feat: added perserve flag to the update command which preserves the new updates

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to `ewwii` are documented here.
 This changelog follows the [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) format,
 and this project adheres to [Semantic Versioning](https://semver.org/).
 
+## [0.1.4] - [UNRELEASED]
+
+### Added
+
+-   `--preserve` flag to the `update` command which preserves the new updates.
+
 ## [0.1.3] - 2025-09-17
 
 ### Changed

crates/ewwii/src/app.rs

@@ -79,6 +79,7 @@ pub enum DaemonCommand {
     ListActiveWindows(DaemonResponseSender),
     TriggerUpdateUI {
         inject_vars: Option<HashMap<String, String>>,
+        should_preserve_state: bool,
         sender: DaemonResponseSender,
     },
     CallRhaiFns {
@@ -309,8 +310,8 @@ impl<B: DisplayBackend> App<B> {
                 let output = format!("{:#?}", &self);
                 sender.send_success(output)?
             }
-            DaemonCommand::TriggerUpdateUI { inject_vars, sender } => {
-                let output = match self.trigger_ui_update_with(inject_vars) {
+            DaemonCommand::TriggerUpdateUI { inject_vars, should_preserve_state, sender } => {
+                let output = match self.trigger_ui_update_with(inject_vars, should_preserve_state) {
                     Ok(_) => String::new(),
                     Err(e) => e.to_string(),
                 };
@@ -676,10 +677,15 @@ impl<B: DisplayBackend> App<B> {
     pub fn trigger_ui_update_with(
         &self,
         inject_vars: Option<HashMap<String, String>>,
+        should_preserve_state: bool,
     ) -> Result<()> {
         let compiled_ast = self.ewwii_config.get_owned_compiled_ast();
         let config_path = self.paths.get_rhai_path();
 
+        if !config_path.exists() {
+            bail!("The configuration file `{}` does not exist", config_path.display());
+        }
+
         let mut reeval_parser = ParseConfig::new();
         let rhai_code = reeval_parser.code_from_file(&config_path)?;
 
@@ -695,12 +701,18 @@ impl<B: DisplayBackend> App<B> {
 
         if let Some(vars) = inject_vars {
             for (name, val) in vars {
-                scope.set_value(name, Dynamic::from(val));
-            }
-        }
+                scope.set_value(name.clone(), Dynamic::from(val.clone()));
 
-        if !config_path.exists() {
-            bail!("The configuration file `{}` does not exist", config_path.display());
+                // Preserving the new state.
+                // ---
+                // This is esstentially storing the inject variables
+                // in the poll/listen variable store (or the `pl_handler_store` in self)
+                if should_preserve_state {
+                    if let Some(maybe_store) = &self.pl_handler_store {
+                        maybe_store.write().unwrap().insert(name.clone(), val);
+                    }
+                }
+            }
         }
 
         let new_root_widget =

crates/ewwii/src/opts.rs

@@ -197,6 +197,10 @@ pub enum ActionWithServer {
         /// Only variables used by the widget tree will affect the UI.
         #[arg(long = "inject", short, value_parser = parse_inject_var_map)]
         inject_vars: Option<HashMap<String, String>>,
+
+        /// Preserve the new updates. Only meaningful if used with inject.
+        #[arg(long = "preserve", short = 'p')]
+        should_preserve_state: bool,
     },
 
     /// Call rhai functions. (NOTE: All poll/listen will default to their initial value)
@@ -267,9 +271,10 @@ impl ActionWithServer {
         self,
     ) -> (app::DaemonCommand, Option<daemon_response::DaemonResponseReceiver>) {
         let command = match self {
-            ActionWithServer::TriggerUpdateUI { inject_vars } => {
+            ActionWithServer::TriggerUpdateUI { inject_vars, should_preserve_state } => {
                 return with_response_channel(|sender| app::DaemonCommand::TriggerUpdateUI {
                     inject_vars,
+                    should_preserve_state,
                     sender,
                 })
             }