Adding Components And There Value Bindings Programmatically
Dear Friends ,
In One of assignment I have requirement of creating JSF Components
and There Value Bindings Programmatically
on valuechange event of a SelectOneListBox I need to create some componenet and add them to a panelGrid...up to this it's okay I have already achieved this goal but my next big challenge is creating value bindings programmatically for those components...
suppose I have created a textbox component in which user has to insert some text and that text I want to store in a database ..
how to do that...?
[566 byte] By [
pra_n_dea] at [2007-11-26 15:34:42]
# 1
Here are some examples:
JSF 1.1HtmlOutputText text = new HtmlOutputText();
ValueBinding value = FacesContext.getCurrentInstance().getApplication().createValueBinding("#{myBean.text}");
text.setValueBinding("value", value);
JSF 1.2HtmlOutputText text = new HtmlOutputText();
ValueExpression value = FacesContext.getCurrentInstance().getApplication().getExpressionFactory()
.createValueExpression(FacesContext.getCurrentInstance().getELContext(), "#{myBean.text}", String.class);
text.setValueExpression("value", value);
Which renders the same as<h:outputText value="#{myBean.text}" />
# 2
tht's simplest way ..I know but suppose
my code is like this....
public void buildComponenets(int selectedId) {
ArrayList arrList = new ArrayList();
arrList = objABC.GetDocumentParameter(selectedId);
Iterator iterate = arrList.iterator();
HtmlInputTexthtmlText;
HtmlSelectBooleanCheckbox htmlSelect;
HtmlOutputLabel htmlLabel;
HtmlMessage htmlMess;
int i = 1;
ABC objABC= new ABC();
while(iterate.hasNext())
{
objABC = (ABC)iterate.next();
String compType = objABC.getControlName();
if(compType.equals("TextBox"))
{
htmlText = new HtmlInputText();
htmlLabel=new HtmlOutputLabel();
htmlMess = new HtmlMessage();
htmlLabel.setValue(objABC.getLabelName());
htmlLabel.setId("lble"+i);
htmlText.setId("txt"+i);
htmlText.setImmediate(true);
htmlMess.setId("message"+i);
htmlMess.setFor("txt"+i);
htmlText.setRequired(objABC.isValidationRequired());
if(cotrolsPan.getChildren().contains(htmlText))
{
cotrolsPan.getChildren().remove(htmlText);
}
cotrolsPan.getChildren().add(htmlLabel);
cotrolsPan.getChildren().add(htmlText);
cotrolsPan.getChildren().add(htmlMess);
}
if(compType.equals("CheckBox"))
{
htmlSelect = new HtmlSelectBooleanCheckbox();
htmlLabel=new HtmlOutputLabel();
htmlMess = new HtmlMessage();
htmlLabel.setValue(objABC.getLabelName());
htmlLabel.setId("lble"+i);
htmlLabel.setValue(objABC.getLabelName());
htmlLabel.setId("lble"+i);
htmlSelect.setId("check"+i);
htmlSelect.setImmediate(true);
htmlMess.setId("message"+i);
htmlMess.setFor("check"+i);
htmlSelect.setRequired(objABC.isValidationRequired());
if(cotrolsPan.getChildren().contains(htmlSelect))
{
cotrolsPan.getChildren().remove(htmlSelect);
}
cotrolsPan.getChildren().add(htmlLabel);
cotrolsPan.getChildren().add(htmlSelect);
cotrolsPan.getChildren().add(htmlMess);
}
i++;
}
}
now How to create value bindings for these components
# 4
ValueExpression value = FacesContext.getCurrentInstance().getApplication().getExpressionFactory()
.createValueExpression(FacesContext.getCurrentInstance().getELContext(), "#{myBean.text}", String.class);
this code needs a myBean with a property text...
that directly means for every component I have created I need property alread defined in a myBean class..
but the real fact is that I don't know how many components my code is
going to create..how to define properties for those components
Will u please go deep in to the matter?
# 9
Hi!
I'm new to jsf, i used to work with jsp and struts and i just started a project with portlet and jsf and i'm trying ti figure out how to do this
I have the same probleme... combobox with a list, the selection of one item will fire the onvaluechanged and then the bean should go in a property file to read it and add component on the page depending of the selection
I checked what you mention earlier but the part i'm missing is how to render it, because the component i just added(HtmlOutputText) is not showing up but if i debug it i can see it in the children of the viewroot.
i like snippet of code it helps ;-)
thanks,
Denis
