Pick selected line from datatable

Question

I have a dataTable with the data in front of each given one button, when I click one button dialog is opened so that I can edit this data, but I cannot take the object that was selected to pass as parameter pro method that makes the editing.

How do I get the linha(objeto) selected from the table by clicking the edit button?

I’m doing it this way:

<p:dialog header="Pausar Atividade" widgetVar="dlg3"
                modal="true" height="300" width="700">
                <p:panelGrid columns="2" cellpadding="4" style="width:100%;margin-top:20px" columnClasses="rotulo, campo">      
                    <p:outputLabel value="Motivo" />
                    <h:panelGroup>
                        <p:inputTextarea rows="5" cols="30" counter="display1"
                            maxlength="255" counterTemplate="{0} Caracteres Restantes."
                            autoResize="false" style="width:70%" value="#{tarefaBean.tarefa.comentario}" />
                        <br />
                        <h:outputText id="display1" />
                    </h:panelGroup>
                </p:panelGrid>
                <p:commandButton value="Pausar Tarefa" style="margin-left:25%;margin-top:20px;width:50%" actionListener="#{tarefaBean.pausarTarefa}" update=":msgGlobal: frmPrin"/>
</p:dialog>

The button in the datatable:

<p:column headerText="Ações" style="text-align:center">
    <p:commandButton icon="ui-icon-check" title="Finalizar"  onclick="PF('dlg4').show();" />
    <p:commandButton icon="ui-icon-pause" title="Pausar" onclick="PF('dlg3').show();" />
</p:column>

Bean method:

public void pausarTarefa(){
    try {
        tarefa.setStatus("Pausado");
        tarefa.setDataFim(new Date());

        TarefaDAO tarefaDAO = new TarefaDAO();
        tarefaDAO.editar(tarefa);   
        FacesUtil.adicionarMsgInfo("Solicitação Enviada com Sucesso");

    } catch (RuntimeException e) {
        FacesUtil.adicionarMsgErro("Erro ao Enviar Solicitação!");
        e.printStackTrace();
    }
}

Answer 1

A best practice of programming would be to leave the processing on the Bean, who is responsible for controlling the attributes on the front end. Always remember this. It is important to note that the JSF/JSP pages must have as few rules as possible to facilitate the maintenance of the code.

Let’s solve:

On your screen, use the property action in your commandButton, and change the attribute onclick for oncomplete:

    <p:column headerText="Ações" style="text-align:center">
        <p:commandButton icon="ui-icon-check" title="Finalizar" action="#{tarefaBean.setarAtributo(tarefa)}" oncomplete="PF('dlg4').show();" />
        <p:commandButton icon="ui-icon-pause" title="Pausar" action="#{tarefaBean.setarAtributo(tarefa)}" oncomplete="PF('dlg3').show();" />
    </p:column>

In your bean add:

public synchronized void setarAtributo(Tarefa tarefa) {
    this.setTarefa(tarefa);
}

Some important remarks:

1. Use actionListener only when your bean expects one Event JSF. To call business rules and pass attributes please use action, as in our case, using Methodexpression and valid EL 2.2.
2. The attribute I’m passing in the action, task, should be the same used for iteration, ie the same used in the attribute var of your datatable.
3. The attribute has been changed from onclick for oncomplete, because this causes the component to perform all the processing of its bean, referenced in the action, and only after successfully processed, will it call the js code in the oncomplete to open the dialog.

Answer 2

First: I created an objectSelected in your Bean.

According to:

<p:column >
         <p:commandButton oncomplete="PF('dlg3').show();" icon="ui-icon-search" title="View">
            <f:setPropertyActionListener value="#{objeto_que_esta_no_var_datatable}" target="#{SEUBEAN.objetoSelecionado}" />
        </p:commandButton>
</p:column>

Third: Change your method pausarTarefa()to use the objectSelected

This is the first example of Selection in the primefaces showcase, I recommend taking a look to see which is best for you, but this option will solve your problem. Follows the link.