YapWhitelistBlacklist

@interface YapWhitelistBlacklist : NSObject

This class provides a standardized way to create a sort of whitelist / blacklist. It is used often within the options of extensions to create the set of allowedCollections.

  • Creates a whitelist based instance.

    Only items in the whitelist are allowed. Any items not in the whitelist are disallowed.

    Declaration

    Objective-C

    - (nonnull instancetype)initWithWhitelist:(nullable NSSet *)whitelist;

    Swift

    init(whitelist: Set<AnyHashable>?)

  • Creates a blacklist based instance.

    Only items in the blacklist are disallowed. Any items not in the blacklist are allowed.

    Declaration

    Objective-C

    - (nonnull instancetype)initWithBlacklist:(nullable NSSet *)blacklist;

    Swift

    init(blacklist: Set<AnyHashable>?)

  • Creates a filterBlock based instance.

    Rather than a known whitelist/blacklist, the filterBlock makes it possible to use app-specific criteria. For example, using prefix matching, regular expressions, etc.

    When creating your block, you must keep in mind 2 things:

    1.) YapDatabase extensions may invoke the filterBlock from background threads durind readWriteTransactions. Thus your filterBlock MUST be thread-safe.

    2.) The filterBlock is expected to be IMMUTABLE. That is, if the fitlerBlock is invoked with item X, and the filterBlock returns YES, then the filterBlock must always return YES for X. It should not change its mind about X.

    If the filterBlock returns YES for a given item, that item is allowed. If the filterBlock returns NO for a given item, that item is disallowed.

    Declaration

    Objective-C

    - (nonnull instancetype)initWithFilterBlock:
    (nullable YapWhitelistBlacklistFilterBlock)block;

    Swift

    init(filterBlock block: YapWhitelistBlacklistFilterBlock? = nil)

  • Inspects the whitelist or blacklist, or consults the filterBlock (depending on initialization), and returns whether or not the item is allowed.

    Declaration

    Objective-C

    - (BOOL)isAllowed:(nonnull id)item;

    Swift

    func isAllowed(_ item: Any) -> Bool