fix onAppStart docs

revel/skeleton/app/init.go

@@ -29,7 +29,11 @@ func init() {
 		revel.ActionInvoker,           // Invoke the action.
 	}
 
-	// register startup functions with OnAppStart ( order dependent )
+
+	// register startup functions with OnAppStart
+	// revel.DevMode and revel.RunMode only work inside of OnAppStart. See Example Startup Script
+	// ( order dependent )
+	// revel.OnAppStart(ExampleStartupScript)
 	// revel.OnAppStart(InitDB)
 	// revel.OnAppStart(FillCache)
 }
@@ -45,3 +49,11 @@ var HeaderFilter = func(c *revel.Controller, fc []revel.Filter) {
 
 	fc[0](c, fc[1:]) // Execute the next filter stage.
 }
+
+func ExampleStartupScript() {
+	// revel.DevMod and revel.RunMode work here
+	// Use this script to check for dev mode and set dev/prod startup scripts here!
+	if revel.DevMode == true {
+		os.Setenv("SOME_ENV_VAR", "VALUE")
+	}
+}