Struct tauri::StateManager

pub struct StateManager(_);

The Tauri state manager.

Implementations

impl StateManager

pub fn get<T: Send + Sync + 'static>(&self) -> State<'_, T>

Gets the state associated with the specified type.

Examples found in repository

src/manager.rs (line 510)

  fn prepare_pending_window(
    &self,
    mut pending: PendingWindow<EventLoopMessage, R>,
    label: &str,
    window_labels: &[String],
    app_handle: AppHandle<R>,
    web_resource_request_handler: Option<Box<WebResourceRequestHandler>>,
  ) -> crate::Result<PendingWindow<EventLoopMessage, R>> {
    let is_init_global = self.inner.config.build.with_global_tauri;
    let plugin_init = self
      .inner
      .plugins
      .lock()
      .expect("poisoned plugin store")
      .initialization_script();

    let pattern_init = PatternJavascript {
      pattern: self.pattern().into(),
    }
    .render_default(&Default::default())?;

    let ipc_init = IpcJavascript {
      isolation_origin: &match self.pattern() {
        #[cfg(feature = "isolation")]
        Pattern::Isolation { schema, .. } => crate::pattern::format_real_schema(schema),
        _ => "".to_string(),
      },
    }
    .render_default(&Default::default())?;

    let mut webview_attributes = pending.webview_attributes;

    let mut window_labels = window_labels.to_vec();
    let l = label.to_string();
    if !window_labels.contains(&l) {
      window_labels.push(l);
    }
    webview_attributes = webview_attributes
      .initialization_script(&self.inner.invoke_initialization_script)
      .initialization_script(&format!(
        r#"
          Object.defineProperty(window, '__TAURI_METADATA__', {{
            value: {{
              __windows: {window_labels_array}.map(function (label) {{ return {{ label: label }} }}),
              __currentWindow: {{ label: {current_window_label} }}
            }}
          }})
        "#,
        window_labels_array = serde_json::to_string(&window_labels)?,
        current_window_label = serde_json::to_string(&label)?,
      ))
      .initialization_script(&self.initialization_script(&ipc_init.into_string(),&pattern_init.into_string(),&plugin_init, is_init_global)?)
      ;

    #[cfg(feature = "isolation")]
    if let Pattern::Isolation { schema, .. } = self.pattern() {
      webview_attributes = webview_attributes.initialization_script(
        &IsolationJavascript {
          origin: self.get_browser_origin(),
          isolation_src: &crate::pattern::format_real_schema(schema),
          style: tauri_utils::pattern::isolation::IFRAME_STYLE,
        }
        .render_default(&Default::default())?
        .into_string(),
      );
    }

    pending.webview_attributes = webview_attributes;

    let mut registered_scheme_protocols = Vec::new();

    for (uri_scheme, protocol) in &self.inner.uri_scheme_protocols {
      registered_scheme_protocols.push(uri_scheme.clone());
      let protocol = protocol.clone();
      let app_handle = Mutex::new(app_handle.clone());
      pending.register_uri_scheme_protocol(uri_scheme.clone(), move |p| {
        (protocol.protocol)(&app_handle.lock().unwrap(), p)
      });
    }

    let window_url = Url::parse(&pending.url).unwrap();
    let window_origin =
      if cfg!(windows) && window_url.scheme() != "http" && window_url.scheme() != "https" {
        format!("https://{}.localhost", window_url.scheme())
      } else {
        format!(
          "{}://{}{}",
          window_url.scheme(),
          window_url.host().unwrap(),
          if let Some(port) = window_url.port() {
            format!(":{}", port)
          } else {
            "".into()
          }
        )
      };

    if !registered_scheme_protocols.contains(&"tauri".into()) {
      pending.register_uri_scheme_protocol(
        "tauri",
        self.prepare_uri_scheme_protocol(&window_origin, web_resource_request_handler),
      );
      registered_scheme_protocols.push("tauri".into());
    }

    #[cfg(protocol_asset)]
    if !registered_scheme_protocols.contains(&"asset".into()) {
      use crate::api::file::SafePathBuf;
      use tokio::io::{AsyncReadExt, AsyncSeekExt};
      use url::Position;
      let asset_scope = self.state().get::<crate::Scopes>().asset_protocol.clone();
      pending.register_uri_scheme_protocol("asset", move |request| {
        let parsed_path = Url::parse(request.uri())?;
        let filtered_path = &parsed_path[..Position::AfterPath];
        let path = filtered_path
          .strip_prefix("asset://localhost/")
          // the `strip_prefix` only returns None when a request is made to `https://tauri.$P` on Windows
          // where `$P` is not `localhost/*`
          .unwrap_or("");
        let path = percent_encoding::percent_decode(path.as_bytes())
          .decode_utf8_lossy()
          .to_string();

        if let Err(e) = SafePathBuf::new(path.clone().into()) {
          debug_eprintln!("asset protocol path \"{}\" is not valid: {}", path, e);
          return HttpResponseBuilder::new().status(403).body(Vec::new());
        }

        if !asset_scope.is_allowed(&path) {
          debug_eprintln!("asset protocol not configured to allow the path: {}", path);
          return HttpResponseBuilder::new().status(403).body(Vec::new());
        }

        let path_ = path.clone();

        let mut response =
          HttpResponseBuilder::new().header("Access-Control-Allow-Origin", &window_origin);

        // handle 206 (partial range) http request
        if let Some(range) = request
          .headers()
          .get("range")
          .and_then(|r| r.to_str().map(|r| r.to_string()).ok())
        {
          #[derive(Default)]
          struct RangeMetadata {
            file: Option<tokio::fs::File>,
            range: Option<crate::runtime::http::HttpRange>,
            metadata: Option<std::fs::Metadata>,
            headers: HashMap<&'static str, String>,
            status_code: u16,
            body: Vec<u8>,
          }

          let mut range_metadata = crate::async_runtime::safe_block_on(async move {
            let mut data = RangeMetadata::default();
            // open the file
            let mut file = match tokio::fs::File::open(path_.clone()).await {
              Ok(file) => file,
              Err(e) => {
                debug_eprintln!("Failed to open asset: {}", e);
                data.status_code = 404;
                return data;
              }
            };
            // Get the file size
            let file_size = match file.metadata().await {
              Ok(metadata) => {
                let len = metadata.len();
                data.metadata.replace(metadata);
                len
              }
              Err(e) => {
                debug_eprintln!("Failed to read asset metadata: {}", e);
                data.file.replace(file);
                data.status_code = 404;
                return data;
              }
            };
            // parse the range
            let range = match crate::runtime::http::HttpRange::parse(
              &if range.ends_with("-*") {
                range.chars().take(range.len() - 1).collect::<String>()
              } else {
                range.clone()
              },
              file_size,
            ) {
              Ok(r) => r,
              Err(e) => {
                debug_eprintln!("Failed to parse range {}: {:?}", range, e);
                data.file.replace(file);
                data.status_code = 400;
                return data;
              }
            };

            // FIXME: Support multiple ranges
            // let support only 1 range for now
            if let Some(range) = range.first() {
              data.range.replace(*range);
              let mut real_length = range.length;
              // prevent max_length;
              // specially on webview2
              if range.length > file_size / 3 {
                // max size sent (400ko / request)
                // as it's local file system we can afford to read more often
                real_length = std::cmp::min(file_size - range.start, 1024 * 400);
              }

              // last byte we are reading, the length of the range include the last byte
              // who should be skipped on the header
              let last_byte = range.start + real_length - 1;

              data.headers.insert("Connection", "Keep-Alive".into());
              data.headers.insert("Accept-Ranges", "bytes".into());
              data
                .headers
                .insert("Content-Length", real_length.to_string());
              data.headers.insert(
                "Content-Range",
                format!("bytes {}-{}/{}", range.start, last_byte, file_size),
              );

              if let Err(e) = file.seek(std::io::SeekFrom::Start(range.start)).await {
                debug_eprintln!("Failed to seek file to {}: {}", range.start, e);
                data.file.replace(file);
                data.status_code = 422;
                return data;
              }

              let mut f = file.take(real_length);
              let r = f.read_to_end(&mut data.body).await;
              file = f.into_inner();
              data.file.replace(file);

              if let Err(e) = r {
                debug_eprintln!("Failed read file: {}", e);
                data.status_code = 422;
                return data;
              }
              // partial content
              data.status_code = 206;
            } else {
              data.status_code = 200;
            }

            data
          });

          for (k, v) in range_metadata.headers {
            response = response.header(k, v);
          }

          let mime_type = if let (Some(mut file), Some(metadata), Some(range)) = (
            range_metadata.file,
            range_metadata.metadata,
            range_metadata.range,
          ) {
            // if we're already reading the beginning of the file, we do not need to re-read it
            if range.start == 0 {
              MimeType::parse(&range_metadata.body, &path)
            } else {
              let (status, bytes) = crate::async_runtime::safe_block_on(async move {
                let mut status = None;
                if let Err(e) = file.rewind().await {
                  debug_eprintln!("Failed to rewind file: {}", e);
                  status.replace(422);
                  (status, Vec::with_capacity(0))
                } else {
                  // taken from https://docs.rs/infer/0.9.0/src/infer/lib.rs.html#240-251
                  let limit = std::cmp::min(metadata.len(), 8192) as usize + 1;
                  let mut bytes = Vec::with_capacity(limit);
                  if let Err(e) = file.take(8192).read_to_end(&mut bytes).await {
                    debug_eprintln!("Failed read file: {}", e);
                    status.replace(422);
                  }
                  (status, bytes)
                }
              });
              if let Some(s) = status {
                range_metadata.status_code = s;
              }
              MimeType::parse(&bytes, &path)
            }
          } else {
            MimeType::parse(&range_metadata.body, &path)
          };
          response
            .mimetype(&mime_type)
            .status(range_metadata.status_code)
            .body(range_metadata.body)
        } else {
          match crate::async_runtime::safe_block_on(async move { tokio::fs::read(path_).await }) {
            Ok(data) => {
              let mime_type = MimeType::parse(&data, &path);
              response.mimetype(&mime_type).body(data)
            }
            Err(e) => {
              debug_eprintln!("Failed to read file: {}", e);
              response.status(404).body(Vec::new())
            }
          }
        }
      });
    }

    #[cfg(feature = "isolation")]
    if let Pattern::Isolation {
      assets,
      schema,
      key: _,
      crypto_keys,
    } = &self.inner.pattern
    {
      let assets = assets.clone();
      let schema_ = schema.clone();
      let url_base = format!("{}://localhost", schema_);
      let aes_gcm_key = *crypto_keys.aes_gcm().raw();

      pending.register_uri_scheme_protocol(schema, move |request| {
        match request_to_path(request, &url_base).as_str() {
          "index.html" => match assets.get(&"index.html".into()) {
            Some(asset) => {
              let asset = String::from_utf8_lossy(asset.as_ref());
              let template = tauri_utils::pattern::isolation::IsolationJavascriptRuntime {
                runtime_aes_gcm_key: &aes_gcm_key,
              };
              match template.render(asset.as_ref(), &Default::default()) {
                Ok(asset) => HttpResponseBuilder::new()
                  .mimetype("text/html")
                  .body(asset.into_string().as_bytes().to_vec()),
                Err(_) => HttpResponseBuilder::new()
                  .status(500)
                  .mimetype("text/plain")
                  .body(Vec::new()),
              }
            }

            None => HttpResponseBuilder::new()
              .status(404)
              .mimetype("text/plain")
              .body(Vec::new()),
          },
          _ => HttpResponseBuilder::new()
            .status(404)
            .mimetype("text/plain")
            .body(Vec::new()),
        }
      });
    }

    Ok(pending)
  }

  fn prepare_ipc_handler(
    &self,
    app_handle: AppHandle<R>,
  ) -> WebviewIpcHandler<EventLoopMessage, R> {
    let manager = self.clone();
    Box::new(move |window, #[allow(unused_mut)] mut request| {
      let window = Window::new(manager.clone(), window, app_handle.clone());

      #[cfg(feature = "isolation")]
      if let Pattern::Isolation { crypto_keys, .. } = manager.pattern() {
        match RawIsolationPayload::try_from(request.as_str())
          .and_then(|raw| crypto_keys.decrypt(raw))
        {
          Ok(json) => request = json,
          Err(e) => {
            let error: crate::Error = e.into();
            let _ = window.eval(&format!(
              r#"console.error({})"#,
              JsonValue::String(error.to_string())
            ));
            return;
          }
        }
      }

      match serde_json::from_str::<InvokePayload>(&request) {
        Ok(message) => {
          let _ = window.on_message(message);
        }
        Err(e) => {
          let error: crate::Error = e.into();
          let _ = window.eval(&format!(
            r#"console.error({})"#,
            JsonValue::String(error.to_string())
          ));
        }
      }
    })
  }

  pub fn get_asset(&self, mut path: String) -> Result<Asset, Box<dyn std::error::Error>> {
    let assets = &self.inner.assets;
    if path.ends_with('/') {
      path.pop();
    }
    path = percent_encoding::percent_decode(path.as_bytes())
      .decode_utf8_lossy()
      .to_string();
    let path = if path.is_empty() {
      // if the url is `tauri://localhost`, we should load `index.html`
      "index.html".to_string()
    } else {
      // skip leading `/`
      path.chars().skip(1).collect::<String>()
    };

    let mut asset_path = AssetKey::from(path.as_str());

    let asset_response = assets
      .get(&path.as_str().into())
      .or_else(|| {
        eprintln!("Asset `{}` not found; fallback to {}.html", path, path);
        let fallback = format!("{}.html", path.as_str()).into();
        let asset = assets.get(&fallback);
        asset_path = fallback;
        asset
      })
      .or_else(|| {
        debug_eprintln!(
          "Asset `{}` not found; fallback to {}/index.html",
          path,
          path
        );
        let fallback = format!("{}/index.html", path.as_str()).into();
        let asset = assets.get(&fallback);
        asset_path = fallback;
        asset
      })
      .or_else(|| {
        debug_eprintln!("Asset `{}` not found; fallback to index.html", path);
        let fallback = AssetKey::from("index.html");
        let asset = assets.get(&fallback);
        asset_path = fallback;
        asset
      })
      .ok_or_else(|| crate::Error::AssetNotFound(path.clone()))
      .map(Cow::into_owned);

    let mut csp_header = None;
    let is_html = asset_path.as_ref().ends_with(".html");

    match asset_response {
      Ok(asset) => {
        let final_data = if is_html {
          let mut asset = String::from_utf8_lossy(&asset).into_owned();
          if let Some(csp) = self.csp() {
            csp_header.replace(set_csp(
              &mut asset,
              self.inner.assets.clone(),
              &asset_path,
              self,
              csp,
            ));
          }

          asset.as_bytes().to_vec()
        } else {
          asset
        };
        let mime_type = MimeType::parse(&final_data, &path);
        Ok(Asset {
          bytes: final_data.to_vec(),
          mime_type,
          csp_header,
        })
      }
      Err(e) => {
        debug_eprintln!("{:?}", e); // TODO log::error!
        Err(Box::new(e))
      }
    }
  }

  #[allow(clippy::type_complexity)]
  fn prepare_uri_scheme_protocol(
    &self,
    window_origin: &str,
    web_resource_request_handler: Option<
      Box<dyn Fn(&HttpRequest, &mut HttpResponse) + Send + Sync>,
    >,
  ) -> Box<dyn Fn(&HttpRequest) -> Result<HttpResponse, Box<dyn std::error::Error>> + Send + Sync>
  {
    let manager = self.clone();
    let window_origin = window_origin.to_string();
    Box::new(move |request| {
      let path = request
        .uri()
        .split(&['?', '#'][..])
        // ignore query string and fragment
        .next()
        .unwrap()
        .strip_prefix("tauri://localhost")
        .map(|p| p.to_string())
        // the `strip_prefix` only returns None when a request is made to `https://tauri.$P` on Windows
        // where `$P` is not `localhost/*`
        .unwrap_or_else(|| "".to_string());
      let asset = manager.get_asset(path)?;
      let mut builder = HttpResponseBuilder::new()
        .header("Access-Control-Allow-Origin", &window_origin)
        .mimetype(&asset.mime_type);
      if let Some(csp) = &asset.csp_header {
        builder = builder.header("Content-Security-Policy", csp);
      }
      let mut response = builder.body(asset.bytes)?;
      if let Some(handler) = &web_resource_request_handler {
        handler(request, &mut response);

        // if it's an HTML file, we need to set the CSP meta tag on Linux
        #[cfg(target_os = "linux")]
        if let Some(response_csp) = response.headers().get("Content-Security-Policy") {
          let response_csp = String::from_utf8_lossy(response_csp.as_bytes());
          let body = set_html_csp(&String::from_utf8_lossy(response.body()), &response_csp);
          *response.body_mut() = body.as_bytes().to_vec();
        }
      } else {
        #[cfg(target_os = "linux")]
        {
          if let Some(csp) = &asset.csp_header {
            let body = set_html_csp(&String::from_utf8_lossy(response.body()), csp);
            *response.body_mut() = body.as_bytes().to_vec();
          }
        }
      }
      Ok(response)
    })
  }

  fn initialization_script(
    &self,
    ipc_script: &str,
    pattern_script: &str,
    plugin_initialization_script: &str,
    with_global_tauri: bool,
  ) -> crate::Result<String> {
    #[derive(Template)]
    #[default_template("../scripts/init.js")]
    struct InitJavascript<'a> {
      origin: String,
      #[raw]
      pattern_script: &'a str,
      #[raw]
      ipc_script: &'a str,
      #[raw]
      bundle_script: &'a str,
      // A function to immediately listen to an event.
      #[raw]
      listen_function: &'a str,
      #[raw]
      core_script: &'a str,
      #[raw]
      event_initialization_script: &'a str,
      #[raw]
      plugin_initialization_script: &'a str,
      #[raw]
      freeze_prototype: &'a str,
      #[raw]
      hotkeys: &'a str,
    }

    let bundle_script = if with_global_tauri {
      include_str!("../scripts/bundle.global.js")
    } else {
      ""
    };

    let freeze_prototype = if self.inner.config.tauri.security.freeze_prototype {
      include_str!("../scripts/freeze_prototype.js")
    } else {
      ""
    };

    #[cfg(any(debug_assertions, feature = "devtools"))]
    let hotkeys = &format!(
      "
      {};
      window.hotkeys('{}', () => {{
        window.__TAURI_INVOKE__('tauri', {{
          __tauriModule: 'Window',
          message: {{
            cmd: 'manage',
            data: {{
              cmd: {{
                type: '__toggleDevtools'
              }}
            }}
          }}
        }});
      }});
    ",
      include_str!("../scripts/hotkey.js"),
      if cfg!(target_os = "macos") {
        "command+option+i"
      } else {
        "ctrl+shift+i"
      }
    );
    #[cfg(not(any(debug_assertions, feature = "devtools")))]
    let hotkeys = "";

    InitJavascript {
      origin: self.get_browser_origin(),
      pattern_script,
      ipc_script,
      bundle_script,
      listen_function: &format!(
        "function listen(eventName, cb) {{ {} }}",
        crate::event::listen_js(
          self.event_listeners_object_name(),
          "eventName".into(),
          0,
          None,
          "window['_' + window.__TAURI__.transformCallback(cb) ]".into()
        )
      ),
      core_script: include_str!("../scripts/core.js"),
      event_initialization_script: &self.event_initialization_script(),
      plugin_initialization_script,
      freeze_prototype,
      hotkeys,
    }
    .render_default(&Default::default())
    .map(|s| s.into_string())
    .map_err(Into::into)
  }

  fn event_initialization_script(&self) -> String {
    format!(
      "
      Object.defineProperty(window, '{function}', {{
        value: function (eventData) {{
          const listeners = (window['{listeners}'] && window['{listeners}'][eventData.event]) || []

          for (let i = listeners.length - 1; i >= 0; i--) {{
            const listener = listeners[i]
            if (listener.windowLabel === null || listener.windowLabel === eventData.windowLabel) {{
              eventData.id = listener.id
              listener.handler(eventData)
            }}
          }}
        }}
      }});
    ",
      function = self.event_emit_function_name(),
      listeners = self.event_listeners_object_name()
    )
  }
}

#[cfg(test)]
mod test {
  use crate::{generate_context, plugin::PluginStore, StateManager, Wry};

  use super::WindowManager;

  #[test]
  fn check_get_url() {
    let context = generate_context!("test/fixture/src-tauri/tauri.conf.json", crate);
    let manager: WindowManager<Wry> = WindowManager::with_handlers(
      context,
      PluginStore::default(),
      Box::new(|_| ()),
      Box::new(|_, _| ()),
      Default::default(),
      StateManager::new(),
      Default::default(),
      Default::default(),
      (std::sync::Arc::new(|_, _, _, _| ()), "".into()),
    );

    #[cfg(custom_protocol)]
    assert_eq!(manager.get_url().to_string(), "tauri://localhost");

    #[cfg(dev)]
    assert_eq!(manager.get_url().to_string(), "http://localhost:4000/");
  }
}

impl<R: Runtime> WindowManager<R> {
  pub fn run_invoke_handler(&self, invoke: Invoke<R>) {
    (self.inner.invoke_handler)(invoke);
  }

  pub fn run_on_page_load(&self, window: Window<R>, payload: PageLoadPayload) {
    (self.inner.on_page_load)(window.clone(), payload.clone());
    self
      .inner
      .plugins
      .lock()
      .expect("poisoned plugin store")
      .on_page_load(window, payload);
  }

  pub fn extend_api(&self, invoke: Invoke<R>) {
    self
      .inner
      .plugins
      .lock()
      .expect("poisoned plugin store")
      .extend_api(invoke);
  }

  pub fn initialize_plugins(&self, app: &AppHandle<R>) -> crate::Result<()> {
    self
      .inner
      .plugins
      .lock()
      .expect("poisoned plugin store")
      .initialize(app, &self.inner.config.plugins)
  }

  pub fn prepare_window(
    &self,
    app_handle: AppHandle<R>,
    mut pending: PendingWindow<EventLoopMessage, R>,
    window_labels: &[String],
    web_resource_request_handler: Option<Box<WebResourceRequestHandler>>,
  ) -> crate::Result<PendingWindow<EventLoopMessage, R>> {
    if self.windows_lock().contains_key(&pending.label) {
      return Err(crate::Error::WindowLabelAlreadyExists(pending.label));
    }
    #[allow(unused_mut)] // mut url only for the data-url parsing
    let (is_local, mut url) = match &pending.webview_attributes.url {
      WindowUrl::App(path) => {
        let url = self.get_url();
        (
          true,
          // ignore "index.html" just to simplify the url
          if path.to_str() != Some("index.html") {
            url
              .join(&path.to_string_lossy())
              .map_err(crate::Error::InvalidUrl)
              // this will never fail
              .unwrap()
          } else {
            url.into_owned()
          },
        )
      }
      WindowUrl::External(url) => {
        let config_url = self.get_url();
        (config_url.make_relative(url).is_some(), url.clone())
      }
      _ => unimplemented!(),
    };

    #[cfg(not(feature = "window-data-url"))]
    if url.scheme() == "data" {
      return Err(crate::Error::InvalidWindowUrl(
        "data URLs are not supported without the `window-data-url` feature.",
      ));
    }

    #[cfg(feature = "window-data-url")]
    if let Some(csp) = self.csp() {
      if url.scheme() == "data" {
        if let Ok(data_url) = data_url::DataUrl::process(url.as_str()) {
          let (body, _) = data_url.decode_to_vec().unwrap();
          let html = String::from_utf8_lossy(&body).into_owned();
          // naive way to check if it's an html
          if html.contains('<') && html.contains('>') {
            let mut document = tauri_utils::html::parse(html);
            tauri_utils::html::inject_csp(&mut document, &csp.to_string());
            url.set_path(&format!("text/html,{}", document.to_string()));
          }
        }
      }
    }

    pending.url = url.to_string();

    if !pending.window_builder.has_icon() {
      if let Some(default_window_icon) = self.inner.default_window_icon.clone() {
        pending.window_builder = pending
          .window_builder
          .icon(default_window_icon.try_into()?)?;
      }
    }

    if pending.window_builder.get_menu().is_none() {
      if let Some(menu) = &self.inner.menu {
        pending = pending.set_menu(menu.clone());
      }
    }

    if is_local {
      let label = pending.label.clone();
      pending = self.prepare_pending_window(
        pending,
        &label,
        window_labels,
        app_handle.clone(),
        web_resource_request_handler,
      )?;
      pending.ipc_handler = Some(self.prepare_ipc_handler(app_handle));
    }

    // in `Windows`, we need to force a data_directory
    // but we do respect user-specification
    #[cfg(any(target_os = "linux", target_os = "windows"))]
    if pending.webview_attributes.data_directory.is_none() {
      let local_app_data = resolve_path(
        &self.inner.config,
        &self.inner.package_info,
        self.inner.state.get::<crate::Env>().inner(),
        &self.inner.config.tauri.bundle.identifier,
        Some(BaseDirectory::LocalData),
      );
      if let Ok(user_data_dir) = local_app_data {
        pending.webview_attributes.data_directory = Some(user_data_dir);
      }
    }

    // make sure the directory is created and available to prevent a panic
    if let Some(user_data_dir) = &pending.webview_attributes.data_directory {
      if !user_data_dir.exists() {
        create_dir_all(user_data_dir)?;
      }
    }

    Ok(pending)
  }

pub fn try_get<T: Send + Sync + 'static>(&self) -> Option<State<'_, T>>

Gets the state associated with the specified type.

Examples found in repository

src/lib.rs (line 758)

  fn state<T>(&self) -> State<'_, T>
  where
    T: Send + Sync + 'static,
  {
    self
      .manager()
      .inner
      .state
      .try_get()
      .expect("state() called before manage() for given type")
  }

  /// Attempts to retrieve the managed state for the type `T`.
  ///
  /// Returns `Some` if the state has previously been [managed](Self::manage). Otherwise returns `None`.
  fn try_state<T>(&self) -> Option<State<'_, T>>
  where
    T: Send + Sync + 'static,
  {
    self.manager().inner.state.try_get()
  }

src/state.rs (line 50)

  fn from_command(command: CommandItem<'de, R>) -> Result<Self, InvokeError> {
    Ok(command.message.state_ref().try_get().unwrap_or_else(|| {
      panic!(
        "state not managed for field `{}` on command `{}`. You must call `.manage()` before using this command",
        command.key, command.name
      )
    }))
  }

Trait Implementations

impl Debug for StateManager

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.