Using DataView as a dynamic search result table in Wicket 1.4 - ajax

Question

I'm fairly new to Wicket but I've already run into a very strange problem.
I'm creating a page with a pretty basic search form and a results table (a DataView) which is initially empty. When the user enters data into the fields and clicks "Search", the app calls some backend services which are then used to populate the DataView.
However the user has to click "Search" twice for the data to be displayed.
I finally tracked this down, and it's because Wicket is using zero for the number of items to be displayed for the first "Search" click. At the second click, the rows have already been added and Wicket has already calculated the proper number of rows to display, so it decides it will show the data.
In AbstractPageableView.getItemModels(), the size of the results to display is initially zero, because I don't load the table with any initial data probably.
I got around this problem by loading the DataView with empty rows on page load. This seems to trick the DataView into using the displaying the data for the first "Search" click.
My question is: am I doing this right? Is there another repeater that is better for this task? Is this a bug or something?

Answer 1

Finally cracked it: it was because I was loading the data in my data provider only in the iterator() method, and the data provider's size() method is usually called before the iterator() method is. I should have been loading the data in its own method and calling that method from iterator() and size(). Doing that fixed it.
Data Provider before (Splc is the DTO):
SearchResultsDataProvider implements IDataProvider<Splc> {
/**
* The list of search results
*/
private List<Splc> models;
#Override
public void detach() {
// Do nothing
}
#Override
public Iterator<Splc> iterator(int first, int count) {
// load the data into the list of models
models = service.getSplcModels();
return models.subList(....).iterator();
}
#Override
public IModel<Splc> model(Splc object) {
return new Model<Splc>(object);
}
#Override
public int size() {
return models.size();
}
}
Data Provider after:
SearchResultsDataProvider implements IDataProvider<Splc> {
private List<Splc> getModels() {
// load the data into the list of models
return service.getSplcModels();
}
#Override
public void detach() {
// Do nothing
}
#Override
public Iterator<Splc> iterator(int first, int count) {
return getModels().subList(....).iterator();
}
#Override
public IModel<Splc> model(Splc object) {
return new Model<Splc>(object);
}
#Override
public int size() {
return getModels().size();
}
}