Trait preferences::Preferences [−] [src]

pub trait Preferences {
    fn save<S>(&self, path: S) -> Result<(), PreferencesError> where S: AsRef<str>;
    fn load<S>(&mut self, path: S) -> Result<(), PreferencesError> where S: AsRef<str>;
    fn save_to<W>(&self, writer: &mut W) -> Result<(), PreferencesError> where W: Write;
    fn load_from<R>(&mut self, reader: &mut R) -> Result<(), PreferencesError> where R: Read;
}

Trait for types that can be saved & loaded as user data.

This type is automatically implemented for any type T which implements both Encodable and Decodable (from rustc-serialize). However, you are encouraged to use the provided type, PreferencesMap.

The path parameter of save(..) and load(..) should be a valid, relative file path. It is highly recommended that you use the format [company or author]/[application name]/[data description]. For example, a game might use the following paths for player options and save data, respectively:

  • fun-games-inc/awesome-game-2/options
  • fun-games-inc/awesome-game-2/saves

Required Methods

fn save<S>(&self, path: S) -> Result<(), PreferencesError> where S: AsRef<str>

Saves the current state of this object. Implementation is platform-dependent, but the data will be local to the active user. For more details, see the module documentation.

Failures

If a serialization or file I/O error occurs (e.g. permission denied), or if the provided path argument is invalid.

fn load<S>(&mut self, path: S) -> Result<(), PreferencesError> where S: AsRef<str>

Loads this object's state from previously saved user data with the same path. This is an instance method which completely overwrites the object's state with the serialized data. Thus, it is recommended that you call this method immediately after instantiating the preferences object.

Failures

If a deserialization or file I/O error occurs (e.g. permission denied), if the provided path argument is invalid, or if no user data exists at that path.

fn save_to<W>(&self, writer: &mut W) -> Result<(), PreferencesError> where W: Write

Same as save, but writes the serialized preferences to an arbitrary writer.

fn load_from<R>(&mut self, reader: &mut R) -> Result<(), PreferencesError> where R: Read

Same as load, but reads the serialized preferences from an arbitrary writer.

Implementors