diff options
author | herbert <herbert.eiselt@highstreet-technologies.com> | 2019-12-14 01:05:47 +0100 |
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committer | Herbert Eiselt <herbert.eiselt@highstreet-technologies.com> | 2019-12-16 12:52:11 +0000 |
commit | e6d0d67fdbe3fc70c996c8df33bd65d3b151dfad (patch) | |
tree | 0d2da7d1da74c6ebca6b53039741617d35f65d96 /sdnr/wt/odlux/framework/src/flux/middleware.ts | |
parent | 6b98928b7b1b0ebc28d2ef286e8c932fca67c305 (diff) |
update odlux and featureaggregator
v2 update odlux and featureaggregator bundles
Issue-ID: SDNC-1008
Signed-off-by: herbert <herbert.eiselt@highstreet-technologies.com>
Change-Id: I0018d7bfa3a0e6896c1b210b539a574af9808e22
Signed-off-by: herbert <herbert.eiselt@highstreet-technologies.com>
Diffstat (limited to 'sdnr/wt/odlux/framework/src/flux/middleware.ts')
-rw-r--r-- | sdnr/wt/odlux/framework/src/flux/middleware.ts | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/sdnr/wt/odlux/framework/src/flux/middleware.ts b/sdnr/wt/odlux/framework/src/flux/middleware.ts new file mode 100644 index 000000000..de6505c4f --- /dev/null +++ b/sdnr/wt/odlux/framework/src/flux/middleware.ts @@ -0,0 +1,107 @@ +/** + * ============LICENSE_START======================================================================== + * ONAP : ccsdk feature sdnr wt odlux + * ================================================================================================= + * Copyright (C) 2019 highstreet technologies GmbH Intellectual Property. All rights reserved. + * ================================================================================================= + * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except + * in compliance with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software distributed under the License + * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express + * or implied. See the License for the specific language governing permissions and limitations under + * the License. + * ============LICENSE_END========================================================================== + */ +import { Action, IActionHandler } from './action'; +import { Store, Dispatch, Enhancer } from './store'; + +export interface MiddlewareArg<T> { + dispatch: Dispatch; + getState: () => T; +} + +export interface Middleware<T> { + (obj: MiddlewareArg<T>): Function; +} + +class InitialisationAction extends Action { }; +const initialisationAction = new InitialisationAction(); + +export type ActionHandlerMapObject<S extends { [key: string]: any }, A extends Action = Action> = { + [K in keyof S]: IActionHandler<S[K], A> +} + +export const combineActionHandler = <TState extends { [key: string]: any }, TAction extends Action = Action>(actionHandlers: ActionHandlerMapObject<TState, TAction>) : IActionHandler<TState, TAction> => { + const finalActionHandlers = {} as { [key: string]: any }; // https://github.com/microsoft/TypeScript/issues/31808 + Object.keys(actionHandlers).forEach(actionHandlerKey => { + const handler = actionHandlers[actionHandlerKey]; + if (typeof handler === 'function') { + finalActionHandlers[actionHandlerKey] = handler; + } + }); + + // ensure initialisation + Object.keys(finalActionHandlers).forEach(key => { + const actionHandler = finalActionHandlers[key]; + const initialState = actionHandler(undefined, initialisationAction); + if (typeof initialState === 'undefined') { + const errorMessage = `Action handler ${ key } returned undefiend during initialization.`; + throw new Error(errorMessage); + } + }); + + return function combination<TAction extends Action>(state: TState = ({} as TState), action: TAction) { + let hasChanged = false; + const nextState = {} as { [key: string]: any }; // https://github.com/microsoft/TypeScript/issues/31808 + Object.keys(finalActionHandlers).forEach(key => { + const actionHandler = finalActionHandlers[key]; + const previousState = state[key]; + const nextStateKey = actionHandler(previousState, action); + if (typeof nextStateKey === 'undefined') { + const errorMessage = `Given ${ action.constructor } and action handler ${ key } returned undefiend.`; + throw new Error(errorMessage); + } + nextState[key] = nextStateKey; + hasChanged = hasChanged || nextStateKey !== previousState; + }); + return (hasChanged ? nextState : state) as TState; + }; +}; + +export const chainMiddleware = <TStoreState>(...middlewares: Middleware<TStoreState>[]): Enhancer<TStoreState> => { + return (store: Store<TStoreState>) => { + const middlewareAPI = { + getState() { return store.state }, + dispatch: <TAction extends Action>(action: TAction) => store.dispatch(action) // we want to use the combinded dispatch + // we should NOT use the flux dispatcher here, since the action would affect ALL stores + }; + const chain = middlewares.map(middleware => middleware(middlewareAPI)); + return compose(...chain)(store.dispatch) as Dispatch; + } +}; + +/** + * Composes single-argument functions from right to left. The rightmost + * function can take multiple arguments as it provides the signature for + * the resulting composite function. + * + * @param {...Function} funcs The functions to compose. + * @returns {Function} A function obtained by composing the argument functions + * from right to left. For example, compose(f, g, h) is identical to doing + * (...args) => f(g(h(...args))). + */ +const compose = (...funcs: Function[]) => { + if (funcs.length === 0) { + return (arg: any) => arg + } + + if (funcs.length === 1) { + return funcs[0] + } + + return funcs.reduce((a, b) => (...args: any[]) => a(b(...args))); +}; + |