TypeScript Source

/**
 * The agjVersionless jQuery plugin.
 *
 * Copyright (c) 2026 Andrew G. Johnson <andrew@andrewgjohnson.com>
 * 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.
 * @file The source code for the agjVersionless jQuery plugin.
 * @copyright 2026 Andrew G. Johnson <andrew@andrewgjohnson.com>
 * @license MIT
 * @see {@link https://github.com/andrewgjohnson/agjVersionless GitHub Repository}
 * @see {@link https://agjVersionless.agjjQuery.org/ Online Documentation}
 * @author Andrew G. Johnson <andrew@andrewgjohnson.com>
 * @version 1.0.0
 */

/// <reference types="jquery" />

interface JQueryStatic {
  agjVersionless: {
    bind(
      element: JQuery,
      event: string,
      data: JQuery.EventHandler<HTMLElement> | JQuery.PlainObject | undefined,
      fn?: JQuery.EventHandler<HTMLElement>,
    ): JQuery;
    unbind(element: JQuery, event: string): JQuery;
    on(
      element: JQuery,
      event: string,
      data: JQuery.EventHandler<HTMLElement> | JQuery.PlainObject | undefined,
      fn?: JQuery.EventHandler<HTMLElement>,
    ): JQuery;
    off(element: JQuery, event: string): JQuery;
  };
}

interface JQuery {
  agjVersionless: {
    bind(
      event: string,
      data: JQuery.EventHandler<HTMLElement> | JQuery.PlainObject | undefined,
      fn?: JQuery.EventHandler<HTMLElement>,
    ): JQuery;
    unbind(event: string): JQuery;
    on(
      event: string,
      data: JQuery.EventHandler<HTMLElement> | JQuery.PlainObject | undefined,
      fn?: JQuery.EventHandler<HTMLElement>,
    ): JQuery;
    off(event: string): JQuery;
  };
}

/**
 * The agjVersionless plugin is built entirely in an IIFE (immediately invoked
 * function expression) to avoid polluting the global namespace.
 * @param $ - A reference to the global jQuery object.
 */
(function ($: JQueryStatic) {
  'use strict';

  const jQueryMajorVersion: number = parseInt($.fn.jquery.split('.')[0], 10);

  /**
   * The versionlessBind() function will bind an event handler to an element
   * regardless of jQuery version.
   * @param element - The element to bind the event handler to.
   * @param event - The event to bind the event handler to.
   * @param data - Optional data to pass to the event handler or the event
   * handler itself if no data is passed.
   * @param fn - The event handler.
   * @returns Returns the element to allow for chaining.
   */
  const versionlessBind = (
    element: JQuery,
    event: string,
    data: JQuery.EventHandler<HTMLElement> | JQuery.PlainObject | undefined,
    fn?: JQuery.EventHandler<HTMLElement>,
  ): JQuery => {
    // the data field is optional so this will handle calls to
    // versionlessBind(element, event, fn)
    if (typeof data === 'function' && typeof fn === 'undefined') {
      fn = data as JQuery.EventHandler<HTMLElement>;
      data = undefined;
    }

    /* istanbul ignore next -- older jQuery versions aren’t available to test via command line */
    switch (jQueryMajorVersion) {
      /* istanbul ignore next -- older jQuery versions aren’t available to test via command line */
      case 1:
        if (data === undefined) {
          // eslint-disable-next-line @typescript-eslint/no-explicit-any
          return element.bind(event, fn as any);
        } else {
          // eslint-disable-next-line @typescript-eslint/no-explicit-any
          return element.bind(event, data, fn as any);
        }

      case 2:
      case 3:
      default:
        if (data === undefined) {
          // eslint-disable-next-line @typescript-eslint/no-explicit-any
          return element.on(event, fn as any);
        } else {
          // eslint-disable-next-line @typescript-eslint/no-explicit-any
          return element.on(event, data as JQuery.PlainObject, fn as any);
        }
    }
  };

  /**
   * The versionlessUnbind() function will unbind an event handler from an
   * element regardless of jQuery version.
   * @param element - The element to unbind the event handler from.
   * @param event - The event to unbind the event handler from.
   * @returns Returns the element to allow for chaining.
   */
  const versionlessUnbind = (element: JQuery, event: string): JQuery => {
    /* istanbul ignore next -- older jQuery versions aren’t available to test via command line */
    switch (jQueryMajorVersion) {
      /* istanbul ignore next -- older jQuery versions aren’t available to test via command line */
      case 1:
        return element.unbind(event);

      case 2:
      case 3:
      default:
        return element.off(event);
    }
  };

  /**
   * The $.agjVersionless object exposes the versionless functions as a jQuery
   * plugin namespace.
   */
  $.agjVersionless = {
    bind: versionlessBind,
    unbind: versionlessUnbind,
    on: versionlessBind,
    off: versionlessUnbind,
  };

  /**
   * The $.fn.agjVersionless getter exposes the versionless functions on
   * individual jQuery elements, allowing element.agjVersionless.bind() style
   * calls in addition to $.agjVersionless.bind(element) style calls.
   * The try/catch handles IE8 and below where Object.defineProperty either
   * does not exist or does not support plain objects like $.fn.
   */
  try {
    Object.defineProperty($.fn, 'agjVersionless', {
      get: function (this: JQuery) {
        return {
          bind: (
            event: string,
            data?: JQuery.EventHandler<HTMLElement> | JQuery.PlainObject,
            fn?: JQuery.EventHandler<HTMLElement>,
          ): JQuery => {
            return versionlessBind(this, event, data, fn);
          },
          unbind: (event: string): JQuery => {
            return versionlessUnbind(this, event);
          },
          on: (
            event: string,
            data?: JQuery.EventHandler<HTMLElement> | JQuery.PlainObject,
            fn?: JQuery.EventHandler<HTMLElement>,
          ): JQuery => {
            return versionlessBind(this, event, data, fn);
          },
          off: (event: string): JQuery => {
            return versionlessUnbind(this, event);
          },
        };
      },
    });
  } catch {
    // IE8 and below: element.agjVersionless is unavailable; use $.agjVersionless instead
  }
})(jQuery);