I'm using PrimeFaces SelectOneMenu as follows:
<p:selectOneMenu id="inviteAbleRoleSelect"
styleClass="dropDownSelector"
value="#{invitationManagedBean.selectedRole}">
<f:selectItems value="#{invitationManagedBean.inviteAbleRoles}"
var="role"
itemValue="#{role}"
itemLabel="#{localized[role.concat('RoleName')]}">
</f:selectItems>
</p:selectOneMenu>
And the following JavaScript called on complete:
function handleUserInvitationRequest(xhr,status,args){
if (args.validationFailed) {
jQuery('#userInviterDialog').effect("shake", {
times : 3
}, 70);
} else {
userInviterDialogVar.hide();
refreshInvitedUserList();
}
}
When I submit the form, I get an ajax POST with the correctly filled form, but when it calls the handler, the validationFailed is true, even if the element is not required. Also the changes coming in the ajax response sets the select to an empty select.
Any idea?
It was a totally lame fault...
The bean was #RequestScoped ...
At least #ViewScoped is required.
If your role is not a String or any primitive type, then you are probably getting Validation Error: Value is not valid, therefor you need to implement a Converter for your Role Entity/Object, it would be something like this.
#FacesConverter("roleConverter")
public class RoleConverter implements Converter {
#Override
public Object getAsObject(FacesContext context,
UIComponent component,
String value) {
//prepare your datasource ex. EJB .. etc
if (value.trim().equals("")) {
return null;
} else {
Role role = datasource.findById(value); //get role from database
retun role;
}
}
#Override
public String getAsString(FacesContext context,
UIComponent component,
Object value) {
if (value == null || value.equals("")) {
return "";
} else {
return String.valueOf(((Role) value).getId());
}
}
}
selectOneMenu
<p:selectOneMenu id="inviteAbleRoleSelect"
styleClass="dropDownSelector"
value="#{invitationManagedBean.selectedRole}" converter="roleConverter">
<f:selectItems value="#{invitationManagedBean.inviteAbleRoles}"
var="role"
itemValue="#{role}"
itemLabel="#{localized[role.concat('RoleName')]}">
</f:selectItems>
</p:selectOneMenu>
And you need to make sure that your Role implements equals and hashcode.
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.
I am having trouble to find my fault when recieving the Error "Validation Error: Value is not valid". After submitting a form, im getting this error, even though, when debugging, the selected Component is the right one. The converter seems to be working fine too thats why I am having a really tough time here. Here is what I have tried so far:
Change #RequestScoped to #ManagedBean and #ViewScoped - Made the SelectOneMenue beofore crash everytime because of a NullpointerException, this did never happen with #RequestScoped, so I am not sure what is happening there...
I double checked the Converter for this SelectedOneMenue, it seems to be working, I made a lot of debugging there, the Object that was converted to a String is, at least visible for me, the same that is later converted back from String to the Object.
The equals() Method: The equals Method seems OK to me, it literally just checks if the .id is the same, when checking this at the converter, it is always right. Maybe I'd rather search here for the error, even though I cant figure out what could be possibly wrong here.
Here are the parts of my code that I guess will be interesting for you, I have already made quite some research, I found quite good stuff though I couldn't get this to work but this must not mean anything since I just started programming with JavaEE and JSF ( + Primefaces).
Component equals() Method
#Override
public boolean equals(Object obj) {
if(obj == null){
//System.out.println("Component is NULL in equals() method");
}
if(this.id == ((Component) obj).id) {
return true;
}else {
return false;
}
}
Component Converter Class
#ManagedBean(name = "componentConverterBean")
#FacesConverter (value = "componentConverter")
public class ComponentConverter implements Converter{
#PersistenceContext(unitName="PU")
private EntityManager em;
#Override
public String getAsString(FacesContext context, UIComponent component, Object modelValue) {
if (modelValue == null) {
return "";
}
return modelValue.toString();
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String submittedValue) {
if (submittedValue == null || submittedValue.isEmpty()) {
System.out.println("ComponentConverter: submittedValue is null");
return null;
}
try {
System.out.println("ComponentConverter: Value to be found: " + submittedValue);
return em.find(Component.class, Integer.parseInt(submittedValue));
} catch (NumberFormatException e) {
throw new ConverterException(new FacesMessage(submittedValue + " is not a valid Component ID", e.getMessage()));
}
}
}
Part of the .xhtml file containing the SelectOneMenues
<p:outputLabel for="facility" value="Facility: " />
<p:selectOneMenu id="facility" value="#{visualization.facility}" converter="#{facilityConverterBean}" style="width:150px">
<p:ajax process="#this" partialSubmit="true" listener="#{visualization.onFacilityChange()}" update="component" />
<f:selectItem itemLabel="Select Facility" noSelectionOption="true" />
<f:selectItems value="#{visualization.facilities}" var="facility" itemLabel="#{facility.name}" itemValue="#{facility}" />
</p:selectOneMenu>
<p:outputLabel for="component" value="Components: " />
<p:selectOneMenu id="component" value="#{visualization.component}" converter="#{componentConverterBean}" style="width:150px">
<f:selectItem itemLabel="Select Component" noSelectionOption="true" />
<f:selectItems value="#{visualization.components}" var="comp" itemLabel="#{comp.name}" itemValue="#{comp}" />
</p:selectOneMenu>
"Components: Überprüfungsfehler: Wert ist ungültig."
This is the exact Error, which translates to:
"Components: Validation error: Value is not valid. "
I am very grateful for any help here. Thanks in advance.
Use a container object instead of an entity for value="#{visualization.component}".
e.g.
class ComponentDto {
private Component componentEntity;
private Component getComponentEntity() {
return this.componentEntity;
}
private void setComponentEntity(Component componentEntity) {
this.componentEntity = componentEntity;
}
}
See also: https://github.com/primefaces/primefaces/issues/2756
I'm populating a <p:selectOneMenu/> from database as follows.
<p:selectOneMenu id="cmbCountry"
value="#{bean.country}"
required="true"
converter="#{countryConverter}">
<f:selectItem itemLabel="Select" itemValue="#{null}"/>
<f:selectItems var="country"
value="#{bean.countries}"
itemLabel="#{country.countryName}"
itemValue="#{country}"/>
<p:ajax update="anotherMenu" listener=/>
</p:selectOneMenu>
<p:message for="cmbCountry"/>
The default selected option, when this page is loaded is,
<f:selectItem itemLabel="Select" itemValue="#{null}"/>
The converter:
#ManagedBean
#ApplicationScoped
public final class CountryConverter implements Converter {
#EJB
private final Service service = null;
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
try {
//Returns the item label of <f:selectItem>
System.out.println("value = " + value);
if (!StringUtils.isNotBlank(value)) {
return null;
} // Makes no difference, if removed.
long parsedValue = Long.parseLong(value);
if (parsedValue <= 0) {
throw new ConverterException(new FacesMessage(FacesMessage.SEVERITY_ERROR, "", "Message"));
}
Country entity = service.findCountryById(parsedValue);
if (entity == null) {
throw new ConverterException(new FacesMessage(FacesMessage.SEVERITY_WARN, "", "Message"));
}
return entity;
} catch (NumberFormatException e) {
throw new ConverterException(new FacesMessage(FacesMessage.SEVERITY_ERROR, "", "Message"), e);
}
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
return value instanceof Country ? ((Country) value).getCountryId().toString() : null;
}
}
When the first item from the menu represented by <f:selectItem> is selected and the form is submitted then, the value obtained in the getAsObject() method is Select which is the label of <f:selectItem> - the first item in the list which is intuitively not expected at all.
When the itemValue attribute of <f:selectItem> is set to an empty string then, it throws java.lang.NumberFormatException: For input string: "" in the getAsObject() method even though the exception is precisely caught and registered for ConverterException.
This somehow seems to work, when the return statement of the getAsString() is changed from
return value instanceof Country?((Country)value).getCountryId().toString():null;
to
return value instanceof Country?((Country)value).getCountryId().toString():"";
null is replaced by an empty string but returning an empty string when the object in question is null, in turn incurs another problem as demonstrated here.
How to make such converters work properly?
Also tried with org.omnifaces.converter.SelectItemsConverter but it made no difference.
When the select item value is null, then JSF won't render <option value>, but only <option>. As consequence, browsers will submit the option's label instead. This is clearly specified in HTML specification (emphasis mine):
value = cdata [CS]
This attribute specifies the initial value of the control. If this attribute is not set, the initial value is set to the contents of the OPTION element.
You can also confirm this by looking at HTTP traffic monitor. You should see the option label being submitted.
You need to set the select item value to an empty string instead. JSF will then render a <option value="">. If you're using a converter, then you should actually be returning an empty string "" from the converter when the value is null. This is also clearly specified in Converter#getAsString() javadoc (emphasis mine):
getAsString
...
Returns: a zero-length String if value is null, otherwise the result of the conversion
So if you use <f:selectItem itemValue="#{null}"> in combination with such a converter, then a <option value=""> will be rendered and the browser will submit just an empty string instead of the option label.
As to dealing with the empty string submitted value (or null), you should actually let your converter delegate this responsibility to the required="true" attribute. So, when the incoming value is null or an empty string, then you should return null immediately. Basically your entity converter should be implemented like follows:
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
if (value == null) {
return ""; // Required by spec.
}
if (!(value instanceof SomeEntity)) {
throw new ConverterException("Value is not a valid instance of SomeEntity.");
}
Long id = ((SomeEntity) value).getId();
return (id != null) ? id.toString() : "";
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
if (value == null || value.isEmpty()) {
return null; // Let required="true" do its job on this.
}
if (!Utils.isNumber(value)) {
throw new ConverterException("Value is not a valid ID of SomeEntity.");
}
Long id = Long.valueOf(value);
return someService.find(id);
}
As to your particular problem with this,
but returning an empty string when the object in question is null, in turn incurs another problem as demonstrated here.
As answered over there, this is a bug in Mojarra and bypassed in <o:viewParam> since OmniFaces 1.8. So if you upgrade to at least OmniFaces 1.8.3 and use its <o:viewParam> instead of <f:viewParam>, then you shouldn't be affected anymore by this bug.
The OmniFaces SelectItemsConverter should also work as good in this circumstance. It returns an empty string for null.
If you want to avoid null values for your select component, the most elegant way is to use the noSelectionOption.
When noSelectionOption="true", the converter will not even try to process the value.
Plus, when you combine that with <p:selectOneMenu required="true"> you will get a validation error, when user tries to select that option.
One final touch, you can use the itemDisabled attribute to make it clear to the user that he can't use this option.
<p:selectOneMenu id="cmbCountry"
value="#{bean.country}"
required="true"
converter="#{countryConverter}">
<f:selectItem itemLabel="Select"
noSelectionOption="true"
itemDisabled="true"/>
<f:selectItems var="country"
value="#{bean.countries}"
itemLabel="#{country.countryName}"
itemValue="#{country}"/>
<p:ajax update="anotherMenu" listener=/>
</p:selectOneMenu>
<p:message for="cmbCountry"/>
Now if you do want to be able to set a null value, you can 'cheat' the converter to return a null value, by using
<f:selectItem itemLabel="Select" itemValue="" />
More reading here, here, or here
You're mixing a few things, and it's not fully clear to me what you want to achieve, but let's try
This obviously causes the java.lang.NumberFormatException to be thrown
in its converter.
It's nothing obvious in it. You don't check in converter if value is empty or null String, and you should. In that case the converter should return null.
Why does it render Select (itemLabel) as its value and not an empty
string (itemValue)?
The select must have something selected. If you don't provide empty value, the first element from list would be selected, which is not something that you would expect.
Just fix the converter to work with empty/null strings and let the JSF react to returned null as not allowed value. The conversion is called first, then comes the validation.
I hope that answers your questions.
In addition to incompleteness, this answer was deprecated, since I was using Spring at the time of this post :
I have modified the converter's getAsString() method to return an empty string instead of returning null, when no Country object is found like (in addition to some other changes),
#Controller
#Scope("request")
public final class CountryConverter implements Converter {
#Autowired
private final transient Service service = null;
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
try {
long parsedValue = Long.parseLong(value);
if (parsedValue <= 0) {
throw new ConverterException(new FacesMessage(FacesMessage.SEVERITY_ERROR, "", "The id cannot be zero or negative."));
}
Country country = service.findCountryById(parsedValue);
if (country == null) {
throw new ConverterException(new FacesMessage(FacesMessage.SEVERITY_WARN, "", "The supplied id doesn't exist."));
}
return country;
} catch (NumberFormatException e) {
throw new ConverterException(new FacesMessage(FacesMessage.SEVERITY_ERROR, "", "Conversion error : Incorrect id."), e);
}
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
return value instanceof Country ? ((Country) value).getCountryId().toString() : ""; //<--- Returns an empty string, when no Country is found.
}
}
And <f:selectItem>'s itemValue to accept a null value as follows.
<p:selectOneMenu id="cmbCountry"
value="#{stateManagedBean.selectedItem}"
required="true">
<f:selectItem itemLabel="Select" itemValue="#{null}"/>
<f:selectItems var="country"
converter="#{countryConverter}"
value="#{stateManagedBean.selectedItems}"
itemLabel="#{country.countryName}"
itemValue="${country}"/>
</p:selectOneMenu>
<p:message for="cmbCountry"/>
This generates the following HTML.
<select id="form:cmbCountry_input" name="form:cmbCountry_input">
<option value="" selected="selected">Select</option>
<option value="56">Country1</option>
<option value="55">Country2</option>
</select>
Earlier, the generated HTML looked like,
<select id="form:cmbCountry_input" name="form:cmbCountry_input">
<option selected="selected">Select</option>
<option value="56">Country1</option>
<option value="55">Country2</option>
</select>
Notice the first <option> with no value attribute.
This works as expected bypassing the converter when the first option is selected (even though require is set to false). When itemValue is changed to other than null, then it behaves unpredictably (I don't understand this).
No other items in the list can be selected, if it is set to a non-null value and the item received in the converter is always an empty string (even though another option is selected).
Additionally, when this empty string is parsed to Long in the converter, the ConverterException which is caused after the NumberFormatException is thrown doesn't report the error in the UIViewRoot (at least this should happen). The full exception stacktrace can be seen on the server console instead.
If someone could expose some light on this, I would accept the answer, if it is given.
This is fully working to me :
<p:selectOneMenu id="cmbCountry"
value="#{bean.country}"
required="true"
converter="#{countryConverter}">
<f:selectItem itemLabel="Select"/>
<f:selectItems var="country"
value="#{bean.countries}"
itemLabel="#{country.countryName}"
itemValue="#{country}"/>
<p:ajax update="anotherMenu" listener=/>
</p:selectOneMenu>
The Converter
#Controller
#Scope("request")
public final class CountryConverter implements Converter {
#Autowired
private final transient Service service = null;
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
if (value == null || value.trim().equals("")) {
return null;
}
//....
// No change
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
return value == null ? null : value instanceof Country ? ((Country) value).getCountryId().toString() : null;
//**** Returns an empty string, when no Country is found ---> wrong should return null, don't care about the rendering.
}
}
public void limparSelecao(AjaxBehaviorEvent evt) {
Object submittedValue = ((UIInput)evt.getSource()).getSubmittedValue();
if (submittedValue != null) {
getPojo().setTipoCaixa(null);
}
}
<p:selectOneMenu id="tipo"
value="#{cadastroCaixaMonitoramento.pojo.tipoCaixa}"
immediate="true"
required="true"
valueChangeListener="#{cadastroCaixaMonitoramento.selecionarTipoCaixa}">
<f:selectItem itemLabel="Selecione" itemValue="SELECIONE" noSelectionOption="false"/>
<f:selectItems value="#{cadastroCaixaMonitoramento.tiposCaixa}"
var="tipo" itemValue="#{tipo}"
itemLabel="#{tipo.descricao}" />
<p:ajax process="tipo"
update="iten_monitorado"
event="change" listener="#{cadastroCaixaMonitoramento.limparSelecao}" />
</p:selectOneMenu>
In my view I am using StudentModelBean to store the data entered in the form. Consider this part of my form:
<h:selectManyCheckbox value="#{}">
<f:selectItem itemLabel="English" itemValue="English" />
<f:selectItem itemLabel="Hindi" itemValue="Hindi" />
<f:selectItem itemLabel="Telugu" itemValue="Telugu" />
</h:selectManyCheckbox>
My requirement is that I need to store each selected item value into the languageName property of each Languages object. At the end I need to get them in the List object. How can I achieve this?
You'd need to provide the whole Language objects as both the available items and the selected items. You also need to create a Converter which converts between the Language object and String, this is mandatory because HTML output and HTTP request parameters are one and all String.
Assuming that your Language object has two properties code and name and that you've an application scoped bean which look like this:
#ManagedBean
#ApplicationScoped
public class Data {
private List<Language> languages;
#PostConstruct
public void init() {
languages= new ArrayList<Language>();
languages.add(new Language("en", "English"));
languages.add(new Language("hi", "Hindi"));
languages.add(new Language("te", "Telugu"));
// ...
}
public List<Language> getLanguages() {
return languages;
}
}
Then you can use it as follows:
<h:selectManyCheckbox value="#{bean.selectedLanguages}" converter="languageConverter">
<f:selectItems value="#{data.languages}" var="language"
itemValue="#{language}" itemLabel="#{language.name}" />
</h:selectManyCheckbox>
with this bean
#ManagedBean
#ViewScoped
public class Bean {
private List<Language> selectedLanguages;
// ...
}
and this converter
#FacesConverter("languageConverter")
public class LanguageConverter implements Converter {
#Override
public String getAsString(FacesContext context, UIComponent component, Object object) {
return ((Language) object).getCode();
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String submittedValue) {
List<Language> languages = (List<Language>) context.getApplication().evaluateExpressionGet(context.getELContext(), "#{data.languages}", List.class);
for (Language language : languages) {
if (language.getCode().equals(submittedValue)) {
return language;
}
}
return null;
}
}
I have a backing bean containing a field creditCard which can have two string values y or n populated from the DB. I would like to display this in checkbox so that y and n gets converted to boolean.
How can I implement it? I can't use a custom converter as getAsString() returns String while rendering the response whereas I need a boolean.
The <h:selectBooleanCheckbox> component does not support a custom converter. The property has to be a boolean. Period.
Best what you can do is to do the conversion in the persistence layer or to add extra boolean getter/setter which decorates the original y/n getter/setter or to just replace the old getter/setter altogether. E.g.
private String useCreditcard; // I'd rather use a char, but ala.
public boolean isUseCreditcard() {
return "y".equals(useCreditcard);
}
public void setUseCreditcard(boolean useCreditcard) {
this.useCreditcard = useCreditcard ? "y" : "n";
}
and then use it in the <h:selectBooleanCheckbox> instead.
<h:selectBooleanCheckbox value="#{bean.useCreditcard}" />
You can use the BooleanConverter for java primitives, this parses the text to boolean in your managedbean, at here just put in your code like this in you .xhtml file
<p:selectOneMenu id="id"
value="#{yourMB.booleanproperty}"
style="width:60px" converter="javax.faces.Boolean">
<p:ajax listener="#{yourMB.anylistener}"
update="anyIDcontrol" />
<f:selectItem itemLabel="------" itemValue="#{null}"
noSelectionOption="true" />
<f:selectItem itemLabel="y" itemValue="true" />
<f:selectItem itemLabel="n" itemValue="false" />
</p:selectOneMenu>
ManagedBean:
#ManagedBean(name="yourMB")
#ViewScoped
public class YourMB implements Serializable {
private boolean booleanproperty;
public boolean isBooleanproperty() {
return booleanproperty;
}
public void setBooleanproperty(boolean booleanproperty) {
this.booleanproperty = booleanproperty;
}
}
I had the similar problem, and I agree with previous post, you should handle this issues in persistence layer.
However, there are other solutions. My problem was next: I have TINYINT column in database which represented boolean true or false (0=false, 1=true). So, I wanted to display them and handle as a boolean in my JSF application. Unfortunately, that was not quite possible or just I didn't find a proper way. But instead using checkbox, my solution was to use selectOneMeny and to convert those values to "Yes" or "No". Here is the code, so someone with similar problem could use it.
Converter:
#FacesConverter("booleanConverter")
public class BooleanConverter implements Converter{
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
short number= 0;
try {
if (value.equals("Yes")) {
number= 1;
}
} catch (Exception ex) {
FacesMessage message = new FacesMessage();
message.setSeverity(FacesMessage.SEVERITY_FATAL);
message.setSummary(MessageSelector.getMessage("error"));
message.setDetail(MessageSelector.getMessage("conversion_failed") + ex.getMessage());
throw new ConverterException(message);
}
return number;
//throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
return value.toString();
//throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
JSF Page:
<h:selectOneMenu id="selectOnePlayerSucc" value="#{vezbaTrening.izvedenaUspesno}" converter="booleanConverter">
<f:selectItems id="itemsPlayerSucc" value="#{trainingOverview.bool}" var="opt" itemValue="#{opt}" itemLabel="#{opt}"></f:selectItems>
And in my ManagedBean I created a list with possible values ("Yes" and "No")
private List<String> bool;
public List<String> getBool() {
return bool;
}
public void setBool(List<String> bool) {
this.bool = bool;
#PostConstruct
public void init () {
...
bool = new LinkedList<>();
bool.add("Yes");
bool.add("No");
}