Policy enum

Caching policies that determine how Syncache.get retrieves data.

Each policy defines a different strategy for balancing between cached data and fresh network fetches.

Inheritance
Available extensions

Values

offlineFirst → const Policy

Returns cached data if available and not expired; fetches otherwise.

This is the default policy and provides the best offline-first experience. The cache is checked first, and network requests are only made when necessary.

Behavior:

  1. If valid (non-expired) cache exists, return it immediately
  2. If online, attempt to fetch fresh data
  3. If fetch fails but stale cache exists, return stale data
  4. If no cache and offline/fetch fails, throw CacheMissException
cacheOnly → const Policy

Returns only cached data; never makes network requests.

Use this policy when you want to ensure no network activity, such as displaying data that was pre-fetched earlier.

Throws CacheMissException if no cached data exists.

networkOnly → const Policy

Always fetches from network; ignores cached data.

Use this policy when you need guaranteed fresh data and network availability is certain.

Throws if the network request fails.

refresh → const Policy

Fetches from network if online; falls back to cache if offline.

Similar to offlineFirst but always prefers fresh data when online, regardless of cache validity.

Behavior:

  1. If online, fetch from network
  2. If offline, return cached data
  3. If offline with no cache, throw CacheMissException
staleWhileRefresh → const Policy

Returns cached data immediately; refreshes in background if expired.

This policy provides the fastest perceived performance by always returning cached data first, then updating the cache asynchronously. Subscribers via Syncache.watch will receive the updated value.

Behavior:

  1. If cache exists, return it immediately
  2. If cache is expired and online, trigger background refresh
  3. If no cache exists and online, fetch and return
  4. If no cache and offline, throw CacheMissException

Properties

hashCode → int
The hash code for this object.
no setterinherited
index → int
A numeric identifier for the enumerated value.
no setterinherited
name → String

Available on Enum, provided by the EnumName extension

The name of the enum value.
no setter
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Constants

values → const List<Policy>
A constant List of the values in this enum, in order of their declaration.