How to use onClick() or onSelect() on option tag in a JSP page?

How to use onClick() or onSelect() with option tag? Below is my code in which I tried to implement that, but it is not working as expected.

Note: where listCustomer domain object list getting in JSP page.

<td align="right"> 
  <select name="singleSelect" "> 
     <c:forEach var="Customer" items="${listCustomer}" >
     <option value="" onClick="javascript:onSelect(this);> <c:out value="${Customer}" /></option>
                </c:forEach>
          </select>         
        </td>   

How do I modify it to detect that an option is selected?

Answers:

Answer

Neither the onSelect() nor onClick() events are supported by the <option> tag. The former refers to selecting text (i.e. by clicking + dragging across a text field) so can only be used with the <text> and <textarea> tags. The onClick() event can be used with <select> tags - however, you probably are looking for functionality where it would be best to use the onChange() event, not onClick().

Furthermore, by the look of your <c:...> tags, you are also trying to use JSP syntax in a plain HTML document. That's just... incorrect.

In response to your comment to this answer - I can barely understand it. However, it sounds like what you want to do is get the value of the <option> tag that the user has just selected whenever they select one. In that case, you want to have something like:

<html>
 <head>
  <script type="text/javascript">

   function changeFunc() {
    var selectBox = document.getElementById("selectBox");
    var selectedValue = selectBox.options[selectBox.selectedIndex].value;
    alert(selectedValue);
   }

  </script>
 </head>
 <body>
  <select id="selectBox" onchange="changeFunc();">
   <option value="1">Option #1</option>
   <option value="2">Option #2</option>
  </select>
 </body>
</html>
Answer

Even more simplified: You can pass the value attribute directly!

<html>
 <head>
  <script type="text/javascript">

   function changeFunc($i) {
    alert($i);
   }

  </script>
 </head>
 <body>
  <select id="selectBox" onchange="changeFunc(value);">
   <option value="1">Option #1</option>
   <option value="2">Option #2</option>
  </select>
 </body>
</html>

The alert will either return 1 or 2.

Answer

The answer you gave above works but it is confusing because you have used two names twice and you have an unnecessary line of code. you are doing a process that is not necessary.

it's a good idea when debugging code to get pen and paper and draw little boxes to represent memory spaces (i.e variables being stored) and then to draw arrows to indicate when a variable goes into a little box and when it comes out, if it gets overwritten or is a copy made etc.

if you do this with the code below you will see that

var selectBox = document.getElementById("selectBox");

gets put in a box and stays there you don't do anything with it afterwards.

and

var selectBox = document.getElementById("selectBox");

is hard to debug and is confusing when you have a select id of selectBox for the options list . ---- which selectBox do you want to manipulate / query / etc is it the local var selectBox that will disappear or is it the selectBox id you have assigned to the select tag

your code works until you add to it or modify it then you can easily loose track and get all mixed up

<html>
<head>
<script type="text/javascript">

function changeFunc() {
var selectBox = document.getElementById("selectBox");
var selectedValue = selectBox.options[selectBox.selectedIndex].value;
alert(selectedValue);
}

</script>
</head>

<body>
<select id="selectBox" onchange="changeFunc();">
<option value="1">Option #1</option>
<option value="2">Option #2</option>
</select>
</body>
</html>

a leaner way that works also is:

<html>
<head>
<script type="text/javascript">

function changeFunc() {

var selectedValue = selectBox.options[selectBox.selectedIndex].value;
alert(selectedValue);
}

</script>
</head>
<body>
<select id="selectBox" onchange="changeFunc();">
<option value="1">Option #1</option>
<option value="2">Option #2</option>
</select>
</body>
</html>

and it's a good idea to use descriptive names that match the program and task you are working on am currently writing a similar program to accept and process postcodes using your code and modifying it with descriptive names the object is to make computer language as close to natural language as possible.

<script type="text/javascript">

function Mapit(){

var actualPostcode=getPostcodes.options[getPostcodes.selectedIndex].value;

alert(actualPostcode);

// alert is for debugging only next we go on to process and do something
// in this developing program it will placing markers on a map

}

</script>

<select id="getPostcodes" onchange="Mapit();">

<option>London North Inner</option>

<option>N1</option>

<option>London North Outer</option>

<option>N2</option>
<option>N3</option>
<option>N4</option>

// a lot more options follow 
// with text in options to divide into areas and nothing will happen 
// if visitor clicks on the text function Mapit() will ignore
// all clicks on the divider text inserted into option boxes

</select>
Answer
 <div class="form-group">
         <script type="text/javascript"> 
              function activa(){                                                            
                 if(v==0)
                     document.formulario.vr_negativo.disabled = true; 
                 else if(v==1)
                      document.formulario.vr_negativo.disabled = true; 
                 else if(v==2)
                      document.formulario.vr_negativo.disabled = true; 
                 else if(v==3)
                      document.formulario.vr_negativo.disabled = true; 
                 else if(v==4)
                      document.formulario.vr_negativo.disabled = true; 
                 else if(v==5)
                      document.formulario.vr_negativo.disabled = true; 
                 else if(v==6)
                      document.formulario.vr_negativo.disabled = false;}                                                   
        </script> 
        <label>&iquest;Qu&eacute; tipo de veh&iacute;culo est&aacute; buscando?</label>
        <form name="formulario" id="formulario">
          <select name="lista" id="lista" onclick="activa(this.value)"> 
              <option value="0">Vehiculo para la familia</option> 
              <option value="1">Vehiculo para el trabajo</option> 
              <option value="2">Camioneta Familiar</option> 
              <option value="3">Camioneta de Carga</option> 
              <option value="4">Vehiculo servicio Publico</option>
              <option value="5">Vehiculo servicio Privado</option>
              <option value="6">Otro</option>
          </select> 
          <br />
          <input type="text" id="form vr_negativo" class="form-control input-xlarge" name="vr_negativo"/>
        </form>
  </div>
Answer

Other option, for similar example but with anidated selects, think that you have two select, the name of the first is "ea_pub_dest" and the name of the second is "ea_pub_dest_2", ok, now take the event click of the first and display the second.

<script>

function test()
{
    value = document.getElementById("ea_pub_dest").value;
    if ( valor == "value_1" )
        document.getElementById("ea_pub_dest_nivel").style.display = "block";
}
</script>
Answer

Change onClick() from with onChange() in the . You can send the option value to a javascript function.

<select id="selector" onChange="doSomething(document.getElementById(this).options[document.getElementById(this).selectedIndex].value);"> 
<option value="option1"> Option1 </option>
<option value="option2"> Option2 </option>
<option value="optionN"> OptionN </option>
</select>
Answer

If you need to change the value of another field, you can use this:

<input type="hidden" id="mainvalue" name="mainvalue" value="0">
<select onChange="document.getElementById('mainvalue').value = this.value;">
<option value="0">option 1</option>
<option value="1">option 2</option>
</select>
Answer

in this example de select tag is named as: aula_clase_cb

<select class="form-control" id="aula_clase_cb" >
</select>

document.getElementById("aula_clase_cb").onchange = function(e){
    id = document.getElementById('aula_clase_cb').value;
    alert("id: "+id);
};
Answer

You can change selection in the function

window.onload = function () {
  var selectBox = document.getElementById("selectBox");
  selectBox.addEventListener('change', changeFunc);
  function changeFunc() {
    alert(this.value);
  }
}
<!DOCTYPE html>
<html>
  <head>
    <title>Selection</title>
  </head>
  <body>
    <select id="selectBox" onChange="changeFunc();">
      <option> select</option>
      <option value="1">Option #1</option>
      <option value="2">Option #2</option>
   </select>
  </body>
</html>

Answer

example dom onchange usage:

<select name="app_id" onchange="onAppSelection(this);">
    <option name="1" value="1">space.ecoins.beta.v3</option>
    <option name="2" value="2">fun.rotator.beta.v1</option>
    <option name="3" value="3">fun.impactor.beta.v1</option>
    <option name="4" value="4">fun.colorotator.beta.v1</option>
    <option name="5" value="5">fun.rotator.v1</option>
    <option name="6" value="6">fun.impactor.v1</option>
    <option name="7" value="7">fun.colorotator.v1</option>
    <option name="8" value="8">fun.deluxetor.v1</option>
    <option name="9" value="9">fun.winterotator.v1</option>
    <option name="10" value="10">fun.eastertor.v1</option>
    <option name="11" value="11">info.locatizator.v3</option>
    <option name="12" value="12">market.apks.ecoins.v2</option>
    <option name="13" value="13">fun.ecoins.v1b</option>
    <option name="14" value="14">place.sin.v2b</option>
    <option name="15" value="15">cool.poczta.v1b</option>
    <option name="16" value="16" id="app_id" selected="">systems.ecoins.launch.v1b</option>
    <option name="17" value="17">fun.eastertor.v2</option>
    <option name="18" value="18">space.ecoins.v4b</option>
    <option name="19" value="19">services.devcode.v1b</option>
    <option name="20" value="20">space.bonoloto.v1b</option>
    <option name="21" value="21">software.devcode.vpnfree.uk.v1</option>
    <option name="22" value="22">software.devcode.smsfree.v1b</option>
    <option name="23" value="23">services.devcode.smsfree.v1b</option>
    <option name="24" value="24">services.devcode.smsfree.v1</option>
    <option name="25" value="25">software.devcode.smsfree.v1</option>
    <option name="26" value="26">software.devcode.vpnfree.v1b</option>
    <option name="27" value="27">software.devcode.vpnfree.v1</option>
    <option name="28" value="28">software.devcode.locatizator.v1</option>
    <option name="29" value="29">software.devcode.netinfo.v1b</option>
    <option name="-1" value="-1">none</option>
</select>


<script type="text/javascript">

    function onAppSelection(selectBox) {
        // clear selection
        for(var i=0;i<=selectBox.length;i++) {
          var selectedNode  = selectBox.options[i];
             if(selectedNode!=null) {
                  selectedNode.removeAttribute("id");
                  selectedNode.removeAttribute("selected");
            }
        } 
        // assign  id and selected
        var selectedNode = selectBox.options[selectBox.selectedIndex];
        if(selectedNode!=null) {
            selectedNode.setAttribute("id","app_id");
            selectedNode.setAttribute("selected","");
        }
     }

</script>
Answer

In my case:

<html>
 <head>
  <script type="text/javascript">

    function changeFunction(val) {

       //Show option value
       console.log(val.value);
    }

  </script>
 </head>
 <body>
   <select id="selectBox" onchange="changeFunction(this)">
     <option value="1">Option #1</option>
     <option value="2">Option #2</option>
   </select>
 </body>
</html>
Answer
<html>
<head>
<title>Cars</title>
</head>
<body >

<h1>Cars</h1>
    <p>Name </p>
        <select id="selectBox" onchange="myFunction(value);">
            <option value="volvo" >Volvo</option>
            <option value="saab"  >Saab</option>
            <option value="mercedes">Mercedes</option>
        </select>        
<p id="result"> Price : </p>
<script>
function myFunction($value)
{       
    if($value=="volvo")
    {document.getElementById("result").innerHTML = "30L";}
    else if($value=="saab")
    {document.getElementById("result").innerHTML = "40L";}
     else if($value=="mercedes")
    {document.getElementById("result").innerHTML = "50L";}
}
</script>
</body>
</html>```

Tags

Recent Questions

Top Questions

Home Tags Terms of Service Privacy Policy DMCA Contact Us Javascript

©2020 All rights reserved.