fluence-js/src/subscriptions.ts

/*
 *   MIT License
 *
 *   Copyright (c) 2020 Fluence Labs Limited
 *
 *   Permission is hereby granted, free of charge, to any person obtaining a copy
 *   of this software and associated documentation files (the "Software"), to deal
 *   in the Software without restriction, including without limitation the rights
 *   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *   copies of the Software, and to permit persons to whom the Software is
 *   furnished to do so, subject to the following conditions:
 *
 *   The above copyright notice and this permission notice shall be included in all
 *   copies or substantial portions of the Software.
 *
 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 *   SOFTWARE.
 */

import {FunctionCall} from "./function_call";
import {Address} from "./address";

export class Subscriptions {
    private subscriptions: ((args: any, target: Address, replyTo: Address) => (boolean | undefined))[] = [];

    constructor() {}

    /**
     * Subscriptions will be applied to all peer and relay messages.
     * If subscription returns true, delete subscription.
     * @param f
     */
    subscribe(f: (args: any, target: Address, replyTo: Address) => (boolean | undefined)) {
        this.subscriptions.push(f);
    }

    /**
     * Apply call to all subscriptions and delete subscriptions that return `true`.
     * @param call
     */
    applyToSubscriptions(call: FunctionCall) {
        // if subscription return false - delete it from subscriptions
        this.subscriptions = this.subscriptions.filter(callback => !callback(call.arguments, call.target, call.reply_to))
    }
}