NodeList (Flow Client 2.7.0 API)

java.lang.Object
- com.vaadin.client.flow.nodefeature.NodeFeature
- - com.vaadin.client.flow.nodefeature.NodeList

All Implemented Interfaces:

ReactiveValue
```
public class NodeList
extends NodeFeature
implements ReactiveValue
```
A state node feature that structures data as a list.
The list works as a reactive value with regards to its structure. A Computation will get a dependency on this list for any read operation that depends on the list structure, such as querying the length, iterating the list or finding the index of an item. Accessing an item by index does not create a dependency. The Computation is invalidated when items are added, removed, reordered or replaced. It is not invalidated when the contents of an item is updated since all items are expected to be either immutable or reactive values of their own.

Since:

1.0

Author:

Vaadin Ltd

Constructor Summary

Constructors
Constructor and Description

NodeList(int id, StateNode node)
Creates a new list.

Constructors
Constructor and Description
`NodeList(int id, StateNode node)` Creates a new list.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`add(int index, Object item)` Shorthand for adding the given item at the given index.
`elemental.events.EventRemover`	`addReactiveValueChangeListener(ReactiveValueChangeListener reactiveValueChangeListener)` Adds a listener that has a dependency to this value, and should be notified when this value changes.
`elemental.events.EventRemover`	`addSpliceListener(ListSpliceListener listener)` Adds a listener that will be notified when the list structure changes.
`void`	`clear()` Removes all the nodes from the list.
`elemental.json.JsonValue`	`convert(Function<Object,elemental.json.JsonValue> converter)` Convert the feature values into a `JsonValue` using provided `converter` for the values stored in the feature (i.e.
`void`	`forEach(JsCollections.ForEachCallback<Object> callback)` Iterates all values in this list.
`Object`	`get(int index)` Gets the item at the given index.
`elemental.json.JsonValue`	`getDebugJson()` Gets a JSON object representing the contents of this feature.
`boolean`	`hasBeenCleared()` Returns `true` if the list instance has been cleared at some point.
`int`	`length()` Gets the number of items in this list.
`void`	`set(int index, Object value)` Sets the value at the given index.
`void`	`splice(int index, int remove)` Removes a number of items at the given index.
`void`	`splice(int index, int remove, JsArray<?> add)` Removes and adds a number of items at the given index.

Methods inherited from class com.vaadin.client.flow.nodefeature.NodeFeature
getAsDebugJson, getId, getNode

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - NodeList
```
public NodeList(int id,
                StateNode node)
```
    Creates a new list.
    
    Parameters:
    
    id - the id of the list
    
    node - the node of the list
- Method Detail
  - length
```
public int length()
```
    Gets the number of items in this list.
    
    Returns:
    
    the number of items
  - get
```
public Object get(int index)
```
    Gets the item at the given index.
    
    Parameters:
    
    index - the index
    
    Returns:
    
    the item at the index
  - set
```
public void set(int index,
                Object value)
```
    Sets the value at the given index.
    
    Parameters:
    
    index - the index
    
    value - the value to set
  - add
```
public void add(int index,
                Object item)
```
    Shorthand for adding the given item at the given index. This method delegates to splice(int, int, JsArray) which updates the list contents and fires the appropriate event.
    
    Parameters:
    
    index - the index where the item should be added
    
    item - the new item to add
  - splice
```
public void splice(int index,
                   int remove)
```
    Removes a number of items at the given index. This causes a ListSpliceEvent to be fired.
    
    Parameters:
    
    index - the index at which do do the operation
    
    remove - the number of items to remove
  - clear
```
public void clear()
```
    Removes all the nodes from the list. This causes a ListSpliceEvent to be fired, with ListSpliceEvent.isClear() as true.
  - splice
```
public final void splice(int index,
                         int remove,
                         JsArray<?> add)
```
    Removes and adds a number of items at the given index.
    This causes a ListSpliceEvent to be fired.
    
    Parameters:
    
    index - the index at which do do the operation
    
    remove - the number of items to remove
    
    add - an array of new items to add
  - getDebugJson
```
public elemental.json.JsonValue getDebugJson()
```
    Description copied from class: NodeFeature
    
    Gets a JSON object representing the contents of this feature. Only intended for debugging purposes.
    
    Specified by:
    
    getDebugJson in class NodeFeature
    
    Returns:
    
    a JSON representation
  - convert
```
public elemental.json.JsonValue convert(Function<Object,elemental.json.JsonValue> converter)
```
    Description copied from class: NodeFeature
    
    Convert the feature values into a JsonValue using provided converter for the values stored in the feature (i.e. primitive types, StateNodes).
    
    Specified by:
    
    convert in class NodeFeature
    
    Parameters:
    
    converter - converter to convert values stored in the feature
    
    Returns:
    
    resulting converted value
  - addSpliceListener
```
public elemental.events.EventRemover addSpliceListener(ListSpliceListener listener)
```
    Adds a listener that will be notified when the list structure changes.
    
    Parameters:
    
    listener - the list change listener
    
    Returns:
    
    an event remover that can be used for removing the added listener
  - addReactiveValueChangeListener
```
public elemental.events.EventRemover addReactiveValueChangeListener(ReactiveValueChangeListener reactiveValueChangeListener)
```
    Description copied from interface: ReactiveValue
    
    Adds a listener that has a dependency to this value, and should be notified when this value changes.
    
    Specified by:
    
    addReactiveValueChangeListener in interface ReactiveValue
    
    Parameters:
    
    reactiveValueChangeListener - the listener to add
    
    Returns:
    
    an event remover that can be used for removing the added listener
  - forEach
```
public void forEach(JsCollections.ForEachCallback<Object> callback)
```
    Iterates all values in this list.
    
    Parameters:
    
    callback - the callback to invoke for each value
  - hasBeenCleared
```
public boolean hasBeenCleared()
```
    Returns true if the list instance has been cleared at some point.
    
    Returns:
    
    true if the list instance has been cleared

Class NodeList

Constructor Summary

Method Summary

Methods inherited from class com.vaadin.client.flow.nodefeature.NodeFeature

Methods inherited from class java.lang.Object

Constructor Detail

NodeList

Method Detail

length

get

set

add

splice

clear

splice

getDebugJson

convert

addSpliceListener

addReactiveValueChangeListener

forEach

hasBeenCleared