feat:add Provider ts

js-framework/src/util/provider.ts

@@ -0,0 +1,99 @@
+/*
+ * Copyright [2019] [Doric.Pub]
+ *
+ * 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.
+ */
+export type Observer<T> = (v: T) => void
+export type Updater<T> = (v: T) => T
+
+export interface IObservable<T> {
+
+    addObserver(observer: Observer<T | undefined>): void
+
+    removeObserver(observer: Observer<T | undefined>): void
+
+    update(updater: Updater<T | undefined>): void
+}
+
+export class Observable<M> implements IObservable<M>{
+    private provider: IProvider
+
+    private clz: { new(...args: any[]): M }
+
+    private observers: Set<Observer<M | undefined>> = new Set
+    constructor(provider: IProvider, clz: { new(...args: any[]): M }) {
+        this.provider = provider
+        this.clz = clz
+    }
+
+    addObserver(observer: Observer<M | undefined>): void {
+        this.observers.add(observer)
+    }
+
+    removeObserver(observer: Observer<M | undefined>): void {
+        this.observers.delete(observer)
+    }
+
+    update(updater: Updater<M | undefined>): void {
+        const oldV = this.provider.acquire(this.clz)
+        const newV = updater(oldV)
+        if (newV !== undefined) {
+            this.provider.provide(newV)
+        }
+        for (let observer of this.observers) {
+            observer(newV)
+        }
+    }
+}
+
+
+export interface IProvider {
+    provide(obj: Object): void
+    acquire<T>(clz: { new(...args: any[]): T }): T | undefined
+    remove<T>(clz: { new(...args: any[]): T }): void
+    clear(): void
+    observe<T>(clz: { new(...args: any[]): T }): Observable<T>
+}
+
+export class Provider implements IProvider {
+
+    private provision: Map<Function, Object> = new Map
+    private observableMap: Map<Function, Observable<any>> = new Map
+
+    provide(obj: Object) {
+        this.provision.set(obj.constructor, obj)
+    }
+
+    acquire<T>(clz: { new(...args: any[]): T }): T | undefined {
+        const ret = this.provision.get(clz)
+        return ret as T | undefined
+    }
+
+    remove<T>(clz: new (...args: any[]) => T): void {
+        this.provision.delete(clz)
+    }
+
+    clear(): void {
+        this.provision.clear()
+    }
+
+    observe<T>(clz: new (...args: any[]) => T): Observable<T> {
+        let observable = this.observableMap.get(clz)
+        if (observable === undefined) {
+            observable = new Observable(this, clz)
+            this.observableMap.set(clz, observable)
+        }
+        return observable
+    }
+}
+