Question

I have a drop down menu which fills with some doc names. Now when a person selects a document it calls onDocumentChange() method.

To fill the drop down menu i receive a object called result which is a list of doc objects from server.

<select id="documentSelect" onChange="onDocumentChange()">
<c:forEach items="${results}" var="result">
    <option id="${result.getDocDisplayURL()}"><c:out value="${result.getDocFn()}"/></option>
</c:forEach>
</select>

Till this point it is strainght forward.

Now this doc object has some other attributes called date and time. Now when the user clicks any item from drop down menu i want to send that particular items time and date attributes to onDocumentChange() method. How can i do that.

I am guessing something like this

<select id="documentSelect" onChange="**onDocumentChange(result.date, result.time)**">
<c:forEach items="${results}" var="result">
<option id="${result.getDoc()}"><c:out value="${result.getText()}"/></option>
</c:forEach>
</select>

Thanks

Answer 1

You seem to be thinking that JavaScript runs together with Java/JSP. This is untrue. Java/JSP produces HTML and JavaScript is part of that HTML and works on the HTML DOM tree only. You need to make sure that your Java/JSP code produces HTML code containing exactly the information JavaScript needs to access. You can let Java/JSP print those variables as an attribute of a HTML element, like <option> in your case. You can use custom data-* attributes in HTML to append custom attributes.

<option value="${result.doc}" data-date="${result.date}" data-time="${result.time}">

You can get the currently selected <option> element in JavaScript as follows

var option = select.options[select.selectedIndex];
var doc = option.value;
var date = option.getAttribute("data-date");
var time = option.getAttribute("data-time");
// ...

You only need to change the onchange handler to pass the HTML <select> element itself

onchange="onDocumentChange(this)"

with

function onDocumentChange(select) {
    // ...
}

By the way, why are you using separate properties for date and time instead of a single java.util.Date property? There’s something wrong in the model design.