Question

接着我的上一个问题。我做了一个辅助函数（见下文），将元素插入DOM。函数的一部分使用'instanceof'来确定'this'元素是否为HTMLMediaElement的实例，并通过参数'elemSrc'确定源属性。

我的问题：是否可以检查元素是否“正在”定义要定义的源属性？我问的原因是，然后我可以对所有“期望”定义了源属性的元素使用此函数。我知道我可以使用instanceof并取消使用source属性的每个元素，但如果可能的话，我希望使用更流畅的方式。

'e'

Answer 1

您可以检查<div class="modal fade" id="addEvento" tableindex="-1" role="dialog" aria-labelledby="exampleModalLabel"> <?php echo $etc; ?>是否作为HTML元素中的键存在。

v-model

演示：

src

Answer 2

这是更新的功能：

function insertElem(numberOfElems, elemTag, elemId, elemClass, parentSelector, elemSrc){
/*
* numberOfElements:-    Pass in a whole integer.
* elemTag:-             Pass in the element tag type (as a string).              
* elemId:-              Pass in a name for the element id (as a string),
                        an integer is appended to the id name by the for 
                        loop.
* elemClass:-           Pass in a name for element class (as a string).
* parentSelector:-      Pass in the identifier of the parent element 
                        (as a string).
                        * querySelector prefixes:    # = id
                                                     . = class
                                                     none = tag 
*elemSrc:-              Pass in the source media url (as a string). 
*/      
  if (numberOfElems > 1) {
    for (i = 0; i < numberOfElems; i++) {
      var elem = this[elemId + i];
      elem = document.createElement(elemTag);
      elem.id = elemId + '_' + i;
         if (elemClass) {
            elem.className = elemClass;
         }
      parentEl = document.querySelector(parentSelector);
      parentEl.appendChild(elem);
        if('src' in elem) {
            elem.src = elemSrc;
        }
    }
  } else {
    var elem = this[elemId];
    elem = document.createElement(elemTag);
    elem.id = elemId;
        if (elemClass) {
            elem.className = elemClass;
        }
    parentEl = document.querySelector(parentSelector);
    parentEl.appendChild(elem);
       if('src' in elem) {
            elem.src = elemSrc;
      }
  }
}

检查HTML元素是否需要source属性

2 个答案: