src/id-handler.js

"use strict";

module.exports = function(options) {
    var idGenerator     = options.idGenerator;
    var getState        = options.stateHandler.getState;

    /**
     * Gets the resize detector id of the element.
     * @public
     * @param {element} element The target element to get the id of.
     * @returns {string|number|null} The id of the element. Null if it has no id.
     */
    function getId(element) {
        var state = getState(element);

        if (state && state.id !== undefined) {
            return state.id;
        }

        return null;
    }

    /**
     * Sets the resize detector id of the element. Requires the element to have a resize detector state initialized.
     * @public
     * @param {element} element The target element to set the id of.
     * @returns {string|number|null} The id of the element.
     */
    function setId(element) {
        var state = getState(element);

        if (!state) {
            throw new Error("setId required the element to have a resize detection state.");
        }

        var id = idGenerator.generate();

        state.id = id;

        return id;
    }

    return {
        get: getId,
        set: setId
    };
};