io3fix/src/core/runtime/dom-ready.js

toolkit for interior apps

/**
 * @license RequireJS domReady 2.0.1 Copyright (c) 2010-2012, The Dojo Foundation All Rights Reserved.
 * Available via the MIT or new BSD license.
 * see: http://github.com/requirejs/domReady for details
 */

var isTop, testDiv, scrollIntervalId,
  isBrowser = typeof window !== "undefined" && window.document,
  isPageLoaded = !isBrowser,
  doc = isBrowser ? document : null,
  readyCalls = [];

var resolve, readyPromise = new Promise(function(resolve_){
  resolve = resolve_
})

function runCallbacks(callbacks) {
  var i;
  for (i = 0; i < callbacks.length; i += 1) {
    callbacks[i](doc);
  }
}

function callReady() {
  var callbacks = readyCalls;

  if (isPageLoaded) {
    //Call the DOM ready callbacks
    if (callbacks.length) {
      readyCalls = [];
      runCallbacks(callbacks);
    }
    // resolves promise
    resolve(doc)
  }
}

/**
 * Sets the page as loaded.
 */
function pageLoaded() {
  if (!isPageLoaded) {
    isPageLoaded = true;
    if (scrollIntervalId) {
      clearInterval(scrollIntervalId);
    }

    callReady();
  }
}

if (isBrowser) {
  if (document.addEventListener) {
    //Standards. Hooray! Assumption here that if standards based,
    //it knows about DOMContentLoaded.
    document.addEventListener("DOMContentLoaded", pageLoaded, false);
    window.addEventListener("load", pageLoaded, false);
  } else if (window.attachEvent) {
    window.attachEvent("onload", pageLoaded);

    testDiv = document.createElement('div');
    try {
      isTop = window.frameElement === null;
    } catch (e) {}

    //DOMContentLoaded approximation that uses a doScroll, as found by
    //Diego Perini: http://javascript.nwbox.com/IEContentLoaded/,
    //but modified by other contributors, including jdalton
    if (testDiv.doScroll && isTop && window.external) {
      scrollIntervalId = setInterval(function () {
        try {
          testDiv.doScroll();
          pageLoaded();
        } catch (e) {}
      }, 30);
    }
  }

  //Check if document already complete, and if so, just trigger page load
  //listeners. Latest webkit browsers also use "interactive", and
  //will fire the onDOMContentLoaded before "interactive" but not after
  //entering "interactive" or "complete". More details:
  //http://dev.w3.org/html5/spec/the-end.html#the-end
  //http://stackoverflow.com/questions/3665561/document-readystate-of-interactive-vs-ondomcontentloaded
  //Hmm, this is more complicated on further use, see "firing too early"
  //bug: https://github.com/requirejs/domReady/issues/1
  //so removing the || document.readyState === "interactive" test.
  //There is still a window.onload binding that should get fired if
  //DOMContentLoaded is missed.
  if (document.readyState === "complete") {
    pageLoaded();
  }
}

/** PUBLIC API **/

/**
 * Registers a callback for DOM ready. If DOM is already ready, the
 * callback is called immediately.
 * @param {Function} callback
 */
export default function domReady(callback) {
  if (!isBrowser) {
    console.error('runtime.domReady requires a browser environment and will be ignored.')
    return
  }
  if (isPageLoaded) {
    callback(doc);
  } else {
    readyCalls.push(callback);
  }
  return readyPromise
}