component binging + dynamic component init

[svkap]

Hello.

I have some troubles with component binding. I am creating some dynamic components on bean initialization. I am binding HtmlPanelGrid or HtmlPanel components and I am creating dynamic components as their children. However for some reason setters of the bound compoents are not always executed. As a result these components (the panels) do not have parent and therefor the dynamicly created components are not shown. I am initializing the components on @PostConstruct init method. I noticed that most of the times (at least on PanelGrids) if I have some other component inside the jsf page then it bound ok and it has parent (on @PostConstruct they are still null but at least the result is right). I suppose I am doing sth wrong.. Can u give me advice how this is done?

[nbelaevski]

Hi Svetoslav,

JavaDoc says that setter is not called if getter returns non-null component value.

[svkap]

I knew that I have to read the JavaDoc first .  What would you advise me? In @PostConstruct method my components are null.. So should I generate the dynamic components in the setter then?

[nbelaevski]

How does page & bean code look like?

[mpickell]

Couldn't you return a new HtmlPanelGroup() instead when you otherwise would be returning null?

That would always return a component and would have no affect on your page layout (at least I think that's true with the little knowledge I have of your problem)

[svkap]

Here is a part of my code:

        private void initPanelList() { 
            // add list all link
            HtmlPanelGroup panelGroup = new HtmlPanelGroup();
            panelGroup.setLayout("block");
            panelGroup.setStyleClass("UIPortrait");
            HtmlGraphicImage image = new HtmlGraphicImage();
            image.setUrl("/img/px.gif");
            image.setStyle("width:50px;height:50px;");
            HtmlOutputLink textLink = new HtmlOutputLink();
            textLink.setValue("./test.jsf");
            HtmlOutputText textLinkTxt = new HtmlOutputText();
            textLinkTxt.setValue("List All");
            textLink.getChildren().add(textLinkTxt);
            panelGroup.getChildren().add(image);
            panelGroup.getChildren().add(textLink);
            panelist.getChildren().add(panelGroup);
         }

         public void setPanelList(HtmlPanelGroup panelList) {
            this.panelList = panelList;
            initPanelList();
         }

This is working fairly right. However there is 1 problem. The setter is executed a couple of times and on every execute I am making new queries to the database so I can build the dynamic components. In short it is not a good idea to have init method in the setter but for now I do not know where to put it. I cannot initialize new HtmlPanelGroup component because that way I am loosing the parent and if I want to find the correct parent component I have to traverse the whole component tree. My bean is @ViewScoped . I cannot use sth like that:

         public void setPanelList(HtmlPanelGroup panelList) {
            if (panelList == null) {   
                 this.panelList = panelList;
                 initPanelList();
            }   
         }

because I am using another components along with RF and they are messing with the logic. By the way I have some troubles because of the second components and I will have to go with instantiating new HtmlPanelGroups on bean initialization. However, I hope that u could give me some advice and/or best practices for dynamic component creation.

[nbelaevski]

Svetoslav,

I'd recommend to try creating components by action and use binding only to get parent component for the created components into bean.