How do I execute code when the user clicks a cell in a data table? Similarly to listener and actionListener on a p:commandButton.
For example
<p:commandButton oncomplete="PF('editProductDialog').show()"
actionListener="#{bean.doStuffToGetASelectOneMenuReadyforTheEditProductDialog()}" />
public void doStuffToGetDialogReady() {
//query databases to get select item list
}
The database is only queried when/if the user clicks the commandButton
But for p:dataTable inline cell editing how to I call code that would query database to get select items only when they click the data table cell to make an edit?
<p:cellEditor>
<f:facet name="output"/>
<f:facet name="input">
<p:selectOneMenu>
<f:selectItems value="#{bean.someListSpecificToThisUser}" />
</p:selectOneMenu>
</f:facet>
</p:cellEditor>
I've been populating the someListSpecificToThisUser selectItems list in the @PostConstruct init() method
@PostConstruct
public void init() {
//code specific to the page and datatable
someListSpecificToThisUser = service.queryValuesForUser(user);
}
but if the user never clicks the cell to edit the selectOneMenu value then I hit the database and stored the list in memory for no reason. Or should I not worry about the overhead?
In case of cell editing of a
p:dataTablethere are a few events you can use:All taking a
org.primefaces.event.CellEditEventas the listener parameter.You could use the
cellEditInitmethod to populate the list when it is stillnull. Downside is that this requires an Ajax call on each edit init.An other option you have is to store the list in a
SessionScopeduser bean, which will cost you some memory.The option to pick depends on the size of the list, how much time it takes to fetch the list and how many edits you expect. If you don't expect much edits, use an Ajax listener to populate the list. If the list is long and takes some time to load, I would switch to a
p:autoCompletefield.See also: