从JSP页面调用Java Script函数不返回值

Question

I have written a java script function which will return Language name based on code passed to the function as argument.

I am getting code from the servlet as response. I tried in the following way:

----
</fieldset>
    <fieldset class = "field">
        <legend>Language</legend>
        <table border = '0'>
            <tr>
                <td>Spoken:</td>
                <!-- <td><input type = "text" name = "FirstName"  value = "${spoken}"/></td> -->
                <td><input type = "text" name = "spoken"  value = getLanguage(${spoken}) /></td>
            </tr>
            <tr>
                <td>Written:</td>
                <td><input type = "text" name = "written"  value = "${written}"/></td>
            </tr>
        </table>

</fieldset>
----

Java script function:

<script>
function getLanguage(code) {
    if(code.equals("EN"))
        return "ENGLISH";
    else if(code.equals("SP"))
        return "SPANISH";
    else
        return "";
}
</script>    

But in output instead of displaying language I am getting function call displayed. Can someone tell me what is happening wrong here?

Answer 1

Maybe you can't do like this. You will be passing code to js function and then inside a js function you can dom manipulation. Like that;

<script>
function setLanguage(code, elementId) {
    if(code.equals("EN"))
        document.getElementsByTagId(elementId).val = "ENGLISH";
    else if(code.equals("SP"))
        document.getElementsByTagId(elementId).val = "SPANISH";
    else
        document.getElementsByTagId(elementId).val = "Unknow";
}
</script>    

Answer 2

You need to place calls to javascript function between <script> and </script> .

There could be several ways of solving this. One solution is as follows:

In your html, use

<input type = "text" name = "FirstName"  data-value = "${spoken}"/>

Note how data-value attribute holds the value of spoken .

Then have the following <script> block after getLanguage() is defined:

<script>

(function() {
  var input = document.querySelector('input[name=FirstName]')[0];
  var code = input.getAttribute('data-value');
  input.setAttribute('value', getLanguage(code));

})();

</script>