I've an entity that contains a org.joda.time.Minutes field. I want to use that field in one of my <h:selectOneMenu> components as a label:
<h:selectOneMenu value="#{manager.spec}"
converter="omnifaces.SelectItemsIndexConverter">
<f:selectItem itemLabel="#{msg.choose_one}" />
<f:selectItems value="#{allSpecs}" var="spec"
itemLabel="#{f.print(spec.timeout.toStandardDuration().toPeriod())}" />
</h:selectOneMenu>
With f (just a demo name, obviously) being:
#Named("f")
#RequestScoped
public class UserPeriodFormatter {
private PeriodFormatter printer;
#PostConstruct
public void init() {
printer = PeriodFormat.wordBased(Faces.getLocale());
}
public String print(ReadablePeriod period) {
return printer.print(period);
}
}
This prints, eg. 5 minutes, 1 hour and 10 minutes or 3 months, 2 hours and 5 minutes, using words from the user's locale.
My question is simply: is there a better way to do this? I tried a simple Producer method for the formatter, but since PeriodFormatter doesn't expose a no-arg constructor this won't fly with CDI.
Bonus question: could this be a nice addition to the omnifaces' dates functions?
Related
I am creating a web application, where you have to read a list of objects / entities from a DB and populate it in a JSF <h:selectOneMenu>. I am unable to code this. Can someone show me how to do it?
I know how to get a List<User> from the DB. What I need to know is, how to populate this list in a <h:selectOneMenu>.
<h:selectOneMenu value="#{bean.name}">
...?
</h:selectOneMenu>
Based on your question history, you're using JSF 2.x. So, here's a JSF 2.x targeted answer. In JSF 1.x you would be forced to wrap item values/labels in ugly SelectItem instances. This is fortunately not needed anymore in JSF 2.x.
Basic example
To answer your question directly, just use <f:selectItems> whose value points to a List<T> property which you preserve from the DB during bean's (post)construction. Here's a basic kickoff example assuming that T actually represents a String.
<h:selectOneMenu value="#{bean.name}">
<f:selectItems value="#{bean.names}" />
</h:selectOneMenu>
with
#ManagedBean
#RequestScoped
public class Bean {
private String name;
private List<String> names;
#EJB
private NameService nameService;
#PostConstruct
public void init() {
names = nameService.list();
}
// ... (getters, setters, etc)
}
Simple as that. Actually, the T's toString() will be used to represent both the dropdown item label and value. So, when you're instead of List<String> using a list of complex objects like List<SomeEntity> and you haven't overridden the class' toString() method, then you would see com.example.SomeEntity#hashcode as item values. See next section how to solve it properly.
Also note that the bean for <f:selectItems> value does not necessarily need to be the same bean as the bean for <h:selectOneMenu> value. This is useful whenever the values are actually applicationwide constants which you just have to load only once during application's startup. You could then just make it a property of an application scoped bean.
<h:selectOneMenu value="#{bean.name}">
<f:selectItems value="#{data.names}" />
</h:selectOneMenu>
Complex objects as available items
Whenever T concerns a complex object (a javabean), such as User which has a String property of name, then you could use the var attribute to get hold of the iteration variable which you in turn can use in itemValue and/or itemLabel attribtues (if you omit the itemLabel, then the label becomes the same as the value).
Example #1:
<h:selectOneMenu value="#{bean.userName}">
<f:selectItems value="#{bean.users}" var="user" itemValue="#{user.name}" />
</h:selectOneMenu>
with
private String userName;
private List<User> users;
#EJB
private UserService userService;
#PostConstruct
public void init() {
users = userService.list();
}
// ... (getters, setters, etc)
Or when it has a Long property id which you would rather like to set as item value:
Example #2:
<h:selectOneMenu value="#{bean.userId}">
<f:selectItems value="#{bean.users}" var="user" itemValue="#{user.id}" itemLabel="#{user.name}" />
</h:selectOneMenu>
with
private Long userId;
private List<User> users;
// ... (the same as in previous bean example)
Complex object as selected item
Whenever you would like to set it to a T property in the bean as well and T represents an User, then you would need to bake a custom Converter which converts between User and an unique string representation (which can be the id property). Do note that the itemValue must represent the complex object itself, exactly the type which needs to be set as selection component's value.
<h:selectOneMenu value="#{bean.user}" converter="#{userConverter}">
<f:selectItems value="#{bean.users}" var="user" itemValue="#{user}" itemLabel="#{user.name}" />
</h:selectOneMenu>
with
private User user;
private List<User> users;
// ... (the same as in previous bean example)
and
#ManagedBean
#RequestScoped
public class UserConverter implements Converter {
#EJB
private UserService userService;
#Override
public Object getAsObject(FacesContext context, UIComponent component, String submittedValue) {
if (submittedValue == null || submittedValue.isEmpty()) {
return null;
}
try {
return userService.find(Long.valueOf(submittedValue));
} catch (NumberFormatException e) {
throw new ConverterException(new FacesMessage(String.format("%s is not a valid User ID", submittedValue)), e);
}
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object modelValue) {
if (modelValue == null) {
return "";
}
if (modelValue instanceof User) {
return String.valueOf(((User) modelValue).getId());
} else {
throw new ConverterException(new FacesMessage(String.format("%s is not a valid User", modelValue)), e);
}
}
}
(please note that the Converter is a bit hacky in order to be able to inject an #EJB in a JSF converter; normally one would have annotated it as #FacesConverter(forClass=User.class), but that unfortunately doesn't allow #EJB injections)
Don't forget to make sure that the complex object class has equals() and hashCode() properly implemented, otherwise JSF will during render fail to show preselected item(s), and you'll on submit face Validation Error: Value is not valid.
public class User {
private Long id;
#Override
public boolean equals(Object other) {
return (other != null && getClass() == other.getClass() && id != null)
? id.equals(((User) other).id)
: (other == this);
}
#Override
public int hashCode() {
return (id != null)
? (getClass().hashCode() + id.hashCode())
: super.hashCode();
}
}
Complex objects with a generic converter
Head to this answer: Implement converters for entities with Java Generics.
Complex objects without a custom converter
The JSF utility library OmniFaces offers a special converter out the box which allows you to use complex objects in <h:selectOneMenu> without the need to create a custom converter. The SelectItemsConverter will simply do the conversion based on readily available items in <f:selectItem(s)>.
<h:selectOneMenu value="#{bean.user}" converter="omnifaces.SelectItemsConverter">
<f:selectItems value="#{bean.users}" var="user" itemValue="#{user}" itemLabel="#{user.name}" />
</h:selectOneMenu>
See also:
Our <h:selectOneMenu> wiki page
View-Page
<h:selectOneMenu id="selectOneCB" value="#{page.selectedName}">
<f:selectItems value="#{page.names}"/>
</h:selectOneMenu>
Backing-Bean
List<SelectItem> names = new ArrayList<SelectItem>();
//-- Populate list from database
names.add(new SelectItem(valueObject,"label"));
//-- setter/getter accessor methods for list
To display particular selected record, it must be one of the values in the list.
Roll-your-own generic converter for complex objects as selected item
The Balusc gives a very useful overview answer on this subject. But there is one alternative he does not present: The Roll-your-own generic converter that handles complex objects as the selected item. This is very complex to do if you want to handle all cases, but pretty simple for simple cases.
The code below contains an example of such a converter. It works in the same spirit as the OmniFaces SelectItemsConverter as it looks through the children of a component for UISelectItem(s) containing objects. The difference is that it only handles bindings to either simple collections of entity objects, or to strings. It does not handle item groups, collections of SelectItems, arrays and probably a lot of other things.
The entities that the component binds to must implement the IdObject interface. (This could be solved in other way, such as using toString.)
Note that the entities must implement equals in such a way that two entities with the same ID compares equal.
The only thing that you need to do to use it is to specify it as converter on the select component, bind to an entity property and a list of possible entities:
<h:selectOneMenu value="#{bean.user}" converter="selectListConverter">
<f:selectItem itemValue="unselected" itemLabel="Select user..."/>
<f:selectItem itemValue="empty" itemLabel="No user"/>
<f:selectItems value="#{bean.users}" var="user" itemValue="#{user}" itemLabel="#{user.name}" />
</h:selectOneMenu>
Converter:
/**
* A converter for select components (those that have select items as children).
*
* It convertes the selected value string into one of its element entities, thus allowing
* binding to complex objects.
*
* It only handles simple uses of select components, in which the value is a simple list of
* entities. No ItemGroups, arrays or other kinds of values.
*
* Items it binds to can be strings or implementations of the {#link IdObject} interface.
*/
#FacesConverter("selectListConverter")
public class SelectListConverter implements Converter {
public static interface IdObject {
public String getDisplayId();
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
if (value == null || value.isEmpty()) {
return null;
}
return component.getChildren().stream()
.flatMap(child -> getEntriesOfItem(child))
.filter(o -> value.equals(o instanceof IdObject ? ((IdObject) o).getDisplayId() : o))
.findAny().orElse(null);
}
/**
* Gets the values stored in a {#link UISelectItem} or a {#link UISelectItems}.
* For other components returns an empty stream.
*/
private Stream<?> getEntriesOfItem(UIComponent child) {
if (child instanceof UISelectItem) {
UISelectItem item = (UISelectItem) child;
if (!item.isNoSelectionOption()) {
return Stream.of(item.getValue());
}
} else if (child instanceof UISelectItems) {
Object value = ((UISelectItems) child).getValue();
if (value instanceof Collection) {
return ((Collection<?>) value).stream();
} else {
throw new IllegalStateException("Unsupported value of UISelectItems: " + value);
}
}
return Stream.empty();
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
if (value == null) return null;
if (value instanceof String) return (String) value;
if (value instanceof IdObject) return ((IdObject) value).getDisplayId();
throw new IllegalArgumentException("Unexpected value type");
}
}
I'm doing it like this:
Models are ViewScoped
converter:
#Named
#ViewScoped
public class ViewScopedFacesConverter implements Converter, Serializable
{
private static final long serialVersionUID = 1L;
private Map<String, Object> converterMap;
#PostConstruct
void postConstruct(){
converterMap = new HashMap<>();
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object object) {
String selectItemValue = String.valueOf( object.hashCode() );
converterMap.put( selectItemValue, object );
return selectItemValue;
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String selectItemValue){
return converterMap.get(selectItemValue);
}
}
and bind to component with:
<f:converter binding="#{viewScopedFacesConverter}" />
If you will use entity id rather than hashCode you can hit a collision- if you have few lists on one page for different entities (classes) with the same id
Call me lazy but coding a Converter seems like a lot of unnecessary work. I'm using Primefaces and, not having used a plain vanilla JSF2 listbox or dropdown menu before, I just assumed (being lazy) that the widget could handle complex objects, i.e. pass the selected object as is to its corresponding getter/setter like so many other widgets do. I was disappointed to find (after hours of head scratching) that this capability does not exist for this widget type without a Converter. In fact if you supply a setter for the complex object rather than for a String, it fails silently (simply doesn't call the setter, no Exception, no JS error), and I spent a ton of time going through BalusC's excellent troubleshooting tool to find the cause, to no avail since none of those suggestions applied. My conclusion: listbox/menu widget needs adapting that other JSF2 widgets do not. This seems misleading and prone to leading the uninformed developer like myself down a rabbit hole.
In the end I resisted coding a Converter and found through trial and error that if you set the widget value to a complex object, e.g.:
<p:selectOneListbox id="adminEvents" value="#{testBean.selectedEvent}">
... when the user selects an item, the widget can call a String setter for that object, e.g. setSelectedThing(String thingString) {...}, and the String passed is a JSON String representing the Thing object. I can parse it to determine which object was selected. This feels a little like a hack, but less of a hack than a Converter.
There is p:dataTable with p:inputText in a column:
<h:form id="form">
<p:dataTable id="dataTable" value="#{rowReorder.dataList}"
var="row" draggableRows="true" rowKey="#{row.id}">
<p:ajax event="rowReorder" listener="#{rowReorder.reorder}" update="dataTable"/>
<p:column>
<f:facet name="header">
<p:commandButton value="Add" actionListener="#{rowReorder.addData}"
update="dataTable" process="dataTable"/>
</f:facet>
<p:outputLabel value="#{row.id}"/>
</p:column>
<p:column>
<p:inputText value="#{row.name}"/>
</p:column>
</p:dataTable>
</h:form>
Backing bean:
import org.omnifaces.cdi.ViewScoped;
import org.primefaces.event.ReorderEvent;
import javax.inject.Named;
import java.io.Serializable;
import java.util.LinkedList;
import java.util.List;
#Named("rowReorder")
#ViewScoped
public class RowReorder implements Serializable {
private List<Data> dataList = new LinkedList<>();
public void addData() {
Data data = new Data();
data.setId(dataList.size() + 1);
data.setName("Data " + data.getId());
dataList.add(data);
}
public void reorder(ReorderEvent event) {
}
/**
* Getters, Setters
*/
public List<Data> getDataList() {
return dataList;
}
}
Data class:
public class Data implements Serializable {
private Integer id;
private String name;
/**
* Getters, Setters
*/
}
Sample datatable before reordering:
--------------
|id | name |
--------------
| 1 | Data 1 |
| 2 | Data 2 |
| 3 | Data 3 |
| 4 | Data 4 |
--------------
and after reordering (moving 1-st row to 3-rd):
--------------
|id | name |
--------------
| 2 | Data 1 |
| 3 | Data 2 |
| 1 | Data 3 |
| 4 | Data 4 |
--------------
I understand that it is happening 'cause of setting data from p:inputText's at UPDATE_MODEL phase. I tried to prevent processing of input fields by specifying process="#none" in p:ajax component, but it doesn't work. Have any idea how to make draggableRows and p:inputText friends?
First solution
I found a solution!
It does not processing inputs (and actually does not submit it at all) with attributes process="#none" partialSubmit="true"
So complete p:ajax component looks like
<p:ajax event="rowReorder" listener="#{rowReorder.reorder}" update="dataTable" process="#none" partialSubmit="true"/>
Second solution (if submitted data is needed)
Theory:
Lets check out what is happening on dragging row?
We have ajax request forcing process="form:dataTable". On APPLY_REQUEST_VALUES phase DataTableRenderer tries to invoke decode of DraggableRowsFeature which, in turn, rotating list elements (list that specified as dataTable's value attribute). So on UPDATE_MODEL_VALUES phase we have a rotated list, and input components, which wants to submit their values to name fields of Data objects. But request parameters still contains old row indexes in input ids: they are form:dataTable:1:name = Data 2, form:dataTable:2:name = Data 3, form:dataTable:0:name = Data 1 (i added 3 rows, and moved first row to last). So here we getting what we got. In this way if we need data to be submitted on right places we have to prevent our list rotating before UPDATE_MODEL_VALUES is done,
and perform this rotation later on INVOKE_APPLICATION phase, and render dataTable on that ajax request:
In DraggableRowsFeature.decode() we can see that Collections.rotate() is calling only when value is instance of List.
if (value instanceof List) {
List list = (List) value;
if(toIndex >= fromIndex) {
Collections.rotate(list.subList(fromIndex, toIndex + 1), -1);
}
else {
Collections.rotate(list.subList(toIndex, fromIndex + 1), 1);
}
}
else {
LOGGER.info("Row reordering is only available for list backed datatables, use rowReorder ajax behavior with listener for manual handling of model update.");
}
Also there is DraggableRowsFeature.shouldDecode() method.
public boolean shouldDecode(FacesContext context, DataTable table) {
return context.getExternalContext().getRequestParameterMap().containsKey(table.getClientId(context) + "_rowreorder");
}
So here we have 2 possibilities to prevent datasource rotating:
Don't use List as dataTable value
Create own org.primefaces.component.datatable.feature.DraggableRowsFeature returning false in shouldDecode() method.
Practice:
I modified bean file like this:
#Named("rowReorder")
#ViewScoped
public class RowReorder implements Serializable {
private static final Logger log = LoggerFactory.getLogger(RowReorder.class);
private Set<Data> dataList = new LinkedHashSet<>();
public void addData() {
Data data = new Data();
data.setId(dataList.size() + 1);
data.setName("Data " + data.getId());
dataList.add(data);
log.warn("{} {}", Integer.toHexString(data.hashCode()), data.getId());
}
public void removeData(Data data) {
dataList.remove(data);
}
public void reorder(ReorderEvent event) {
List<Data> list = new LinkedList<>(dataList);
int fromIndex = event.getFromIndex();
int toIndex = event.getToIndex();
if(toIndex >= fromIndex) {
Collections.rotate(list.subList(fromIndex, toIndex + 1), -1);
}
else {
Collections.rotate(list.subList(toIndex, fromIndex + 1), 1);
}
dataList.clear();
dataList.addAll(list);
}
/**
* Getters, Setters
*/
public Set<Data> getDataList() {
return dataList;
}
}
And now it firstly submitting values to model and rotating list on INVOKE_APPLICATION phase.
The secret is the attribute rowStatePreserved of your datatable, add it:
rowStatePreserved="true"
<p:dataTable id="dataTable" value="#{rowReorder.dataList}"
var="row" draggableRows="true" rowKey="#{row.id}"
rowStatePreserved="true">
And keep this code as like:
<p:ajax event="rowReorder" listener="#{rowReorder.reorder}" update="dataTable" process="#this"/>
In my case i was used a combobox into datatable column, and after i added this atrribute the value do not change more than one row to another when i used draggableRows function.
I wait help you.
Other simple solution is to disable the inputs on the start of rowReorder:
<p:ajax event="rowReorder"
onstart="$(':input', PrimeFaces.escapeClientId('#{component.clientId}')).prop('disabled',true)"
update="#this"/>
Note that #{component.clientId} will return the client ID of the data table.
To avoid loosing data, you can Ajaxify the inputs:
<p:column headerText="#{msg.value}">
<p:inputText value="#{item.value}">
<p:ajax/>
</p:inputText>
</p:column>
i have two oneSelectMenu loaded with default values based on login Details,then second selectonemenu should load value based on first selectonemenu's onchangeEvent menu.i tried to clear the default value before onchange event but the value remains and doesn't work with onchange event.
<h:selectOneMenu id="blS" value="#{BoardAction.serviceAreaId}" >
<f:ajax event="valueChange" render="blSearchFacilityInput" listener="#{BoardAction.svaValueChangeEvent}"/>
<f:selectItems value="#{BoardAction.serviceAreaList}" var="c" itemLabel="#{c.svaCode}" itemValue="#{c.id}"/> </h:selectOneMenu>
<h:selectOneMenu id="blSearchFacilityInput" value="#{BoardAction.facilityId}"> <f:ajax event="valueChange" render="blSearchSectorInput" listener="#{BoardAction.facValueChangeEvent}"/>
<f:selectItems value="#{BoardAction.svaFaciltyList}" var="c" itemLabel="#{c.facCode}" itemValue="#{c.id}"/></h:selectOneMenu>
ActionBean :
private List<FacilityEBean> svaFaciltyList=null;
public List<FacilityEBean> getSvaFaciltyList() {
svaFaciltyList = facilityBusServ.getFacilityListBySVAId(session.getLoginUser());
return svaFaciltyList;
}
public List<FacilityEBean> svaValueChangeEvent(){
if(svaFaciltyList!=null){
svaFaciltyList.clear();
svaFaciltyList=null;
}
svaFaciltyList = facilityBusServ.getFacilityList(Integer.parseInt(serviceAreaId));
return svaFaciltyList;
}
Your code logic flow is wrong. You seem to expect that input components are in some way directly bound to properties and that the ajax action listener methods can return (changed) property values. This is thus actually not true.
For example, the EL expression #{BoardAction.serviceAreaList} actually invokes the getter method for the property. In your particular case, the getter method fills the list with the results from the DB everytime. So whatever you're setting in the ajax listener method is overridden everytime by the business logic in the getter method.
Those getter methods should not contain business logic at all. You need to rewrite your code as follows:
private List<FacilityEBean> svaFaciltyList;
#PostConstruct
public void init() {
svaFaciltyList = facilityBusServ.getFacilityListBySVAId(session.getLoginUser());
}
public void svaValueChangeEvent() {
svaFaciltyList = facilityBusServ.getFacilityList(Integer.parseInt(serviceAreaId));
}
public List<FacilityEBean> getSvaFaciltyList() {
return svaFaciltyList;
}
I want to genrate a unique number in <p:inputText> on page load.
I can generate an unique value using java.util.UUID, but how can I set it on the value of the <p:inputText> on page load?
<p:inputText id="ptId" label="PatientId" value="#{addBB.pt.patientId}" />
Just set the value during bean's (post)construction.
#ManagedBean
#ViewScoped
public class AddBB {
private Patient pt;
#PostConstruct
public void init() {
pt = new Patient();
pt.setPatientId(UUID.randomUUID().toString());
}
// ...
}
you can do this just by making userId, the default value for inputText like this -
value="#{beanName.userId}"
so that first use it like u want to use and then u can set the value of userId at any point of time as the unique id, just remember to reRender it.
Hope you got what u wanted....
I have a f:convertDateTime with a pattern of mm/dd/yyyy. However, people are able to enter 2/19/78 and it would be 0078 rather then 1978 or 2078. I want to force people to enter in all 4 digits.
I tried using a regexPattern validator, but that is complaining because it wants a string and not a Date object. Seems that the converters fire first and validators validate the converted value?
I guess I could write a custom converter or validator, but this seems like such a simple thing I figure I'm doing something wrong.
The javadocs for the convertor say it is strict in matching the pattern, but I'm not seeing that?
Any ideas or suggestions?
thanks!
It's only strict for days/months, not for years. Here's an extract of relevance from SimpleDateFormat javadoc which <f:convertDateTime> is using under the covers:
For parsing, if the number of pattern letters is more than 2, the year is interpreted literally, regardless of the number of digits. So using the pattern "MM/dd/yyyy", "01/11/12" parses to Jan 11, 12 A.D.
It's by design indeed not possible to fire validators before converters. Essentially, this one should have thrown a ConverterException because the input is not in the proper format. I'd create a custom converter which validates the pattern beforehand. Something like this:
#FacesConverter("validatingPatternDateTimeConverter")
public class ValidatingPatternDateTimeConverter extends DateTimeConverter {
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
String regex = getMandatoryAttribute(component, "validateRegex");
String pattern = getMandatoryAttribute(component, "convertPattern");
if (value != null && !value.matches(regex)) {
throw new ConverterException(new FacesMessage(String.format("Invalid date, must be in pattern %s", pattern)));
}
setPattern(pattern);
return super.getAsObject(context, component, value);
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
setPattern(getMandatoryAttribute(component, "convertPattern"));
return super.getAsString(context, component, value);
}
private String getMandatoryAttribute(UIComponent component, String name) {
String value = (String) component.getAttributes().get(name);
if (value == null || value.isEmpty()) {
throw new IllegalArgumentException(String.format("<f:attribute name=\"%s\"> is missing.", name));
}
return value;
}
}
which is to be used as follows:
<h:inputText value="#{bean.date}">
<f:converter converterId="validatingPatternDateTimeConverter" />
<f:attribute name="validateRegex" value="\d{1,2}/\d{1,2}/\d{4}" />
<f:attribute name="convertPattern" value="MM/dd/yyyy" />
</h:inputText>