config")]
     Config(config::Config),
+
+    /// Build the assets for a specific target.
+    #[clap(name = "build_assets")]
+    BuildAssets(build_assets::BuildAssets),
 }
 
 impl Display for Commands {
@@ -112,6 +117,7 @@ impl Display for Commands {
             Commands::Bundle(_) => write!(f, "bundle"),
             Commands::Run(_) => write!(f, "run"),
             Commands::Doctor(_) => write!(f, "doctor"),
+            Commands::BuildAssets(_) => write!(f, "build_assets"),
         }
     }
 }

packages/cli/src/main.rs

@@ -53,6 +53,7 @@ async fn main() {
         Commands::Bundle(opts) => opts.bundle().await,
         Commands::Run(opts) => opts.run().await,
         Commands::Doctor(opts) => opts.run().await,
+        Commands::BuildAssets(opts) => opts.run().await,
     };
 
     // Provide a structured output for third party tools that can consume the output of the CLI