I am trying to come up with a solution to large datasets by only loading 25
records at a time. I have looked at
<http://wiki.apache.org/myfaces/WorkingWithLargeTables>
http://wiki.apache.org/myfaces/WorkingWithLargeTables but am having a
problem with the DataScroller component displaying the correct page when I
try to position to a particular page within the result.
So here's the scenario. Admin logs in. Admin displays list of users 1
through 25. Admin hits page 2 in data scroller. Admin choses to edit a user
on the second page which takes them to the edit page. Admin selects 'SAVE'
button and is returned to the user list page. The data in the result is
correct in that it is showing the second page, but the datascroller states
it is on the first page (i.e. number 1 is bold between the forward/backward
arrows and it is displaying 1 of 10 vs. 2 of 10 as it should be displaying).
I have the following method named getUserListDataModel that provides the 25
records at a time. I believe what is happening is that when I leave the
user list page and come back the datascroller component is re-initializing
itself. Is there a way to tell it that it is on the 2nd page vs. the first
page?
My version of MyFaces is 1.0.7
public class UcerController{
private int userListCurPage = 1;
private int userListCurStart = 1;
...
public DataModel getUserListDataModel() {
HtmlDataTable data2 = (HtmlDataTable)
UIHelper.findComponent("form1:data2");
HtmlForm form1 = (HtmlForm) UIHelper.findComponent("form1");
if (form1.isSubmitted())
firstResult = data2.getFirst();
int rowCount = DAOGeneric.getDataCount("User", "");
List rows = DAOGeneric.getPagedData("User", "", orderBy,
orderDirection, firstResult, perPage);
PagedListDataModel dataModel = new PagedListDataModel();
dataModel.setWrappedData(rows);
dataModel.setTotalNumRows(rowCount);
dataModel.setPageSize(perPage);
return dataModel;
}
...
}
<h:panelGroup>
<x:dataTable id="data2"
styleClass="table" headerClass="table_header"
var="user" value="#{UserCtl.userListDataModel}"
preserveDataModel="true"
rowClasses="row1,row2"
rows="25" >
<h:column>
<f:facet name="header">
<h:commandLink action="#{UserCtl.orderByName}">
<h:outputText id="orderbyname" value="#{fl.user_name}"/>
</h:commandLink>
</f:facet>
<h:outputText value="#{user.name}" styleClass="copy"/>
</h:column>
<h:column>
<f:facet name="header">
<h:commandLink action="#{UserCtl.orderByFirstName}">
<h:outputText id="orderbyfirstname" value="First Name"/>
</h:commandLink>
</f:facet>
<h:outputText value="#{user.firstname}" styleClass="copy"/>
</h:column>
<h:column>
<f:facet name="header">
<h:commandLink action="#{UserCtl.orderByLastName}">
<h:outputText id="orderbylastname" value="Last Name"/>
</h:commandLink>
</f:facet>
<h:outputText value="#{user.lastname}" styleClass="copy"/>
</h:column>
<h:column>
<f:facet name="header">
<h:commandLink action="#{UserCtl.orderByEmail}">
<h:outputText id="orderbyemail" value="Email"/>
</h:commandLink>
</f:facet>
<h:outputText value="#{user.email}" styleClass="copy"/>
</h:column>
<h:column>
<f:facet name="header">
<h:outputText value="Action"/>
</f:facet>
<h:commandLink id="edit" action="#{UserCtl.updateUserPage}" value="edit"
styleClass="copy"/>
<h:outputText value=" | " styleClass="copy"/>
<h:commandLink id="delete" action="#{UserCtl.deleteUserPage}"
value="delete" styleClass="copy"/>
</h:column>
</x:dataTable>
<h:panelGrid columns="1" styleClass="table3">
<x:dataScroller id="ds2"
for="data2"
paginator="true"
paginatorMaxPages="9"
paginatorTableClass="paginator"
paginatorActiveColumnStyle="font-weight:bold;"
fastStep="10">
<f:facet name="first">
<h:graphicImage url="images/arrow-first.gif" styleClass="button" />
</f:facet>
<f:facet name="last">
<h:graphicImage url="images/arrow-last.gif" styleClass="button" />
</f:facet>
<f:facet name="previous">
<h:graphicImage url="images/arrow-previous.gif" styleClass="button" />
</f:facet>
<f:facet name="next">
<h:graphicImage url="images/arrow-next.gif" styleClass="button" />
</f:facet>
<f:facet name="fastforward">
<h:graphicImage url="images/arrow-ff.gif" styleClass="button" />
</f:facet>
<f:facet name="fastrewind">
<h:graphicImage url="images/arrow-fr.gif" styleClass="button" />
</f:facet>
</x:dataScroller>
<x:dataScroller
for="data2"
pageCountVar="pageCount"
pageIndexVar="pageIndex">
<h:outputFormat value="#{controls['dataScroller_pages']}"
styleClass="copy" >
<f:param value="#{pageIndex}" />
<f:param value="#{pageCount}" />
</h:outputFormat>
</x:dataScroller>
</h:panelGrid>
</h:panelGroup>
import java.util.List;
import javax.faces.model.DataModel;
public class PagedListDataModel extends DataModel {
private int rowIndex = -1;
private int totalNumRows;
private int pageSize;
private List list;
public PagedListDataModel() {
super();
}
public PagedListDataModel(List list, int totalNumRows, int pageSize) {
super();
setWrappedData(list);
this.totalNumRows = totalNumRows;
this.pageSize = pageSize;
}
public boolean isRowAvailable() {
if (list == null)
return false;
int rowIndex = getRowIndex();
if (rowIndex >= 0 && rowIndex < list.size())
return true;
else
return false;
}
public int getRowCount() {
return totalNumRows;
}
public Object getRowData() {
if (list == null)
return null;
else if (!isRowAvailable())
throw new IllegalArgumentException();
else {
int dataIndex = getRowIndex();
return list.get(dataIndex);
}
}
public int getRowIndex() {
return (rowIndex % pageSize);
}
public void setRowIndex(int rowIndex) {
this.rowIndex = rowIndex;
}
public Object getWrappedData() {
return list;
}
public void setWrappedData(Object list) {
this.list = (List) list;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
public int getTotalNumRows() {
return totalNumRows;
}
public void setTotalNumRows(int totalNumRows) {
this.totalNumRows = totalNumRows;
}
}
