dio_cache_interceptor

Description:

dio cache interceptor

Dio HTTP cache interceptor with multiple stores respecting HTTP directives (or not).
HTTP directives: #









Cache triggers
ETag



Last-Modified



Date


Cache freshness
Age



Date



Expires



max-age (Cache-Control)



max-stale (Cache-Control)



min-fresh (Cache-Control)



must-revalidate



Request date (added by interceptor)



Response date (added by interceptor)


Cache commutators
no-cache (Cache-Control)



no-store (Cache-Control request & response)



Stores #

BackupCacheStore: Combined store with primary and secondary.
DbCacheStore: Cache with database (Drift) Get it.
FileCacheStore: Cache with file system (Does nothing on web platform) Get it.
HiveCacheStore: Cache using Hive package (available on all platforms) Get it.
IsarCacheStore: Cache using Isar package (available on all platforms) Get it.
ObjectBoxCacheStore: Cache using ObjectBox package (no web support) Get it.
SembastCacheStore: Cache using Sembast package Get it.
MemCacheStore: Volatile cache with LRU strategy.

Usage #
import 'package:dio_cache_interceptor/dio_cache_interceptor.dart';

// Global options
final options = const CacheOptions(
// A default store is required for interceptor.
store: MemCacheStore(),

// All subsequent fields are optional.

// Default.
policy: CachePolicy.request,
// Returns a cached response on error but for statuses 401 & 403.
// Also allows to return a cached response on network errors (e.g. offline usage).
// Defaults to [null].
hitCacheOnErrorExcept: [401, 403],
// Overrides any HTTP directive to delete entry past this duration.
// Useful only when origin server has no cache config or custom behaviour is desired.
// Defaults to [null].
maxStale: const Duration(days: 7),
// Default. Allows 3 cache sets and ease cleanup.
priority: CachePriority.normal,
// Default. Body and headers encryption with your own algorithm.
cipher: null,
// Default. Key builder to retrieve requests.
keyBuilder: CacheOptions.defaultCacheKeyBuilder,
// Default. Allows to cache POST requests.
// Overriding [keyBuilder] is strongly recommended when [true].
allowPostMethod: false,
);

// Add cache interceptor with global/default options
final dio = Dio()..interceptors.add(DioCacheInterceptor(options: options));

// ...

// Requesting with global options => status(200) => Content is written to cache store
var response = await dio.get('https://www.foo.com');
// Requesting with global options => status(304) => Content is read from cache store
response = await dio.get('https://www.foo.com');

// Requesting by modifying policy with refresh option
// for this single request => status(200) => Content is written to cache store
response = await dio.get('https://www.foo.com',
options: options.copyWith(policy: CachePolicy.refresh).toOptions(),
);
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Handling cache with client only #
Follow those intructions if needed.
Options #
CacheOptions is widely available on interceptor and on requests to take precedence.
See documentation for all properties.
Encryption #
Optionally, you can encrypt body and headers with your own algorithm via CacheCipher.
Cache policy #
enum CachePolicy {
/// Same as [CachePolicy.request] when origin server has no cache config.
///
/// In short, you'll save every successful GET requests.
forceCache,

/// Same as [CachePolicy.refresh] when origin server has no cache config.
refreshForceCache,

/// Requests and skips cache save even if
/// response has cache directives.
noCache,

/// Requests regardless cache availability.
/// Caches if response has cache directives.
refresh,

/// Returns the cached value if available (and un-expired).
///
/// Checks against origin server otherwise and updates cache freshness
/// with returned headers when validation is needed.
///
/// Requests otherwise and caches if response has directives.
request,
}
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Features and bugs #
Please file feature requests and bugs at the issue tracker.
License #
License.