CombineWrapper

public final class CombineWrapper : WebcomWrapper, CustomDebugStringConvertible

The type that wraps DatasyncManager in order to enrich it with a Combine-based API.

See also the documentation section of WebcomWrapper for the corresponding wrapped type.

To use this type, import the following dependency in your code:

import WebcomCombine

Stored Properties

API

  • Returns a reference to a database node.

    This method only returns nil when the path is ill-formed, that is when it contains forbidden characters. All nodes always exists: this method always returns a plain node reference when the path is syntactically valid. From a theoretical point of view, the concept on existence is a nonsense. From a practical point of view, we can consider that a node exists when its value is not null (the JSON null value, not to be confused with the Swift nil keyword).

    Creating a node reference is an extremely light-weight operation, so as many as desired can be created without worrying about wasting bandwidth or memory. It is possible to create several references for the same path. Each piece of code should declare the references it needs, without trying to factorize or cache anything.

    The path consists of segments separated by / (slash) characters. Each segment corresponds to a move in the database tree:

    • The starting point is the root node of the database tree
    • The . segment is a no-operation.
    • The .. segment indicates to go one level up in the tree. When already at the root node, this is a no-operation.
    • The empty segment, when using a / at the beginning or at the end of the path, or when using several consecutive /, is a no-operation.
    • Any other valid segment indicates to go one level down towards the so-named child.

    Examples:

    • If path is equal to foo, /foo, foo/ or /foo/, the path of the resulting node is /foo.
    • If path is equal to foo/bar, /foo/./bar or foo/geek/../bar/, the path of the resulting node is /foo/bar.
    • If path is equal to foo/bar/../geek/noob or /foo/bar/../geek/noob/. or foo//bar/../geek/./noob/., the path of the resulting node is /foo/geek/noob.

    • If path is equal to foo/..//.., the resulting node is the root node.

    Declaration

    Swift

    public func node(for path: String) -> DatasyncNode.CombineWrapper?

    Parameters

    path

    The absolute path of the node to refer. It can start or not with a / (slash) character. It is always absolute.

    Return Value

    A reference to the node corresponding to the path when the path is valid, nil otherwise.

  • Returns a reference to the database root node.

    Declaration

    Swift

    public var rootNode: DatasyncNode.CombineWrapper? { get }

  • Returns a reference to a database node.

    This operator returns:

    manager.node(for: path)

    Declaration

    Swift

    public static func / (manager: CombineWrapper, path: String) -> DatasyncNode.CombineWrapper?

    Parameters

    manager

    The manager to use to get the node reference.
    path

    The path of the node to refer.

    Return Value

    A reference to the node corresponding to the path when the path is valid, nil otherwise.

  • Creates a publisher that produces a DatasyncState value each time the state of the web socket changes.

    Subscriptions made with the returned publisher must be stored explicitly to remain active, e.g. using the AnyCancellable.store(in:) method. Unlike callback-based subscriptions made with the DatasyncManager.subscribeToStateChange(stores:file:line:queue:onChange:onCompletion:) method, these subscriptions are not stored implicitly.

    Declaration

    Swift

    public func statePublisher(file: StaticString = #fileID, line: UInt = #line) -> AnyPublisher<DatasyncState, Never>

    Return Value

    A type-erased publisher that produces DatasyncState values and never fails.

  • Creates a publisher that produces a value each time user currently authenticated on the web socket changes.

    Subscriptions made with the returned publisher must be stored explicitly to remain active, e.g. using the AnyCancellable.store(in:) method. Unlike callback-based subscriptions made with the DatasyncManager.subscribeToCurrentUIDChange(stores:file:line:queue:onChange:onCompletion:) method, these subscriptions are not stored implicitly.

    Declaration

    Swift

    public func currentUIDPublisher(file: StaticString = #fileID, line: UInt = #line) -> AnyPublisher<String?, Never>

    Return Value

    A type-erased publisher that produces user identifiers and never fails.

  • Removes all AnyCancellable instances stored in this manager.

    These instances were stored using the AnyCancellable.store(in:) method.

    If this manager stored the last reference to an AnyCancellableinstance, then this one will be cancelled, since the AnyCancellable deinitializer calls the Cancellable.cancel() method.

    Usually, there is no need to call this method since it is done automatically when this manager is deinitialized.

    Declaration

    Swift

    public func removeAllAnyCancellable()

Helpers

  • Gets the value of the node at a given path.

    Declaration

    Swift

    public func decodedValue<T>(at path: String) -> WebcomFuture<T> where T : Decodable

    Parameters

    path

    The path of the node whose value must be returned.

    Return Value

    A future with the decoded value of the node at the path.

  • decodedValue(at:) Asynchronous

    Declaration

    Swift

    public func decodedValue<T>(at path: String) async throws -> T where T : Decodable

  • Clears the value of the node at a given path.

    Declaration

    Swift

    @discardableResult
public func clear(at path: String) -> WebcomFuture<Void>

    Parameters

    path

    The path of the node whose value must be cleared.

    Return Value

    A future with a void value.

  • clear(at:) Asynchronous

    Declaration

    Swift

    public func clear(at path: String) async throws

  • Sets the value of the node at a given path.

    All children of the referred node cleared before setting the new value.

    Declaration

    Swift

    @discardableResult
public func set(_ value: (some Encodable)?, at path: String) -> WebcomFuture<Void>

    Parameters

    value

    The value to set. It will be encoded to JSON before being sent to the back-end, using the jsonDecoder of the WebcomApplication from which this manager derives. The null value can be specified with nil or NSNull().
    path

    The path of the node whose value must be set.

    Return Value

    A future with a void value.

  • set(_:at:) Asynchronous

    Declaration

    Swift

    public func set(_ value: (some Encodable)?, at path: String) async throws

  • Merges a value with the current value of the node at a given path.

    Unlike what happens with the set(_:at:):

    • value may not be nil,
    • the encoding of value to JSON must give a JSON object (or a JSON array but this is discouraged), or the method will fail,

    • existing direct children (i.e. the descendants at the first level of depth) that exist in the current value are preserved when value does not specify them.

    Declaration

    Swift

    @discardableResult
public func merge(with value: some Encodable, at path: String) -> WebcomFuture<Void>

    Parameters

    value

    The value to merge with. It will be encoded to JSON before being sent to the back-end, using the WebcomApplication.jsonEncoder of the WebcomApplication from which this node derives.
    path

    The path of the node whose value must be set.

    Return Value

    A future with a void value.

  • merge(with:at:) Asynchronous

    Declaration

    Swift

    public func merge(with value: some Encodable, at path: String) async throws

  • Adds a new child with the given value to the node at a given path.

    Declaration

    Swift

    @discardableResult
public func push(_ value: (some Encodable)?, at path: String) -> WebcomFuture<DatasyncNode.CombineWrapper>

    Parameters

    value

    The value to set for the created child. It will be encoded to JSON before being sent to the back-end, using the jsonDecoder of the WebcomApplication from which this manager derives. The null value can be specified with nil or NSNull().
    path

    The path of the node to which a child must be added.

    Return Value

    A future with the new child.

  • push(_:at:) Asynchronous

    Declaration

    Swift

    public func push(_ value: (some Encodable)?, at path: String) async throws -> DatasyncNode.CombineWrapper

CustomDebugStringConvertible Protocol

  • Declaration

    Swift

    public var debugDescription: String { get }