How can I pass selected row to commandLink inside dataTable or ui repeat

Question

I m using Primefaces in a JSF 2 application  I have a  lt p dataTable gt   and instead of selecting rows  I want the user to be able to directly execute various actions on individual rows  For that  I have several  lt p commandLink gt s in the last column     My problem  how can I pass a row ID to the action started by the command link so that I know which row to act on  I tried using an  lt f attribute gt       lt p dataTable value    bean items   var  item  gt                 lt p column gt            lt p commandLink actionListener    bean insert   value  insert  gt                lt f attribute name  id  value    item id     gt            lt  p commandLink gt        lt  p column gt    lt  p dataTable gt       But it always yields 0 - apparently the row variable f is not available when the attribute is rendered  it works when I use a fixed value      Anyone has an alternative solution

User · Answer

In my view page    lt p dataTable      gt   lt p column gt   lt p commandLink actionListener    inquirySOController viewDetail                   process   this  update   mainform dialog content             oncomplete  dlg2 show    gt       lt h graphicImage library  images  name  view png   gt       lt f param name  trxNo  value    item map  trxNo      gt   lt  p commandLink gt   lt  p column gt   lt  p dataTable gt    backing bean   public void viewDetail ActionEvent e         String trxNo   getFacesContext   getRequestParameterMap   get  trxNo         for  DTO item   list            if  item get  trxNo   toString   equals trxNo                 System out println trxNo               setSelectedItem item               break

User · Answer

As to the cause  the  lt f attribute gt  is specific to the component itself  populated during view build time   not to the iterated row  populated during view render time   There are several ways to achieve the requirement   If your servletcontainer supports a minimum of Servlet 3 0   EL 2 2  then just pass it as an argument of action listener method of UICommand  component or AjaxBehavior tag  E g    lt h commandLink action  quot   bean insert item id   quot  value  quot insert quot    gt   In combination with   public void insert Long id                    This only requires that the datamodel is preserved for the form submit request  Best is to put the bean in the view scope by  ViewScoped  You can even pass the entire item object    lt h commandLink action  quot   bean insert item   quot  value  quot insert quot    gt   with   public void insert Item item                    On Servlet 2 5 containers  this is also possible if you supply an EL implementation which supports this  like as JBoss EL  For configuration detail  see this answer    Use  lt f param gt  in UICommand component  It adds a request parameter    lt h commandLink action  quot   bean insert  quot  value  quot insert quot  gt        lt f param name  quot id quot  value  quot   item id  quot    gt    lt  h commandLink gt   If your bean is request scoped  let JSF set it by  ManagedProperty   ManagedProperty value  quot   param id  quot    private Long id      setter  Or if your bean has a broader scope or if you want more fine grained validation conversion  use  lt f viewParam gt  on the target view  see also f viewParam vs  ManagedProperty    lt f viewParam name  quot id quot  value  quot   bean id  quot  required  quot true quot    gt   Either way  this has the advantage that the datamodel doesn t necessarily need to be preserved for the form submit  for the case that your bean is request scoped     Use  lt f setPropertyActionListener gt  in UICommand component  The advantage is that this removes the need for accessing the request parameter map when the bean has a broader scope than the request scope    lt h commandLink action  quot   bean insert  quot  value  quot insert quot  gt        lt f setPropertyActionListener target  quot   bean id  quot  value  quot   item id  quot    gt    lt  h commandLink gt   In combination with  private Long id      setter  It ll be just available by property id in action method  This only requires that the datamodel is preserved for the form submit request  Best is to put the bean in the view scope by  ViewScoped    Bind the datatable value to DataModel lt E gt  instead which in turn wraps the items    lt h dataTable value  quot   bean model  quot  var  quot item quot  gt   with  private transient DataModel lt Item gt  model    public DataModel lt Item gt  getModel          if  model    null             model   new ListDataModel lt Item gt  items               return model       making it transient and lazily instantiating it in the getter is mandatory when you re using this on a view or session scoped bean since DataModel doesn t implement Serializable  Then you ll be able to access the current row by DataModel getRowData   without passing anything around  JSF determines the row based on the request parameter name of the clicked command link button    public void insert          Item item   model getRowData         Long id   item getId                    This also requires that the datamodel is preserved for the form submit request  Best is to put the bean in the view scope by  ViewScoped    Use Application evaluateExpressionGet   to programmatically evaluate the current   item    public void insert          FacesContext context   FacesContext getCurrentInstance         Item item   context getApplication   evaluateExpressionGet context   quot   item  quot   Item class        Long id   item getId                       Which way to choose depends on the functional requirements and whether the one or the other offers more advantages for other purposes  I personally would go ahead with  1 or  when you d like to support servlet 2 5 containers as well  with  2

User · Answer

In JSF 1 2 this was done by  lt f setPropertyActionListener gt   within the command component   In JSF 2 0  EL 2 2 to be precise  thanks to BalusC  it s possible to do it like this  action    filterList insert f id

User · Answer

Thanks to this site by Mkyong  the only solution that actually worked for us to pass a parameter was this   lt h commandLink action    user editAction   gt       lt f param name  myId  value    param id     gt   lt  h commandLink gt    with  public String editAction        Map lt String String gt  params                FacesContext getExternalContext   getRequestParameterMap      String idString   params get  myId      long id   Long parseLong idString             Technically  that you cannot pass to the method itself directly  but to the JSF request parameter map

[jsf] How can I pass selected row to commandLink inside dataTable or ui:repeat?

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