Hello everyone,
this my first post to the list, so I would like to give many thanks to the
authors and all contributors to the great Apache Wicket project. We silently
develop a medium sized application for over two years (at the Warsaw University
of Technology), and usually we have resolved all issues by searching answers on
this users group or by googling them. This time I would ask you for
consultation.
My goal is to provide a download link for CSV data which will be generated
dynamically and during the time consuming generation I would like to show a
user an indicator. Like the one the IndicatingAjaxLink class do.
My questions are:
1) Is the following source code created the 'wicket way' or I am breaking
somewhere else opened door?
The 'trick' I have employed, that I am not sure of, is the redirection to the
AbstractDefaultAjaxBehaviour in the onClick method of the IndicatingAjaxLink.
2) The problem with this code is that, when I click the download link the
second time the indicator is not revolving. It is being displayed correctly,
and hidden on time, and the CSV data is exported correctly. The problem is that
the indicator is not moving.
Thank you for you assitance in advance,
Robert Szmurlo
Java:
public class HomePage extends WebPage {
private AbstractDefaultAjaxBehavior b;
private String data = null;
public HomePage(final PageParameters parameters) {
final ByteArrayResource bar = new ByteArrayResource("text/csv") {
@Override
public byte[] getData(Attributes attributes) {
byte[] bytes = null;
try {
bytes = data.getBytes();
} catch (Exception e) {
e.printStackTrace();
}
return bytes;
}
@Override
protected void configureResponse(ResourceResponse
response,Attributes attributes) {
super.configureResponse(response, attributes);
response.setFileName("report.csv");
}
};
add( b = new AbstractDefaultAjaxBehavior() {
@Override
protected void respond(AjaxRequestTarget target) {
getRequestCycle().scheduleRequestHandlerAfterCurrent(new
ResourceRequestHandler(bar, getPageParameters()));
}
});
add( new IndicatingAjaxLink<Void>("link") {
@Override
public void onClick(AjaxRequestTarget target) {
prepareData(); // takes some time
if (target != null) {
*target.appendJavaScript("window.location='" + b.getCallbackUrl() + "'");*
}
}
});
}
protected void prepareData() {
////////// JUST FOR TEST
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
/////////////////////////
// atach data?
data = "No.;Name\n" +
"1.;John\n" +
"2.;Mary";
}
}
HTML:
<html>
<body>
<a wicket:id="link">Export CSV</a>
</body>
</html>
