JSF - ValueChangeListener in Datatable

Question

How to implement correctly a ValueChangeListener with UIInput Component within a Datatable, then i getting in a listener method get the row index has changed, new value and old Value

<datatable>
<column>
  <input value="item.unitPrice" valueChangeListener="#{bean.myListener}">
</column>

Changes, not necessarily generate POST to Server, Post may be generated by others events.

Any Help, Thanks.

Answer 1

Bind the datatable's value to a DataModel:

private DataModel<Item> dataModel; // +getter

public Bean() {
    this.dataModel = new ListDataModel<Item>(loadListOfItemsFromDatabase());
}

with

<h:dataTable value="#{bean.dataModel}">

This way you can access the current index (and also the current Item) in the valuechangelistener:

public void myListener(ValueChangeEvent event) {
    int index = dataModel.getRowIndex();
    Item item = dataModel.getRowData();
    Object oldValue = event.getOldValue();
    Object newValue = event.getNewValue();
    // ...
}