Improve CLI argument handling for subcommand use

src/cmd/handler.rs

@@ -0,0 +1,35 @@
+use super::clap::{App, ArgMatches};
+
+use app::*;
+
+use super::cmd_upload::CmdUpload;
+
+/// CLI argument handler.
+pub struct Handler<'a> {
+    /// The CLI matches.
+    matches: ArgMatches<'a>,
+}
+
+impl<'a: 'b, 'b> Handler<'a> {
+    /// Build the application CLI definition.
+    pub fn build() -> App<'a, 'b> {
+        App::new(APP_NAME)
+            .version(APP_VERSION)
+            .author(APP_AUTHOR)
+            .about(APP_ABOUT)
+            .subcommand(CmdUpload::build().display_order(1))
+    }
+
+    /// Parse CLI arguments.
+    pub fn parse() -> Handler<'a> {
+        // Build the application CLI definition, get the matches
+        Handler {
+            matches: Handler::build().get_matches(),
+        }
+    }
+
+    /// Get the upload sub command, if matched.
+    pub fn upload(&'a self) -> Option<CmdUpload<'a>> {
+        CmdUpload::parse(&self.matches)
+    }
+}