1 files changed, 53 insertions, 0 deletions
diff --git a/clap/examples/17_yaml.rs b/clap/examples/17_yaml.rs
new file mode 100644
index 0000000..3353d73
--- /dev/null
+++ b/clap/examples/17_yaml.rs
@@ -0,0 +1,53 @@
+// In order to use YAML to define your CLI you must compile clap with the "yaml" feature because
+// it's **not** included by default.
+//
+// In order to do this, ensure your Cargo.toml looks like one of the following:
+//
+// [dependencies.clap]
+// features = ["yaml"]
+//
+// __OR__
+//
+// [dependencies]
+// clap = { features = ["yaml"] }
+
+
+// Using yaml requires calling a clap macro `load_yaml!()` so we must use the '#[macro_use]'
+// directive
+#[macro_use]
+extern crate clap;
+
+#[cfg(feature = "yaml")]
+fn main() {
+    use clap::App;
+
+    // To load a yaml file containing our CLI definition such as the example '17_yaml.yml' we can
+    // use the convenience macro which loads the file at compile relative to the current file
+    // similar to how modules are found.
+    //
+    // Then we pass that yaml object to App to build the CLI.
+    //
+    // Finally we call get_matches() to start the parsing process. We use the matches just as we
+    // normally would
+    let yml = load_yaml!("17_yaml.yml");
+    let m = App::from_yaml(yml).get_matches();
+
+    // Because the example 17_yaml.yml is rather large we'll just look a single arg so you can
+    // see that it works...
+    if let Some(mode) = m.value_of("mode") {
+        match mode {
+            "vi" => println!("You are using vi"),
+            "emacs" => println!("You are using emacs..."),
+            _      => unreachable!()
+        }
+    } else {
+        println!("--mode <MODE> wasn't used...");
+    }
+}
+
+#[cfg(not(feature = "yaml"))]
+fn main() {
+    // As stated above, if clap is not compiled with the YAML feature, it is disabled.
+    println!("YAML feature is disabled.");
+    println!("Pass --features yaml to cargo when trying this example.");
+}