On Thu, 2002-09-26 at 02:28, Eric Du wrote: > I think breaking a loop is a general and useful feature for better > performance.
sometimes...
> Here is a case:
>
> Assuming a multiple select control in a form, and a java variable
> id2textMap keeps all the items showed in the select control, each entry
> in the map is responding to an item in the control and "id" is the value
> and "text" is the text. A variable selIDs keeps all selected items. Now
> the jstl codes to generate the select control is as follows:
>
> <select name="selIDs" size="5" multiple>
> <c:foreach var="entry" items="id2textMap">
> <option value="<c:out value="${entry.key}"/>"
> <c:foreach var="selID" items="selIDs">
> <c:if test={selID==entry.key}>
> selected
> <%-- I WANT TO BREAK THE LOOP HERE -->
> </c:if>
> </c:foreach>
> >
> <c:out value="${entry.value}"/>
> </option>
> </c:foreach>
> </select>
>
>
> In our project, we have a page that contains more than 50 select
> controls like that and the performance to display that page with JSTL is
> not good.
in this case, i think the best solution would be to make the selIDs also
a Map. then your code gets a) simplier, b) much quicker regardless of
the size of the lists or the selected items. you would have:
<c:foreach var="entry" items="id2textMap">
<option value="<c:out value="${entry.key}"/>"
<c:if test="${not empty selIDs[entry.key]>selected</c:if>>
<c:out value="${entry.value}"/></option>
</c:forEach>
i might have typed something in not quite right, but it should work
pretty close to this.
i don't necessarily stay way from breaking loops as a religion, but i do
find that 9 times out of 10 there is a better way.
> Shawn Bayern wrote:
> >>Would it be possible to have an loop tag which iterates based on a
> >>boolean condition?
>
> > A <c:while>? Yes, additions like this are always possible in future
> > versions if there's enough perceived need.
> >
> > I'd suggest mailing [EMAIL PROTECTED] with the suggestion. Be sure
> > to indicate the situations where this would be useful to you, with as
> > specific examples as possible.
> >
> > Best,
> >
>
>
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--
CraigL->Thx();
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