RVS_PersistentPrefs

public class RVS_PersistentPrefs : NSObject

This class is designed to act as an abstract base class, providing a simple Dictionary datastore that is stored in the UserDefaults in the Application Bundle. It is designed to be reliable, and extremely simple to use. The stored Dictionary would be a String-keyed Dictionary of Any (flexible types). It s up to subclasses to specialize the typeless data. THIS IS NOT EFFICIENT OR ROBUST! It is meant as a simple bucket for things like application preferences. It is not an industrial data storage solution. You have been warned. Subclasses could declare their accessors as KVO-style, thus, providing a direct way to influence persistent state. You can also directly observe the .values property. It will change when ANY pref is changed (so might not be suitable for pick and choose observation).

Private Properties

  • This is the Dictionary. It’s private, and shouldn’t need to be accessed outside this base class.

    Declaration

    Swift

    private var _values: [String : Any]

Private Methods

  • This is a private method that saves the current contents of the _values Dictionary to persistent storage, keyed by the value of the key property.

    Throws

    An error, if the values are not all codable.

    Declaration

    Swift

    private func _save() throws

  • This is a private method that reads in the data from persistent storage for this instance (using the key property), and loads the _values Dictionary property.

    Throws

    An error, if there were no stored prefs for the given key.

    Declaration

    Swift

    private func _load() throws

Public Enums

  • Errors that Can be thrown from methods in this class

    See more

    Declaration

    Swift

    public enum PrefsError : Error

Public Properties
  • key

    This is the key that is used to store and fetch the collection of data to be used to populate the _values Dictionary.

    Declaration

    Swift

    public var key: String

  • This is any error that was thrown during a save or a load.

    Declaration

    Swift

    public var lastError: RVS_PersistentPrefs.PrefsError!

Public Calculated Properties

  • This calculated property MUST be overridden by subclasses. It is an Array of String, containing the keys used to store and retrieve the values from persistent storage.

    Declaration

    Swift

    public var keys: [String] { get }

  • This is an accessor for the _values Dictionary. Before it returns the Dictionary, it loads data from persistent storage. After it sets the Dictionary, it saves the resulting Dictionary to persistent storage. This is meant to make persistent storage completely transparent. You simply read and write the Dictionary, using these accessors. The saving and retrieving happens in the background.

    Declaration

    Swift

    @objc
dynamic public var values: [String : Any] { get set }

Public Subscript

  • Declaration

    Swift

    subscript(inKey: String) -> Any? { get set }

Initializers

  • The default initializer uses the current subclass typename as the main key.

    Declaration

    Swift

    public override init()

  • You can initialize instances with a key and some initial data values.

    Declaration

    Swift

    public init(key inKey: String! = nil, values inValues: [String : Any]! = [:])

    Parameters

    key

    Optional (default is nil). A String, with a key to be used to associate the persistent state of this object to storage in the bundle. If not provided, the subclass classname is used as the key.
    values

    Optional (default is nil). A Dictionary, with the values to be stored. If not provided, then the instance is populated by any persistent prefs. If provided, then the persistent prefs are updated with the new values.