Pass additional parameters to the LazyDataModel load method on pagination

Question

I want to pass additional parameters when a paginator button is clicked. The data looks like this:

<p:dataGrid 
    var="citem" 
      value="#{group.lazyItemGroup}"
      paginator="true" 
      rows="4"
      lazy="true"
        columns="2"
        layout="grid"
        id="items"
        paginatorTemplate="{CurrentPageReport}  {FirstPageLink} {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink} {RowsPerPageDropdown}"
        rowsPerPageTemplate="6,12,16"
>
    ...
    ...
    ...
</p:dataGrid>

Can I use something like this?

<p:inputText id="id" value="#{group.id}" type="hidden" />
or
<f:attribute name="id" value="#{group.id}" />

Answer 1

If you are referring to the load method of the LazyDataModel you have implemented, then no, you cannot simply add parameters to that method.

Since you were talking about "when a paginator button is clicked", I assumed you had a page event listener in place. Apparently you haven't, so add that to your p:dataGrid:

<p:dataGrid ...>
  <p:ajax event="page"
          listener="#{yourBean.yourListener}"/>
</p:dataGrid>

And to your bean:

public void yourListener(PageEvent event) {
  ...
}

In your listener you can pass anything to your custom lazy data model instance, and pick that up in the load method. You could also add a <f:attribute .../> to your data grid component, which can be read in the listener method (see Send additional parameter to Ajax event listener).

Please note that you can get the page from the page event:

event.getPage();

This might help in determining what additional data to set.