Talking about the problem of jquery clicking label twice to trigger

  • 2021-06-28 10:23:13
  • OfStack

When I encountered an label click while writing the questionnaire today, the listening click event was executed twice;Does this happen for any reason?Event Bubbling


<div class="questionBox checkBox">
      <div class="title"> 2. How do you understand the importance of innovation awareness ?</div>
      <div class="checkBoxList" data-more="2">
      <label>
       <input type="checkbox" />
       <span> Innovation consciousness is necessary for work </span></label>
      <label>
       <input type="checkbox" />
       <span> Innovation consciousness is necessary for work </span></label>
      <label>
       <input type="checkbox" />
       <span> Innovation consciousness is necessary for work </span></label>
      <label>
       <input type="checkbox" />
       <span> Innovation consciousness is necessary for work </span></label>
      <label>
       <input type="checkbox" />
       <span> Innovation consciousness is necessary for work </span></label>
       </div>
      <input type="text" class="text" placeholder=" Enter additional comments here " />
     </div>

$(".checkBoxList label").click(function(){
    var more = $(this).parent(".checkBoxList").attr("data-more");
    var length = $(this).parent(".checkBoxList").find("label").length;
    var NowCheck=0;
    for(i=0;i<length;i++){
      if ($(this).parent(".checkBoxList").find("label").eq(i).find("input").prop("checked")==true){
        pass="1"
        NowCheck = NowCheck+1
      }
    }
    if(NowCheck>more){
      alert(" Maximum number of choices for this topic " + more + " individual ")  
    }
  })

Then find the following method.

Method 1: Throw label away.

Then method 2

Recognize only input and determine that the source of the event is input (this is a solution posted by someone online)


/**
   *  Whether to include a id Of input Descendant element 
   * @param {Element} elm  Elements to Judge 
   * @param {String}  id  To match id
   * @return {Boolean}
   */
  function hasInput(elm, id) {
    for (var i = 0, inputs = elm.getElementsByTagName("input"), len = inputs.length; i < len; i++) {
      if (inputs[i].id === id) {return true;}
    }
    return false;
  }
  /**
   *  Judging under an element label Is there an association input
   * @param {Element} elm   Elements to Judge 
   * @param {Element} label label element 
   * @return {Boolean}
   */
  function isLabelhasRelativeInput(elm, label) {
    if (label.getElementsByTagName("input").length) {
      return true;
    }
    var forT = label.getAttribute("for");
    var isIE6 = !-[1,] && !window.XMLHttpRequest;// IE6 I won't support it for attribute 
    if (forT && hasInput(elm, forT) && !isIE6) {
      return true;
    }
    return false;
  }
  document.getElementById("test").onclick = function(e) {
    var ev = e || window.event;
    var srcElm = ev.target || ev.srcElement;
    if (srcElm.tagName === 'LABEL' && isLabelhasRelativeInput(this, srcElm)) {return;}
    // do something;
  }

....Anyway, I'm watching a little drunk

Then method 3.

Judging from the time stamp of event triggering, the problems related to event bubbling can be handled by this method.Safe and harmless


var evTimeStamp = 0;
  document.getElementById("test").onclick = function(e) {
    var now = +new Date();
    if (now - evTimeStamp < 100) {
      return;
    }
    evTimeStamp = now;
    console.log(2);
  }

Good to finish the discussion.I threw label away.HOHOHO


$(".checkBoxList label input").click(function(){
    var more = $(this).parents(".checkBoxList").attr("data-more");
    var length = $(this).parents(".checkBoxList").find("label").length;
    var NowCheck=0;
    for(i=0;i<length;i++){
      if ($(this).parents(".checkBoxList").find("label").eq(i).find("input").prop("checked")==true){
        pass="1"
        NowCheck = NowCheck+1
      }
    }
    if(NowCheck>more){
      alert(" Maximum number of choices for this topic " + more + " individual ")  
    }
  })

Related articles: