Producer-consumer pattern implementation (send message on change status).

statusproducer.js

window.statusProducer = function (d, options) {

    var options = options || {},
        availableStatuses = options.statuses || {},
        dataKey = options.dataKey || ('statusData' + new Date().getTime());
        errorDialog = options.errorDialog || alert;

    return {

        addListener: function (status, callee) {
            if (typeof callee !== 'function')
                return errorDialog("тип слушателя может быть только \"function\"");
            availableStatuses[status] = callee;
        },

        addState: function (status) {
            if (!availableStatuses.hasOwnProperty(status))
                availableStatuses[status] = status;
        },

        setStatus: function (newStatus, content) {
            if (!availableStatuses.hasOwnProperty(newStatus))
                return errorDialog('статус "' + newStatus + '" неопределен');
            if (newStatus === this.getStatus())
                return;
            var statusValue = availableStatuses[newStatus];
            if (typeof statusValue === 'function') {
                statusValue(d, content, newStatus);
            }
            d.data(dataKey, { status: newStatus, content: content });
        },

        getStatus: function (key) {
            return (d.data(dataKey) || {})[key || 'status'];
        },

        getData: function () {
            return d.data();
        },

        hasStatus: function (test) {
            return test === this.getStatus();
        }

    }

};