Question

I have a JSF page that accepts a viewparam and sets a variable which looks up the respective entity from the database and load the bean with the found details as follows:

<f:metadata>
    <f:viewParam name="attractionId" value="#{attractionsBean.attractionId}" />
</f:metadata>

I have a google map using the primefaces API and when a marker is dragged, an ajax call is issued to update the marker location.

<h:outputText value="Location" />
<f:view contentType="text/html">
    <p:gmap id="gmap" center="41.381542, 2.122893" zoom="10" type="HYBRID" style="width:380px;height:350px"
                        model="#{attractionsBean.attractionModel.mapModel}"
                        markerDragListener="#{attractionsBean.onMarkerDrag}"
                        onMarkerDragUpdate="growl" />
                </f:view>

The problem is that after every marker drag event and ajax call, the method setAttractionId from the metadata is called every time.

What can be a solution for this problem to prevent calling the setAttractionId method everytime?

Answer 1

The solution for this problem is as follows after a lot of hours trying to find a workaround:

1. Make the ManagedBean as @ViewScoped in order to be the same bean while still on the same page

2. Instead of retrieving the entity from the database in the setter of the attractionId, I introduced a @PostConstruct method in the view scoped bean to retrieve the object by the view parameter using the code as follows:

   @PostConstruct
   public void setupAttractionModel() {
       this.attractionId = FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap().get(ATTRACTION_ID_VIEW_PARAM);
       // Lookup by attractionId ...
   }
   

   The postconstruct method is called before every page that requires the bean.

3. Remove the <f:metadata> tag which is causing the trouble