How to get selected row index in JSF datatable?

Question

I have a databale on index.xhtml

Answer 1

What you can do is to use the [getRowData()][1] method on the Java bean to directly get the object located on the line that hosts the button on which the user clicked.

An example of code:

public void editBook(ActionEvent evt) {
    // We get the table object
    HtmlDataTable table = getParentDatatable((UIComponent) evt.getSource());
    // We get the object on the selected line.
    Object o = table.getRowData();
    // Eventually, if you need the index of the line, simply do:
    int index = table.getRowIndex();
    // ...
}

// Method to get the HtmlDataTable.
private HtmlDataTable getParentDatatable(UIComponent compo) {
    if (compo == null) {
        return null;
    }
    if (compo instanceof HtmlDataTable) {
        return (HtmlDataTable) compo;
    }
    return getParentDataTable(compo.getParent());
}

---

Edit

The JSF code now looks like:

<h:commandButton value="Edit" actionListener="#{IndexBean.editBook}"/>

In addition, do not forget to change the signature of editBook() method, by setting a javax.faces.event.ActionEvent argument.

Answer 2

If you use EL 2.2, for example with Tomcat7 you can try

<h:commandLink action="#{IndexBean.editBook(item)}" immediate="true">

I hope to help

Answer 3

You've already bound the <h:dataTable> component to the bean. All you need to do is:

public void editBook() throws IOException{
    int index = datatableBooks.getRowIndex(); // Actually not interesting info.
    Book book = (Book) datatableBooks.getRowData(); // This is what you want.
}

The <f:param> is also not needed here. For more hints also see this article.

Update: I can reproduce your problem. This is likely a bug with @ViewScoped. When the bean is set to @RequestScoped, it works as expected. Also when you remove the component binding and obtain the component from the viewroot yourself, it works as expected. I've filed issue 1658 about this.