Richfaces Datascroler, EntityQuery and pagination
Last time i was trying to use rich:dataTable, rich:datascroller with large tables and I want to use for this EntityQuery and do some pagination.
I asume that i need some custom DataModel extending org.ajax4jsf.model.ExtendedDataModel (thanks to this post 'Here is a Richfaces Ajax Datascroler and Seam Example'.
So here it is - my solution:
import java.io.IOException;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.faces.context.FacesContext;
import org.ajax4jsf.model.DataVisitor;
import org.ajax4jsf.model.ExtendedDataModel;
import org.ajax4jsf.model.Range;
import org.ajax4jsf.model.SequenceRange;
import org.jboss.seam.framework.EntityQuery;
import pl.xxx.model.AbstractEntity;
public abstract class EntityDataModel<T extends AbstractEntity, ID extends Serializable> extends ExtendedDataModel {
private static final String ID_METHOD_NAME = "getId";
private EntityQuery entityQuery;
private Class<T> entityClass;
private ID currentId;
private Map<ID, T> wrappedData = new HashMap<ID, T>();
private List<ID> wrappedKeys;
public EntityDataModel() {
//entityClass = (Class<T>)((ParameterizedType)getClass().getGenericSuperclass()).getActualTypeArguments()[0];
Class clazz = getClass();
while(!(clazz.getGenericSuperclass() instanceof ParameterizedType)) {
clazz = clazz.getSuperclass();
}
entityClass = (Class<T>) ((ParameterizedType)clazz.getGenericSuperclass()).getActualTypeArguments()[0];
}
public void setEntityQuery(EntityQuery entityQuery) {
this.entityQuery = entityQuery;
}
@Override
public Object getRowKey() {
return currentId;
}
/*
* This method normally called by Visitor before request Data Row.
*/
@Override
public void setRowKey(Object key) {
currentId = (ID)key;
}
@Override
public void walk(FacesContext fCtx, DataVisitor visitor, Range range, Object argument)
throws IOException {
int firstResult = ((SequenceRange)range).getFirstRow();
int maxResults = ((SequenceRange)range).getRows();
entityQuery.setFirstResult(firstResult);
entityQuery.setMaxResults(maxResults);
List<T> list = entityQuery.getResultList();
wrappedKeys = new ArrayList<ID>();
wrappedData = new HashMap<ID, T>();
for (T row : list) {
ID id = getId(row);
wrappedKeys.add(id);
wrappedData.put(id, row);
visitor.process(fCtx, id, argument);
}
}
@Override
public int getRowCount() {
return entityQuery.getResultCount().intValue();
}
@Override
public Object getRowData() {
if (currentId == null) {
return null;
} else {
T ret = wrappedData.get(currentId);
if (ret == null) {
ret = (T)entityQuery.getEntityManager().find(entityClass, currentId);
wrappedData.put(currentId, ret);
return ret;
} else {
return ret;
}
}
}
@Override
public int getRowIndex() {
return 0;
}
/**
* Unused rudiment from old JSF staff.
*/
@Override
public Object getWrappedData() {
throw new UnsupportedOperationException();
}
@Override
public boolean isRowAvailable() {
if (currentId == null) {
return false;
} else {
for (T row : (List<T>)entityQuery.getResultList()) {
ID rowId = getId(row);
if (rowId.equals(currentId)) {
return true;
}
}
return false;
}
}
/**
* Unused rudiment from old JSF staff.
*/
@Override
public void setRowIndex(int newRowIndex) { }
/**
* Unused rudiment from old JSF staff.
*/
@Override
public void setWrappedData(Object data) {
throw new UnsupportedOperationException();
}
private ID getId(T row) {
ID id;
try {
Method idMethod = row.getClass().getMethod(ID_METHOD_NAME, new Class[0]);
Class<?> idType = idMethod.getReturnType();
id = (ID)idMethod.invoke(row, new Object[0]);
} catch (Exception e) {
throw new javax.faces.FacesException("Failed to obtain row id", e);
}
return id;
}
}Next can use this abstrac EntityDataModel for our custom entity data model like this:
import org.jboss.seam.annotations.Create;
import org.jboss.seam.annotations.In;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.framework.EntityQuery;
import pl.xxx.model.User;
@Name("userList")
public class UserDataModel extends EntityDataModel<User, Long> {
@In(create=true)
private EntityQuery users;
@Create
public void create() {
setEntityQuery(users);
}
}In components.xml we need to define our EntityQuery:
<fwk:entity-query name="users" entity-manager="#{em}"
ejbql="select u from User u"
order="u.username"
max-results="10">
<fwk:restrictions>
<value>lower(u.username) like lower('%' || #{exampleUser.username})</value>
<value>lower(u.lastName) like lower('%' || #{exampleUser.lastName})</value>
</fwk:restrictions>
</fwk:entity-query>
<component name="exampleUser" class="pl.xxx.model.User" scope="session"/>Now the users.xhtml:
<rich:panel header="#{messages['userList.header']}">
<h:form>
<h:outputLabel value="Filter by username" for="username"></h:outputLabel>
<h:inputText id="username" value="#{exampleUser.username}">
<a4j:support reRender="userList" event="onkeyup" requestDelay="1" />
</h:inputText>
<a4j:status>
<f:facet name="start"><h:graphicImage value="/img/spinner.gif" /></f:facet>
</a4j:status>
</h:form>
<h:form>
<rich:dataTable id="userList" value="#{userList}" var="user" rows="10">
<rich:column>
<f:facet name="header">#{messages['user.username']}</f:facet>
<s:link action="user">
<h:outputText value="#{user.username}" />
<f:param name="uid" value="#{user.id}" />
</s:link>
</rich:column>
<rich:column>
<f:facet name="header">#{messages['user.firstName']}</f:facet>
<h:outputText value="#{user.firstName}"/>
</rich:column>
<rich:column>
<f:facet name="header">#{messages['user.lastName']}</f:facet>
<h:outputText value="#{user.lastName}"/>
</rich:column>
<rich:column>
<f:facet name="header">#{messages['user.email']}</f:facet>
<h:outputText value="#{user.email}"/>
</rich:column>
<f:facet name="footer">
<rich:datascroller/>
</f:facet>
</rich:dataTable>
</h:form>
<div class="actionButtons">
<s:button action="user" value="#{messages['button.add']}">
<f:param name="uid" value=""/>
</s:button>
</div>
</rich:panel>I also use some ajax support for filtering data but there is one problem. Suppose i have shown all users and i'm on the last page. After doing some filtering datascroller is not reacting properly on the data range change. I don't know how to fix this.
What do you think about this solution?
Jarek
