How to use rich:dataTable with row selection without binding - jsf

Question

I'm currently migrating a legacy project from JSF 1 (with RichFaces 3) to JSF 2 (with RichFaces 4). The project has several rich:dataTables with checkboxes next to the items. At the bottom of the page, there are a few action buttons to so something with all selected items (add to favorites, export as PDF, ...).
The checkboxes are the reason why the rich:dataTables have a binding to the corresponding UI beans. But most of the UI beans are session-scoped. In between, I've learned that binding in combination with session-scope is not a good idea. And indeed, I'm having lots of "duplicate ID" errors that go away if I change the scope to "request". But it's not that easy. These beens have some state that needs to be preserved between requests and an elaborated state initialization and cleanup logic.
I think I have two options:
change the beans to request-scope, do some massive refactoring by extracting the state into some new "stateObjects" to be saved in a new "sessionBean", and completely rewrite the state logic
remove the bindings, but how can I determine which entries of the rich:dataTable have their checkboxes selected?
Curiosly, the session-scope and bindings worked together very well with JSF 1. And the decision for making the beans session-scoped was made a long time before I took over the project.

Answer 1

You can remove binding and change actions (bean scope changing not needed).
1) Simple case: data table with list of items and after row selection detail for selected item is displayed
Following example uses Javascript (storing item ID in bean and calling action for presenting data related to this ID):
<a4j:jsFunction name="selectRow" action="#{locationAction.showSelectedLocation}">
<a4j:param name="locationId" assignTo="#{locationAction.selectedLocationId}" />
</a4j:jsFunction>
<rich:dataTable id="locationTable"
value="#{locationAction.locationList}" var="location"
rows="#{referenceData.recordsPerPage}"
onrowclick="selectRow('#{location.locationId}')">
...
</rich:dataTable>
2) Case with multiple check boxes and action button:
<rich:dataTable id="productTable" var="res"
value="#{productPicker.pickerList}">
...
<rich:column>
<h:selectBooleanCheckbox id="selectChck" value="#{res.selected}" />
</rich:column>
...
</rich:dataTable>
<a4j:commandButton value="#{msg.detachSelected}"
action="#{productPicker.deleteSelectedFromPickerList}"
render="picker" />
where item list is private List<PickerItem> pickerList; and item is from
public class PickerItem {
private Long id; // with getter and setter
// private Record item; // with getter and setter
private boolean selected; // with getter and setter
}
In my code there are equals and hashCode methods as pat of PickerItem class, but it should works without it too.