Struct ConfigManager 

pub struct ConfigManager<T> { /* private fields */ }

Manages one typed JSON settings file.

ConfigManager<T> stores and loads a complete configuration value of type T. The type must implement Serde Serialize and DeserializeOwned.

The manager is intentionally small. It owns only:

• the directory containing the settings file,
• the settings file name, and
• the JSON output format.

Implementations

impl<T> ConfigManager<T>

where T: Serialize + DeserializeOwned,

pub fn new() -> Self

Creates a config manager using the OS-standard config directory and the current executable name.

On Windows desktop apps this resolves under %APPDATA%. Pure UWP apps should use with_root_dir or the optional uwp feature instead.

For production applications, prefer for_app because it uses an explicit stable application identity instead of deriving one from the executable file name.

pub fn for_app(app_name: &str) -> Result<Self>

Creates a config manager for an explicit application name.

This is the recommended desktop constructor for production apps because the storage directory is stable even if the executable file name changes. The app_name must be a single safe path component, not a path.

pub fn at_current_dir(self) -> Self

Stores the settings file in the current working directory.

pub fn with_root_dir<P: Into<PathBuf>>(self, path: P) -> Self

Stores the settings file in a caller-provided directory.

This is the primary compatibility seam for sandboxed hosts, including Pure UWP. The host application may resolve its application data directory and pass it here.

pub fn at_custom_dir<P: Into<PathBuf>>(self, path: P) -> Self

Stores the settings file in a caller-provided directory.

This method is kept for compatibility with v2.0.x. Prefer with_root_dir in new code.

pub fn with_filename(self, name: &str) -> Self

Changes the settings file name without validation.

This method is retained for v2.x compatibility. New code should prefer try_with_filename, which rejects path-like names such as ../settings.json.

pub fn try_with_filename(self, name: &str) -> Result<Self>

Changes the settings file name after validating it as a plain file name.

The accepted value must be a single file name, not an absolute path and not a relative path containing directory traversal.

pub fn disable_pretty_json(self) -> Self

Stores JSON in compact form instead of pretty-printed form.

pub fn folder_path(&self) -> &Path

Returns the settings folder path.

pub fn file_name(&self) -> &str

Returns the settings file name.

pub fn path(&self) -> PathBuf

Returns the settings file path.

pub fn save(&self, config: &T) -> Result<()>

Saves the complete configuration, replacing the existing file content.

pub fn load(&self) -> Result<T>

Loads a configuration file that is expected to already exist.

impl<T> ConfigManager<T>

where T: Serialize + DeserializeOwned + Default,

pub fn load_or_default(&self) -> Result<T>

Loads the configuration, or creates and saves T::default() on first run.

pub fn update<F>(&self, f: F) -> Result<T>

where F: FnOnce(&mut T),

Applies a read-modify-write update and saves the result.

Trait Implementations

impl<T: Clone> Clone for ConfigManager<T>

fn clone(&self) -> ConfigManager<T>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for ConfigManager<T>

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

Formats the value using the given formatter.

impl<T> Default for ConfigManager<T>

where T: Serialize + DeserializeOwned,

fn default() -> Self

Returns the “default value” for a type.