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javascript implements case analysis of permission selection based on DOM

  • 2020-06-12 08:31:31
  • OfStack

This article illustrates javascript's method of implementing permission selection based on DOM. Share to everybody for everybody reference. Specific implementation methods are as follows: 


<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title> Permissions to choose </title>
<script type="text/javascript">
//==================== Multiple operations ====================================
function selMultiple(selectSrc, selectDes) {
  for (var i = selectSrc.childNodes.length - 1; i >= 0; i--) {
    var option = selectSrc.childNodes[i];
    if (option.selected == true) {
      selectSrc.removeChild(option);
      option.selected = false;
      selectDes.appendChild(option);
    }
  }
}
function selectToRight() {
  var selectSrc = document.getElementById("select1");
  var selectDes = document.getElementById("select2");
  selMultiple(selectSrc, selectDes);
}
function selectToLeft() {
  var selectSrc = document.getElementById("select2");
  var selectDes = document.getElementById("select1");
  selMultiple(selectSrc, selectDes);
}
//==================== selection ====================================
function selAll(selectSrc, selectDes) {
//       There's something wrong with that , found selectSrc.childNodes.length Actually is equal to the 10, In fact only 5 An element 
//      for (var i = 0; i < selectSrc.childNodes.length; i++) {
//        var option = selectSrc.childNodes[0];
//        selectSrc.removeChild(option);
//        selectDes.appendChild(option);
//      }
  var options = selectSrc.getElementsByTagName("option");
  var optLength = options.length;
  /*
   Pay attention to :for Cannot be used directly in a loop options.length, because selectDes.appendChild After performing 
   Can lead to options.length Reduction of 1, So the first options.length Deposit to 1 I'm going to set it aside 
  */
  for (var i = 0; i < optLength; i++) {
    var option = options[0]; // This is always the number one 0 An element 
    selectDes.appendChild(option);
  }
  selectSrc.options.length = 0;
}
function selectToRightAll() {
  var selectSrc = document.getElementById("select1");
  var selectDes = document.getElementById("select2");
  selAll(selectSrc, selectDes);      
}
function selectToLeftAll() {
  var selectSrc = document.getElementById("select2");
  var selectDes = document.getElementById("select1");
  selAll(selectSrc, selectDes);    
}
</script>
</head>
<body>
<select id="select1" multiple="multiple" style="float:left;width:100px;height:200px;">
<option> add </option>
<option> delete </option>
<option> Modify the </option>
<option> save </option>
<option> The query </option>
</select>
<div style="float:left;width:50px;">
<input type="button" style="float:left;width:100%;" value=">" onclick="selectToRight()" />
<input type="button" style="float:left;width:100%;" value="<" onclick="selectToLeft()" />
<input type="button" style="float:left;width:100%;" value=">>" onclick="selectToRightAll()" />
<input type="button" style="float:left;width:100%;" value="<<" onclick="selectToLeftAll()" />
</div>
<select id="select2" multiple="multiple" style="float:left;width:100px;height:200px"></select>
</body>
</html>

Hopefully, this article has been helpful in your javascript programming.

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