@geogirafe/lib-geoportal/base/GirafeSingleton.js

GeoGirafe is a flexible application to build online geoportals.

class GirafeSingleton {
    constructor(type) {
        if (!(type in GirafeSingleton.initializingSingletons) || !GirafeSingleton.initializingSingletons[type]) {
            throw new Error('This is a singleton. Please use the getInstance() method.');
        }
    }
    static getInstance() {
        const type = this.name;
        if (!(type in GirafeSingleton.instances)) {
            // Singleton do not exists
            // => create it
            GirafeSingleton.initializingSingletons[type] = true;
            try {
                // Get the child constructor, and create and instance of the child
                const singleton = new this(type);
                GirafeSingleton.instances[type] = singleton;
            }
            finally {
                GirafeSingleton.initializingSingletons[type] = false;
            }
        }
        return GirafeSingleton.instances[type];
    }
    isNullOrUndefined(val) {
        return val === undefined || val === null;
    }
    isNullOrUndefinedOrBlank(val) {
        return val === undefined || val === null || val === '';
    }
}
Object.defineProperty(GirafeSingleton, "instances", {
    enumerable: true,
    configurable: true,
    writable: true,
    value: {}
});
Object.defineProperty(GirafeSingleton, "initializingSingletons", {
    enumerable: true,
    configurable: true,
    writable: true,
    value: {}
});
export default GirafeSingleton;