The nsIPrefLocalizedString interface is simply a wrapper interface for nsISupportsString so the preferences service can have a unique identifier to distinguish between requests for normal wide strings (nsISupportsString) and "localized" wide strings, which get their default values from properites files.
This interface is implemented by the following components:
Provides access to string data stored in this property.
Used to set the contents of this object.
- length: The length of the string. This value should not include space for the null terminator, nor should it account for the size of a character. It should only be the number of characters for which there is space in the string.
- data: The string data to be stored.
- NS_OK The data was successfully stored.
Used to retrieve the contents of this object into a wide string.
- wstring The string containing the data stored within this object.
Reference documentation is generated from Mozilla's source.