3 examples of 'document getelementbyclass' in JavaScript

292
getElementsByClassName(className) {
293
  if (typeof className !== 'string') return [];
294
295
  return this.$_tree.getByClassName(className);
296
}

355
setElementClassNames(elementClassNames) {
356
  // apply to the bg
357
  var iframe = goog.dom.getElementsByTagNameAndClass(
358
      'iframe', null, this.element)[0];
359
  // get the iframe document
360
  var iframeDoc = goog.dom.getFrameContentDocument(iframe);
361
  // apply css classes of the element
362
  // apply it on  tag instead of body,
363
  // because body represents
364
  // the '.silex-element-content' element of Silex text elements
365
  // so it has these classes: 'silex-element-content normal'
366
  var htmlElement = iframeDoc.getElementsByTagName('html')[0];
367
  htmlElement.className = elementClassNames;
368
  // body represents the '.silex-element-content' element of Silex text elements
369
  // so it has these classes: 'silex-element-content normal'
370
  iframeDoc.body.className = 'silex-element-content normal';
371
  // keep the size of the text field
372
  htmlElement.style.left = '10px';
373
  htmlElement.style.right = '20px';
374
  htmlElement.style.height = '100%';
375
  htmlElement.style.overflowX = 'hidden';
376
  htmlElement.style.overflowY = 'scroll';
377
  iframeDoc.body.style.height = 'auto';
378
  iframeDoc.body.style.position = 'initial';
379
  // keep the pointer events which are disabled on element content (see front-end.css)
380
  iframeDoc.body.style.pointerEvents = 'auto';
381
}

580
Video.prototype.getElementByClass = function getElementByClass(className) {
581
  return this.element.getElementsByClassName(className)[0];
582
};