如何获取由dom创建的单选按钮的实际标签值/文本?

时间:2014-03-25 23:55:30

标签: javascript jquery html dom

基本上我试图使用dom创建的getElementById来获取带有实际标签的警报框(选择编辑或删除),但如果我在alert(a)之后取消注释代码并删除alert(a)它甚至没有为我创建按钮..任何想法如何做或我做错了什么?

<HTML>  
<HEAD>  
<TITLE> New Document </TITLE>  
<SCRIPT LANGUAGE="JavaScript">
function createRadio(){  
var objDiv = document.getElementById("radioDiv");  

    var radioItem1 = document.createElement("input");  
    radioItem1.type = "radio";  
    radioItem1.name = "radioGrp";  
    radioItem1.id = "rad1";  
    radioItem1.value = "myradio1";  

//        radioItem1.defaultChecked = true;   
//        radioItem1.checked = true;  

    var radioItem2 = document.createElement("input");  
    radioItem2.type = "radio";  
    radioItem2.name = "radioGrp";  
    radioItem2.id = "rad2";  
    radioItem2.value = "myradio2";  
//        var pA= prompt("Type name for 1");
//        var pB= prompt("Type name for 2");
    var objTextNode1 = document.createTextNode("Edit");  
    var objTextNode2 = document.createTextNode("Delete");  

    var objLabel = document.createElement("label");  
    objLabel.htmlFor = radioItem1.id;  
    objLabel.appendChild(radioItem1);  
    objLabel.appendChild(objTextNode1);  

    var objLabel2 = document.createElement("label");  
    objLabel2.htmlFor = radioItem2.id;  
    objLabel2.appendChild(radioItem2);  
    objLabel2.appendChild(objTextNode2);  


    objDiv.appendChild(objLabel);  
    objDiv.appendChild(objLabel2);  

}   

function test()
{
//    var a = document.getElementById("radioDiv").firstChild;


var a = document.getElementById("radioDiv").firstChild;
alert(a);
//    if (a=="Edit")
//    {
//        alert("Edit");
//    }
//    else if (a=="Delete")
//    {
//        alert("Delete");
//    }
//    else()
//    {
//        alert("Try Again");
//    }
}

</SCRIPT>  
</HEAD>  

<BODY>  

<BUTTON onclick="createRadio()">Create Radio Buttons</BUTTON>
<BUTTON onclick="test()">Alert</BUTTON>
<div id="radioDiv"></div>  
</BODY>  
</HTML>  

1 个答案:

答案 0 :(得分:3)

(编辑)好的,看看这个!并尝试用这种技术编写未来的问题:通用,短函数和注释。祝好运!

<html>
    <head>
        <script>
        /**
           * Create a group of radiobuttons
           * @param whereToAttach Div to attach generated things
           * @param groupname Name for the group
           * @param options Array of options ["one","two",...
           */

          function createRadioGroup(whereToAttach, groupname, options) {

              var objDiv = document.getElementById(whereToAttach);
              objDiv.innerHTML=""; // we clear it just in case
              for (var i = 0, len = options.length; i < len; i++) {
                  objDiv.appendChild(createRadioButtonWithLabel(name, options[i], options[i]));
              }
          }

          /**
           * Get a group's selected node
           * @param groupname Name of the group
           * @return The radiobutton element that is checked, or null if none
           */

          function getSelectedNode(groupname) {
              var nodes = document.getElementById("radioDiv").childNodes;
              for (var i = 0; i < nodes.length; i++) {
                  // nodes[i] is each label child of radioDiv
                  // we want its button to check if pressed
                  var radiobutton=nodes[i].firstChild;
                  if (radiobutton.checked) return radiobutton;
              }
              return null; // none selected
          }


          /**
           * Creates a label with a radiobutton and a text node
           * @param name Name of the group this radiobutton belongs to
           * @param label Label for the radiobutton
           * @param value Value for the radiobutton
           */

          function createRadioButtonWithLabel(groupname, label, value) {

              var objTextNode = document.createTextNode(label),
                  objLabel = document.createElement("label"),
                  objRadioButton = createRadioButton(groupname, value);

              objLabel.appendChild(objRadioButton);
              objLabel.appendChild(objTextNode);

              return objLabel;
          }

          /**
           * Creates a radio button
           * @param groupname Name of the group this radiobutton belongs to
           * @param value Value for the radiobutton
           */

          function createRadioButton(groupname, value) {
              var radioItem = document.createElement("input");
              radioItem.type = "radio";
              radioItem.name = groupname;
              radioItem.value = value;
              return radioItem;
          }

          //////////////////////////////////////////////////////////////////////

          function createStuff() {
              createRadioGroup("radioDiv", "coolMenu", ["Edit", "Delete", "Modify", "Modify a lot", "Have a beer", "Walk the dog", "f** my girlfriend"]);
          }

          function testStuff() {
              var nodeSelected = getSelectedNode("coolMenu");
              alert(nodeSelected.value);
          }

        </SCRIPT>  
    </HEAD>  
    <BODY>  
        <BUTTON onclick="createStuff()">Create Radio Buttons</BUTTON>
        <BUTTON onclick="testStuff()">Alert</BUTTON>
        <div id="radioDiv"></div>
    </BODY>  
</HTML>

------ OLDER MSG

你有一个愚蠢的错字和一个小问题。这有效:

        function test()
        {
            var b = document.getElementById("radioDiv").firstChild;

            // b is the LABEL OBJECT, its text is b.innerText

            var a=b.innerText
            alert(a);


            if (a=="Edit")
            {
                alert("Edit");
            }
            else if (a=="Delete")
            {
                alert("Delete");
            }
// THIS IS THE TYPO >>>   else()
            else 
            {
                alert("Try Again");
            }
        }

但是,此代码不会为您提供所选标签,而是第一个标签(您要求firstChild

如果你想找出使用​​你动态构造的结构选择哪个无线电(顺便说一下这很复杂),你可以定义这个方便的功能:

function isRadioButtonPressed(number) {
   return document.getElementById("rad"+number).checked;
}

因为您已命名为radiobuttons rad1rad2,...

所以你可以这样做:

var isEditSelected=isRadioButtonPressed(1); // will return true if edit is selected
var isDeleteSelected=isRadioButtonPressed(2);  // will return true if delete is selected

一些建议:

  • 您应该创建像isRadioButtonPressed这样的实用程序函数,以避免使用firstchild,document.getElementById等反复写入长表达式...如您所见,代码编写简单的东西会非常复杂。

  • 您应该使用 FireBug Chrome / Safari开发人员工具。如果您使用 chrome ,请转到“工具”菜单并选择“开发人员工具”。将出现一个窗口,您将看到代码中的错误。如果您使用原始问题执行此操作,则会看到Chrome如何抱怨else()行上的语法错误。如果您使用 FireFox ,请下载 Firebug 插件,也是如此。这是开发网页的必要条件。

更多示例功能:

 function createRadioButton(id, name, value) {
      var radioItem = document.createElement("input");  
      radioItem.type = "radio";  
      radioItem.name = name;
      radioItem.id = id;  
      radioItem.value = value; 
      return radioItem;
 }

看看你的createRadio现在有多酷:

 function createRadio() {

      var radioItem1=createRadioButton("rad1","radioGrp", "myradio1"),
          radioItem2=createRadioButton("rad2","radioGrp", "myradio2");

       .
       .
 }

阅读不是更容易吗?

希望有所帮助:)