101 lines
3.5 KiB
Swift
101 lines
3.5 KiB
Swift
//
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// Copyright (c) 2018 Touch Instinct
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the Software), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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//
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/// Enum that contains states for paginated data loading.
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///
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/// - initial: Initial state. Before something will happen.
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/// - initialLoading: Initial loading state. When data was requested initially.
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/// - loadingMore: Loading more state. When additional data was requested.
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/// - results: Result state from a specific data source after a given state.
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/// - error: Error state with a specific error after a given state.
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/// - empty: Empty state. When data was initially requested and empty result was received.
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/// - exhausted: Exhausted state. When no more results can be received.
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public indirect enum PaginationDataLoadingState<DS: DataSource> {
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case initial
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case initialLoading(after: PaginationDataLoadingState)
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case loadingMore(after: PaginationDataLoadingState)
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case results(newItems: DS.ResultType, from: DS, after: PaginationDataLoadingState)
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case error(error: Error, after: PaginationDataLoadingState)
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case empty
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case exhausted
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}
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extension PaginationDataLoadingState: DataLoadingState {
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public typealias DataSourceType = DS
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public static var initialState: PaginationDataLoadingState<DS> {
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return .initial
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}
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public static var emptyState: PaginationDataLoadingState<DS> {
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return .empty
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}
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public static func initialLoadingState(after: PaginationDataLoadingState<DS>) -> PaginationDataLoadingState<DS> {
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return .initialLoading(after: after)
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}
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public static func resultState(result: DS.ResultType,
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from: DataSourceType,
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after: PaginationDataLoadingState<DS>) -> PaginationDataLoadingState<DS> {
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return .results(newItems: result, from: from, after: after)
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}
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public static func errorState(error: Error,
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after: PaginationDataLoadingState<DS>) -> PaginationDataLoadingState<DS> {
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return .error(error: error, after: after)
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}
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public var isInitialState: Bool {
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switch self {
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case .initial:
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return true
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default:
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return false
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}
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}
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public var result: DS.ResultType? {
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switch self {
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case .results(let newItems, _, _):
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return newItems
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default:
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return nil
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}
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}
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public var error: Error? {
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switch self {
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case .error(let error, _):
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return error
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default:
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return nil
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}
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}
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}
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