> For the complete documentation index, see [llms.txt](https://hantsy.gitbook.io/java-ee-8-by-example/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hantsy.gitbook.io/java-ee-8-by-example/jsf/jsf-uidata.md).
# UIData improvements
In JSF 2.3, `` and `` support `Iterable` and `Map`.
## Iterable example
Let's create a simple demo to try it.
The backing bean.
```java
@Model
public class IterableBean {
@Inject Logger LOG;
private Iterable data = Arrays.asList("javaee 8", "jsf 2.3");
public Iterable getData() {
LOG.log(Level.INFO, "called IterableBean.getData");
return data;
}
}
```
And the facelets template.
```markup
JSF 2.3: DataModel Sample
JSF 2.3: Iterable interface Sample
h:dataTable Iterable interface
#{entry}
ui:repeat Iterable interface
Item: #{item}
```
## Map example
The backing bean.
```java
@Model
public class MapBean {
@Inject
Logger LOG;
private Map data = new HashMap<>();
public Map getData() {
LOG.log(Level.INFO, "called MapBean.getData");
data.put(1, "java ee 8");
data.put(2, "jsf 2.3");
return data;
}
}
```
And the facelets template.
```markup
JSF 2.3: DataModel Sample
JSF 2.3:Map interface Sample
UIRepeat: Map interface
Key: #{entry.key}
Value: #{entry.value}
DataTable: Map Interface
#{entry.key}
#{entry.value}
```
## Iteration without backing data
In former versions, when you want to iterate a number collection from 0 to 10, you have to use `c:forEach` which from legacy JSP taglibs.
Now the new `ui:repeat` added this feature finally.
```markup
#{i}
```
## Custom DataModel
JSF 2.3 provides a new `@FacesDataModel` to simplify the customization of your own `DataModel`.
The backing bean.
```java
@Model
public class CustomBean {
@Inject
Logger LOG;
public UserData getUserData() {
LOG.log(Level.INFO, "called CustomBean.getUserData");
List data = IntStream.of(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
.mapToObj(i -> new User("first " + i, "last " + i))
.collect(Collectors.toList());
return new UserData(data);
}
}
```
`UserData` is just a POJO which wraps a list of `User`.
```java
public class UserData {
List users = new ArrayList<>();
public UserData() {
}
public UserData(List users) {
this.users = users;
}
public List getUsers() {
return users;
}
public void setUsers(List users) {
this.users = users;
}
}
```
```java
public class User implements Serializable {
private String firstName;
private String lastName;
public User(String firstName, String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
@Override
public String toString() {
return "User{" + "firstName=" + firstName + ", lastName=" + lastName + '}';
}
}
```
The facelets template.
```markup
User : #{item}
```
We use `UserData` as `UIRepeat` backing data, it is not supported in JSF by default. Let's fill the gap via custom `@FacesDataModel` class.
```java
@FacesDataModel(forClass = UserData.class)
public class UserDataModel extends DataModel {
UserData data = null;
int index = 0;
public UserDataModel() {
this(null);
}
public UserDataModel(UserData data) {
this.data = data;
}
@Override
public boolean isRowAvailable() {
return this.index >= 0 && this.index < this.getRowCount();
}
@Override
public int getRowCount() {
return this.data != null ? this.data.getUsers().size() : 0;
}
@Override
public User getRowData() {
if (this.index >= 0 && this.index < this.getRowCount()) {
return this.data.getUsers().get(this.index);
}
return null;
}
@Override
public int getRowIndex() {
return this.index;
}
@Override
public void setRowIndex(int rowIndex) {
this.index = rowIndex;
}
@Override
public Object getWrappedData() {
return this.data;
}
@Override
public void setWrappedData(Object data) {
this.data = (UserData) data;
}
}
```
Run this application on Glassfish, open your browser and navigate to .
Grab the [source codes](https://github.com/hantsy/ee8-sandbox) from my GitHub account, and have a try.