Primefaces timeline onchanged executes but does not call method on bean

Question

I am attempting to add primefaces to an existing Spring/JSF (myfaces) project. I have the actual timeline component working (or at least loading with the correct data), but the event listeners don't seem to work correctly. I have tried a number of configurations but can't seem to resolve this issue.

<p:timeline id="timeline1" 
        value="#{timelineView.getModel(searchFacade.dataModel)}" 
        editable="true" eventMargin="10" eventMarginAxis="0" 
        start="#{timelineView.start}" 
        end="#{timelineView.end}" 
        showNavigation="true" showButtonNew="true" 
        axisOnTop="true" stackEvents="false"
        oncomplete="styleEvents();">  

    <p:ajax event="changed" listener="#{timelineView.onEdit()}" oncomplete="restyleTimeline()" />  
</p:timeline>

In the above code the changed event is triggered and there is an AJAX call made. In the network pane of the browser I can see that the AJAX call is always to the URL of the current page (so like /mypage.jsf?conversationCode=a - I'm also using Apache Orchestra obviously)

The actual form data being sent for the changed event looks like this:

javax.faces.partial.ajax:true
javax.faces.source:timeline1
javax.faces.partial.execute:timeline1
javax.faces.behavior.event:changed
javax.faces.partial.event:changed
timeline1_eventIdx:0
timeline1_startDate:1498881600000
timeline1_endDate:1510894800000
timeline1_group:<div class='timeline-group'><div class='timeline-row timeline-row-group'>Group One/div><div class='timeline-row timeline-row-sub'>Group One subtitle</div><div class='timeline-row timeline-row-details'>Group One details</div></div>
mainForm:j_id_mt_SUBMIT:1
javax.faces.ViewState: Big hash as usual

The bizarrely long group name is because I am formatting the output group names into a more detailed title for the row btw.

The bean in the back (imports and package omitted):

public class TimelineView<T> implements Serializable {
    private static final long serialVersionUID = 1L;

    TimelineView<T> timelineView;

    public TimelineModel getModel() {
        return timelineView.getModel();
    }
    public TimelineModel getModel(ListDataModel<? extends Row<T>> results) {  
        return timelineView.getModel(results);
    }
    public void setTimelineView(TimelineView<T> timelineView) {
        this.timelineView = timelineView;
    }
    public Date getStart() {  
        return timelineView.getStart();  
    }
    public Date getEnd() {  
        return timelineView.getEnd();  
    }
    public void onEdit(TimelineModificationEvent e) {
        timelineView.onEdit(e);
    }
    public void onSelect(TimelineSelectEvent e) {
        timelineView.onSelect(e);
    }
}

The functionality and code inside these methods doesn't matter because when I set a breakpoint I can see that the onEdit method is never called and neither was the onSelect method when I had a select event in the timeline.

Since I have Spring handling all beans, my configuration was just this, located in the ApplicationContext.xml file:

<bean id="timelineView" class="com.mycompany.projectone.view.timeline.TimelineView" />

I have tried adding a form around the timeline, which made no difference, and have also tried adding process=":form_id", which caused the error "Cannot find component for expression ":form_id"".

As an alternative that would also suit my needs, does anyone know how to send primefaces events to a javascript function to be handled? For example, if the user moves the start and end points of the item in the timeline I would like to update the displayed start and end dates.

I would also like to change or intercept the delete behavior and modify what occurs when the delete link is clicked.

Any help would be hugely appreciated. Thanks.

EDIT

---

The suggested potential duplicate does not address the symptoms nor the actual solution - see answer below.

Answer 1

Okay, so the answer turns out to be that the Primfaces timeline component must have a widgetVar set in order for the p:ajax and pe:javascript calls to work. Incredibly simple solution but so infuriatingly difficult to find.