Settings and storage

WebRadioFM uses IsolatedStorageSettings.ApplicationSettings, a key/value dictionary scoped to the installed application.

Preference keys

Key	Type	Default	Setter behavior
ScrobblerEnabled	bool	true	Direct
NowPlayingEnabled	bool	true	Direct
ScrobbleDelaySecs	int	180	Clamped 30–360
ScrobbleDelayPercent	int	50	Clamped 30–95
MinTrackDuration	int	30	Clamped 10–60
FetchAlbumArt	bool	false	Direct
ThemeName	string	Default	Direct; theme lookup falls back
ThemeIsDark	bool	true	Direct
LoveOnStartup	bool	false	Direct
RegexRules	List<MetadataEditRule>	empty	Replaced as a list
BlockedTracks	List<string>	empty	Replaced as a list
SimpleEdits	List<MetadataEditRule>	empty	Replaced as a list

Every setter writes the value and calls Save() immediately inside a silent try/catch.

Session keys

LastFMService manages two additional keys:

Key	Type	Purpose
LastFmSessionKey	string	Authenticated Last.fm session
LastFmUsername	string	Account used for statistics

They are saved together after auth.getSession and removed together by ClearSession().

ApiKey and ApiSecret are not stored.

Read behavior

The generic helper is conceptually:

if (settings.Contains(key))
    return (T)settings[key];
return defaultValue;

All exceptions are caught and return the default. A stale value with the wrong runtime type therefore behaves as missing.

Getters do not normalize already-stored numeric values through the setter clamp. If isolated storage contains an out-of-range integer written by an older build or external tooling, the getter returns it directly.

Migration

UpgradeSettings() implements schema version 1:

The migration assumes the old key is a bool; an incompatible type could throw because this method has no surrounding catch. App calls it during construction.

Future migrations should compare an integer version and apply every intermediate step rather than only checking key presence.

Metadata rule persistence

MetadataEditRule has public properties and a parameterless constructor so isolated settings can serialize it. Fields are:

• Field
• Pattern
• Replacement
• Enabled
• Description

Settings UI creates rules with Enabled = true; transformation currently ignores Enabled and Description.

Storage lifecycle

• Page control changes save immediately for switches/sliders/themes.
• Multiline block/edit text saves only when its explicit button is tapped.
• App deactivation/closing does not run an additional flush.
• Package update generally retains settings.
• Uninstall generally removes isolated storage.

Failure visibility

Read/write/session exceptions are swallowed, so the UI can appear to save while persistence failed. In a diagnostic build, add logging or breakpoints inside catches without logging secret values.

Security posture

Isolated application settings are convenient persistence, not an application-managed encrypted vault. Session keys are sensitive. See Privacy and security.