I have this JSF backing bean method:
public void filterProductsByCategory()
{
filtered = true;
products = controller.obtainProductListByCategory(selectedDesiredCategory);
showMessage("Filtered by selected category");
}
Which calls the obtainProductListByCategory method. This returns a list of products. When it is time to refresh the JSF page (it access the getters for the variables it needs), it enters the getter here:
public List<Product> getProducts()
{
if(filtered)
{
filtered = false;
return products;
}
products = controller.obtainProductList();
return products;
}
The obtainProductList retrieves all the products in the database. My application is a webmarket and what I'm trying to do is to first: get all the products displayed (which is working fine), then: sort by category (there's the problem). For some reason even after the last method enters the if statement and returns, it goes back inside, with the variable filtered false and proceeds with the method.
I found out through debugging that this code seems to execute everytime too (Located in Method.java):
public Object invoke(Object obj, Object... args)
throws IllegalAccessException, IllegalArgumentException,
InvocationTargetException
{
if (!override) {
if (!Reflection.quickCheckMemberAccess(clazz, modifiers)) {
Class<?> caller = Reflection.getCallerClass(1);
checkAccess(caller, clazz, obj, modifiers);
}
}
MethodAccessor ma = methodAccessor; // read volatile
if (ma == null) {
ma = acquireMethodAccessor();
}
return ma.invoke(obj, args);
}
Curious enough, the above loop I mentioned is repeated for as many products exist in my List the first time I retrieve all the objects (all the objects in my database). In the end the web page gets all the products back again, even when I tried to filter the results in my datatable What is going on here?
Related
Say I have this piece of code
<p:dataTable styleClass="scheduleTable" value="#{todaySchedule.hours}" var="hour">
<p:column headerText="Hour" styleClass="hourColumn" >
#{hour.time}
</p:column>
</p:dataTable>
and in a class called todaySchedule, have a method
public List<Hour> getHours() {
final List<Hour> hours = IntStream.range(0, Hour.TIME.values().length)
.mapToObj($ -> new Hour()).collect(Collectors.toList());
for (int i = 0; i < 5; i++) {
hours.get(i).setHour(1);
}
return hours;
}
and here's the Hour class
public class Hour {
private int time;
public int getTime() {
return time;
}
public void setTime(int time) {
this.time = time;
}
}
Now, I'm not sure what JSF does behind the scenes to make this dynamic dataTable data iteration through the hours List possible, but I assume that if this is happening all in one thread, then it is okay. However, what if behind the scenes, the getHours is used in another thread that actually does the generating columns and see Hour in a bad state? This could be avoided if the getHours() method was
public List<Hour> getHours() {
final List<Hour> hours = new ArrayList<>();
for (int i = 0; i < 5; i++) {
hours.add(new Hour(i + ""));
}
return hours;
}
with the corresponding Hour class being
public class Hour {
private final int time;
public Hour(int time) {
this.time = time;
}
public int getTime() {
return time;
}
}
However, my question is that, if it wasn't changed to the latter design, can things go wrong when using basic dynamic JSF dataTable rendering due to visibility issues in Java when publishing this Hour instances?
JSF runs on top of Servlet API which serves one request in one thread, so unless you introduce more threads yourself you may expect your code to be run in a single thread.
On the other hand, you should get to know the basics of JSF life-cycle and how the bean properties are being accessed as this may cause you a lot of troubles if you don't understand it.
For example, should your Java code stay the same, adding another reference to todaySchedule.hours to your JSF would cause the getter to be called twice, thus generating the content twice. This can get really messy very quickly, so it is a good thing to do some "caching". I personally use this approach:
private List<Hour> hours = null;
private void initHours() {
this.hours = new LinkedList<>();
// Fill hours here
}
public List<Hour> getHours() {
if (this.hours == null) {
initHours();
}
return this.hours;
}
You have to be careful though at what stage of the JSF lifecycle you do this. Should you for example in a form processing method change the data affecting the list generation, the list will probably be already "cached" from the restore-view phase and the change would not be reflected when render-view phase starts. In such case you should be aware of the caching and clear the list when you need to reload it.
public void saveHours() {
// Save the data, do whatever you need to do
// This will ensure re-initializing the list on the next call
this.hours = null;
}
I have an Xpage application that uses the extension library where the xsp.extlib.convstate is 'null' for one of three users until they manually refresh page. All three users access application via RDP using Citrix and internet options are the same for all three. Trying to figure out why this would be happening. The application is only on one 9.0.1 server.
From the looks of the source code, if there hasn't been a conversationState initialised yet, the conversationState would not be initialised until either:
after the Render Response phase (in the phase listener: com.ibm.xsp.extlib.component.layout.impl.ApplicationPhaseListener)
#SuppressWarnings("unchecked") // $NON-NLS-1$
public void afterPhase(PhaseEvent event) {
if(event.getPhaseId()==PhaseId.RENDER_RESPONSE) {
// After the render phase, we save the conversion state
ConversationState.saveInSession(event.getFacesContext());
}
}
in the setParent method of the UIApplicationLayout, and this seems to be guarded by a 'isRestoringState' condition, which means I don't think this would run on the first view of a page as there wouldn't be any state to restore.
#Override
public void setParent(UIComponent parent) {
super.setParent(parent);
if( null == parent ){ // removing parent
return;
}
// TODO should move this initialization to initBeforeContents instead
FacesContextEx context = (FacesContextEx) getFacesContext();
if(null != context && !context.isRestoringState()) {
ConversationState cs = ConversationState.get(context, FacesUtil.getViewRoot(this), true);
// Initialize the conversation state
// Set the current navigation path to the UserBean
ApplicationConfiguration conf = findConfiguration();
if(conf!=null) {
String navPath = conf.getNavigationPath();
if(StringUtil.isEmpty(navPath)) {
// If there isn't a navigation path that is defined, the use the default one
if(StringUtil.isEmpty(cs.getNavigationPath())) {
navPath = conf.getDefaultNavigationPath();
}
}
if(StringUtil.isNotEmpty(navPath)) {
cs.setNavigationPath(navPath);
}
}
}
}
So this might explain why it wouldn't be initialised until the 2nd page view.
You could try forcing an initialisation of the ConversationState before you try to use it, maybe in beforePageLoad, by calling one of the com.ibm.xsp.extlib.component.layout.ConversationState's get() methods.
Note the boolean parameter tells the method to create the ConversationState if it does not exist.
I don't do much ServerSide Javascript but I guess this works? The sentiment is correct.
#{javascript: com.ibm.xsp.extlib.component.layout.ConversationState.get(facesContext, true); }
If you are doing it in java then:
ConversationState.get(FacesContext.getInstance(), true);
Does this sound like an explanation of why you are seeing your behaviour?
I have 3 test web applications, using the same model and controllers, the difference is in JSF session managed beans.
The applications A and C use JSF DataModel to retrieve items :
A JPA Query result set returns a java LIST which is then wrapped in a ListDataModel. The value of this latter is being the items displayed by PrimeFaces dataTable.
The application B uses Java LIST to retrieve items:
A JPA Query result set returns a java List which is being the value of items displayed by PrimeFaces 2.2.1 dataTable.
Sorting and filtering in application B are fully functional and fast, while in application A and C, they are deadly not.
I just want to mention that Filtering in Sorting of other Libraries like Richfaces, OpenFaces, works out of the box using this same code.
The problem also remains in PrimeFaces 3.0.0. Is this a bug?
In App B :
Code:
private List<Customer> items = null;
// remainder of code here
public List<Customer> getCustomerItems() {
if (customerItems == null) {
getPagingInfo();
customerItems = jpaController.findCustomerEntities(pagingInfo.getBatchSize(), pagingInfo.getFirstItem());
}
return customerItems;
}
In App A:
Code:
private DataModel items = null;
public PaginationHelper getPagination() {
if (pagination == null) {
pagination = new PaginationHelper(999999) {
#Override
public int getItemsCount() {
return getJpaController().getChimioCount();
}
#Override // The list of Customers is wrapped in a JSF ListDataModel
public DataModel createPageDataModel() {
return new ListDataModel(getJpaController().findCustomerEntities(getPageSize(), getPageFirstItem()));
}
};
}
return pagination;
}
/**
* this goes for the value attribute in a datatable to list all the Customer items
*/
public DataModel getItems() {
if (items == null) {
items = getPagination().createPageDataModel();
}
return items;
}
In App C:
Code:
private DataModel<Project> items;
// remainder of code here
/**
*The ListDataModel is initialized here
*/
public void init() {
try {
setProjectList(doInTransaction(new PersistenceAction<List<Project>>() {
public List<Project> execute(EntityManager em) {
Query query = em.createNamedQuery("project.getAll");
return (List<Project>) query.getResultList();
}
}));
} catch (ManagerException ex) {
Logger.getLogger(ProjectManager.class.getName()).log(Level.SEVERE, null, ex);
}
projectItems = new LinkedList<SelectItem>();
projectItems.add(new SelectItem(new Project(), "-- Select one project --"));
if (getProjectList() != null) {
projects = new ListDataModel<Project>(getProjectList());
for (Project p : getProjectList()) {
projectItems.add(new SelectItem(p, p.getName()));
}
}
}
Thank you in advance for your help.
This might be a PrimeFaces bug. I have seen some discussion about issues with DataTable sorting when a data model is used. Here is a link to one of the PrimeFaces defects in their tracker.
If I create a List based on an array of Commands, and the text of some Commands are not entirely shown in the List, although the List preferredWidth is set to the Form preferredWidth, how to ticker them ?
Thank you very much
Add the below class in your midlet class or create a new class file for that:
class TickerRenderer extends DefaultListCellRenderer {
private DefaultListCellRenderer selectedRenderer = new DefaultListCellRenderer(false);
private List parentList;
public TickerRenderer() {
super(false);
}
public boolean animate() {
if (parentList != null && parentList.getComponentForm() != null) {
if (selectedRenderer.isTickerRunning()) {
if (selectedRenderer.animate()) {
parentList.repaint();
}
}
}
return super.animate();
}
public Component getListCellRendererComponent(List list, Object value, int index, boolean isSelected) {
if (isSelected) {
selectedRenderer.getListCellRendererComponent(list, value, index, isSelected);
// sometimes the list asks for a dummy selected value for size calculations and this might
// break the tickering state
if (index == list.getSelectedIndex()) {
if (selectedRenderer.shouldTickerStart()) {
if (!selectedRenderer.isTickerRunning()) {
parentList = list;
list.getComponentForm().registerAnimated(this);
selectedRenderer.startTicker(UIManager.getInstance().getLookAndFeel().getTickerSpeed(), true);
}
} else {
if (selectedRenderer.isTickerRunning()) {
selectedRenderer.stopTicker();
}
}
}
return selectedRenderer;
} else {
return super.getListCellRendererComponent(list, value, index, isSelected);
}
}
}
Use it like this:
List cmdList = new List(cmds);
cmdList.setListCellRenderer(new TickerRenderer());
Try this code, it will show list in dialog box on clicking "Show list" command and will also enable ticker initially. Below is the code which shows how to use the above mentioned class to see ticker in list when list is contained in dialog.
Don't forget to make your list final so that it can be used in inner classes.
form.addCommand(new Command("Show list") { // add command in form and override its actionPerformed method
public void actionPerformed(ActionEvent evt) {
Dialog d = new Dialog() { // create an instance of dialog and make it an inner class so that you can override onShow() method and set focus on list when dialog gets initialized and also can set its index to ur preferred one (here it's 0)
protected void onShow() { // overriding of onShow() method
list.requestFocus(); // set focus on list
list.setSelectedIndex(0); // set selected index to 0
}
};
d.addComponent(list); // add list in dialog
d.show(); // show dialog
}
});
This code shows my list in dialog and starts ticker initially. If it doesn't help, post your code, i will try to see it.
I have several tables in my database that have read-only fields that get set on Inserting and Updating, namely: AddDate (DateTime), AddUserName (string), LastModDate (DateTime), LastModUserName (string).
All of the tables that have these values have been set to inherit from the following interface:
public interface IUserTrackTable
{
string AddUserName { get; set; }
DateTime AddDate { get; set; }
string LastModUserName { get; set; }
DateTime LastModDate { get; set; }
}
As such, I have the following method on the Edit.aspx page:
protected void DetailsDataSource_Updating(object sender, LinqDataSourceUpdateEventArgs e)
{
IUserTrackTable newObject = e.NewObject as IUserTrackTable;
if (newObject != null)
{
newObject.LastModUserName = User.Identity.Name;
newObject.LastModDate = DateTime.Now;
}
}
However, by the time it hits this method, the e.OriginalObject has already lost the values for all four fields, so a ChangeConflictException gets thrown during the actual Update. I have tried adding the four column names to the DetailsView1.DataKeyNames array in the Init event handler:
protected void Page_Init(object sender, EventArgs e)
{
// other things happen before this
var readOnlyColumns = table.Columns.Where(c => c.Attributes.SingleOrDefaultOfType<ReadOnlyAttribute>(ReadOnlyAttribute.Default).IsReadOnly).Select(c => c.Name);
DetailsView1.DataKeyNames = DetailsView1.DataKeyNames.Union<string>(readOnlyColumns).ToArray<string>();
DetailsView1.RowsGenerator = new CustomFieldGenerator(table, PageTemplates.Edit, false);
// other things happen after this
}
I've tried making that code only happen on PostBack, and still nothing. I'm at a lose for how to get the values for all of the columns to make the round-trip.
The only thing the CustomFieldGenerator is handling the ReadOnlyAttribute, following the details on C# Bits.
UPDATE: After further investigation, the values make the round trip to the DetailsView_ItemUpdating event. All of the values are present in the e.OldValues dictionary. However, they are lost by the time it gets to the LinqDataSource_Updating event.
Obviously, there are the "solutions" of making those columns not participate in Concurrency Checks or other ways that involve hard-coding, but the ideal solution would dynamically add the appropriate information where needed so that this stays as a Dynamic solution.
i Drovani, I assume you want data auditing (see Steve Sheldon's A Method to Handle Audit Fields in LINQ to SQL), I would do this in the model in EF4 you can do it like this:
partial void OnContextCreated()
{
// Register the handler for the SavingChanges event.
this.SavingChanges += new EventHandler(context_SavingChanges);
}
private static void context_SavingChanges(object sender, EventArgs e)
{
// handle auditing
AuditingHelperUtility.ProcessAuditFields(objects.GetObjectStateEntries(EntityState.Added));
AuditingHelperUtility.ProcessAuditFields(objects.GetObjectStateEntries(EntityState.Modified), InsertMode: false);
}
internal static class AuditingHelperUtility
{
internal static void ProcessAuditFields(IEnumerable<Object> list, bool InsertMode = true)
{
foreach (var item in list)
{
IAuditable entity = item as IAuditable;
if (entity != null)
{
if (InsertMode)
{
entity.InsertedBy = GetUserId();
entity.InsertedOn = DateTime.Now;
}
entity.UpdatedBy = GetUserId();
entity.UpdatedOn = DateTime.Now;
}
}
}
}
Sadly this is not possible with EF v1