minsky-kit/js/managers/BLManager.js

Kit of components for MINSKY web agency

// imports
import Core from '../core/Core';

// static properties

// class definition
export default class BLManager extends Core {
    // constructor
    constructor (args = {}, objectName = 'BL MGR') {
        super(args, objectName);

        this._listeners = {};
        this._scope = args.scope || this;
    }

    // methods
    add (name, listener, scope = null) {
        // check if array with name exists
        if (!Array.isArray(this._listeners[name])) this._listeners[name] = [];

        // create listener definition
        const listenerDefinition = {
            original:      listener,
            boundListener: listener.bind(scope || this._scope),
            scope:         scope || this._scope,
        };

        // add listener definition
        this._listeners[name].push(listenerDefinition);

        // return newly bound listener
        return listenerDefinition.boundListener;
    }

    addOnce (...args) {
        return this.get(...args) || this.add(...args);
    }

    get (name, listener = null, scope = null) {
        // grab specific listeners
        const list = this._listeners[name];

        if (list) {
            // check for definition that matches parameters & return bound listener
            const definition = findMatchingDefinition(list, listener, scope);
            if (definition) return definition.boundListener;
        }

        return null;
    }

    remove (name, listener = null, scope = null) {
        // grab specific listeners
        const list = this._listeners[name];

        if (list) {
            // check for definition that matches parameters & remove & return bound listener
            const definition = findMatchingDefinition(list, listener, scope);

            const index = list.indexOf(definition);
            if (index > -1) list.splice(index, 1);

            // if (!definition) debugger;

            return definition.boundListener;
        }

        return null;
    }

    destroy () {
        for (const p of Object.keys(this._listeners)) {
            this._listeners[p] = null;
        }

        super.destroy();
    }

    // getters & setters
}

// utils
function findMatchingDefinition (list, listener = null, scope = null) {
    if (listener) {
        return list.find((def) => (def.original === listener) && (!scope || def.scope === scope));
    }

    // use last adde assuming that's the one that would be requested most
    return list[list.length - 1];
}