JSF rerender data loaded from DB

Question

I have data loaded from DB, when click a command button:

<h:commandButton value="Show article content and comments" action="#{dataBean.activateArticleContentView}" actionListener="#{dataBean.loadCurrentArticle}">
<f:attribute name="articleId" value="#{article.id}"></f:attribute>
</h:commandButton>

@ManagedBean
@ViewScoped
public class DataBean implements Serializable {

    ...

    private List<UserAcc> users;
    private List<Article> articles;
    private List<ArticleComment> articleComments;

    private Article currentArticle;

    public void loadComments(ActionEvent e) {
        DataBaseUtil dbu = new DataBaseUtil();
        int articleId = (Integer) e.getComponent().getAttributes()
                .get("articleId");
        articleComments = dbu.loadArticleComments(articleId);
    }

    public void loadCurrentArticle(ActionEvent e) {
        DataBaseUtil dbu = new DataBaseUtil();
        int articleId = (Integer) e.getComponent().getAttributes()
                .get("articleId");
        this.currentArticle = dbu.loadArticleById(articleId);
        this.currentArticle.setComments(dbu.loadArticleComments(articleId));
    }
...

it loads the article and it's comments. Also textArea and a commandButton are rendered, on the same page, for adding a comment.

<h:inputTextarea value="#{persistenceBean.text}" style="height: 50px; width: 300px">
</h:inputTextarea>
<h:commandButton value="Save" actionListener="#{persistenceBean.saveComment}">
    <f:attribute name="userName" value="#{loginBean.name}"></f:attribute>
    <f:attribute name="articleId" value="#{dataBean.currentArticle.id}"></f:attribute>
</h:commandButton>

The command button activates this method in another bean (PersistenceBean):

public void saveComment(ActionEvent e){
        int articleId = (Integer) e.getComponent().getAttributes().get("articleId");
        String userName = (String) e.getComponent().getAttributes().get("userName");

        DataBaseUtil dbu = new DataBaseUtil();

        UserAcc user = dbu.loadUserByName(userName);
        ArticleComment comment = new ArticleComment();
        comment.setText(this.text);
        Date postat = new Date();
        comment.setPostat(postat.toString());

        dbu.saveComment(articleId, user.getId(), comment);
    }

My question is how to rerender the table with the comments, so that the change can be shown immediately. Now i need to back to the articles view and click the button that shows the article content and comments. Can i have more than one action listener for the button that adds the comment, int other words, how to use dataBean.loadCurrentArticle once again after add the comment.

score 0 · Accepted Answer · edited May 23 '17 at 12:04

Change

actionListener="#{persistenceBean.saveComment}"

to

actionListener="#{dataBean.saveComment}"

and inject PersistenceBean in DataBean (by @EJB, I assume?) so that you can do as follows in DataBean#saveComment():

persistenceBean.saveComment(e);
loadCurrentArticle();

Unrelated to the concrete problem, there are way more elegant ways to pass attributes in JSF 2.x. See also How can I pass selected row to commandLink inside dataTable?

JSF rerender data loaded from DB

1 Answers1