I tried simply:
public class UIDemoComponent extends UIComponentBase {
private String someVariable; // this gets always cleared, getters/setters omitted
public UIDemoComponent() {
super(); // place breakpoint here
}
#Override
public void encodeBegin(FacesContext context) throws IOException {
HtmlForm form = new HtmlForm();
form.setStyle("padding: 10px; background-color: blue;");
getChildren().add(form);
AjaxBehavior behavior = new AjaxBehavior();
behavior.setRender(Arrays.asList("#form"));
form.addClientBehavior("click", behavior);
}
}
I have registered a tag handler and succesfully inserted the component into page. However, when I click the blue form that is rendered, JSF re-creates the component (breakpoint in the constructor is caught). The effect of this is that any instance variables are lost. How is one supposed to save data into components if they always get re-created?
I tried overriding and inspecting the state staving mechanisms of StateHolder and PartialStateHolder wihout luck:
#Override
public Object saveState(FacesContext context) {
return super.saveState(context); // breakpoint
}
#Override
public void restoreState(FacesContext context, Object state) {
super.restoreState(context, state); // breakpoint
}
JSF is executing the saveState when page and components are created, but restoreState is never called. Actually, when the AJAX request is being processed, a new instamnce of UIDemoComponent is created but saveState method is called again, instead of restoreState.
How to create such a state-saving component (that retains the instance fields over AJAX requests)?
Seems like JSF is running some pre-checks on state object and not executing restoreState at all if custom fields are not entered. Only after actually inserting custom values into state object, the restoreState gets called.
For example:
#Override
public Object saveState(FacesContext context) {
Object[] rtrn = new Object[2];
rtrn[0] = super.saveState(context);
rtrn[1] = "dummy";
return rtrn;
}
After this, the restoreState gets called and property fields can be restored as wanted.
Related
I need to add a component (UIParameter) to a HtmlCommandLink component dinamically through a Phase Listener.
What I want to achieve is that every element <h:link outcome="out"> renders as <a href="out_url_parsed + ?param=paramvalue">.Where "param" is my component.
I've tried using this
private void addElement(final PhaseEvent event, final Class clazz, final UIComponent component) {
final FacesContext fcontext = event.getFacesContext();
UIViewRoot root = fcontext.getViewRoot();
if (root == null) {
return;
}
root.visitTree(new FullVisitContext(fcontext), new VisitCallback() {
#Override
public VisitResult visit(VisitContext context, UIComponent target) {
if (clazz.isInstance(target)) {
LOGGER.info("Element Found");
UIParameter parameter = new UIParameter();
parameter.setValue("willberonadom");
parameter.setId("sessiontoken");
target.getChildren().add(parameter);
}
return VisitResult.ACCEPT;
}
});
}
But it's not working. The element is actually found on the tree but the UIParameter does not render.
I've found that the UIViewRoot only has child elements after RENDER_RESPONSE phase. So i think this is why my added element is not rendered at the end of the process.
I'm sure I can add this param editing the views but I don't want to do that since it must be present on all h:link in the application and must be present on any other new added too. So I consider this as a better approach to avoid missing tags
On a similar case I've managed to add input hidden elements to every form on view with this code...
HtmlInputHidden hiddenToken = new HtmlInputHidden();
hiddenToken.setId("sessiontoken");
hiddenToken.setValue("willberandom");
hiddenToken.setRendered(true);
root.addComponentResource(event.getFacesContext(), hiddenToken,"form");
But it doesn't work on anchor tags
There are several mistakes:
You want to add a parameter to a HtmlCommandLink component which represents <h:commandLink>, but you're giving an example with <h:link>, which is represented by HtmlOutcomeTargetLink. What exactly do you want?
A PhaseListener on beforePhase() of RENDER_RESPONSE may be too late on GET requests which would only build the view for the first time during render response. At the moment your PhaseListener runs, the UIViewRoot would have no children at all. You'd better hook on view build time instead. For that, a SystemEventListener on PostAddToViewEvent is the best suitable.
You're setting the parameter name as an id instead of name. Use UIParameter#setName() instead of UIParameter#setId().
Provided that you actually meant to add them to <h:link> components, then here's a kickoff example how you can achieve that with a SystemEventListener.
public class YourSystemEventListener implements SystemEventListener {
#Override
public boolean isListenerForSource(Object source) {
return source instanceof HtmlOutcomeTargetLink;
}
#Override
public void processEvent(SystemEvent event) throws AbortProcessingException {
UIParameter parameter = new UIParameter();
parameter.setName("sessiontoken");
parameter.setValue("willberonadom");
((UIComponent) event.getSource()).getChildren().add(parameter);
}
}
(if you actually want to apply them on <h:commandLink> as well, just extend the isListenerForSource() check with a || source instanceof HtmlCommandLink)
In order to get it to run, register it as follows in faces-config.xml:
<application>
<system-event-listener>
<system-event-listener-class>com.example.YourSystemEventListener</system-event-listener-class>
<system-event-class>javax.faces.event.PostAddToViewEvent</system-event-class>
</system-event-listener>
</application>
I'm trying to develop a custom component that will need to call a method from the backingbean to get some data from the bb (this will be called in the decode phase after a certain Ajax call) with one parameter (it will come in the ajax call).
The problem I'm having is that I define the attribute as a MethodExpression (in the taglibrary and the component), I get the Ajax post, decode the parameter and when I try to get the Method binding from the component I get the following error:
javax.el.PropertyNotFoundException: /easyFaces.xhtml #19,151
dataSource="#{theBean.loadDataFromSource}": The class
'ar.com.easytech.faces.test.homeBean' does not have the property
'loadDataFromBean'.
Here is the relevant code.. (and please let me know if this is not the correct way to do this..)
taglib:
<attribute>
<display-name>Data Source</display-name>
<name>dataSource</name>
<required>true</required>
<type>javax.el.MethodExpression</type>
<method-signature>java.util.List theDataSource(java.lang.String)</method-signature>
</attribute>
Component definition:
public class Autocomplete extends HtmlInputText implements ClientBehaviorHolder
...
public MethodExpression getDataSource() {
return (MethodExpression) getStateHelper().eval(PropertyKeys.dataSource);
}
public void setDataSource(MethodExpression dataSource) {
getStateHelper().put(PropertyKeys.dataSource, dataSource);
}
and finally the rendered method that generates the error:
private List<Object> getData(FacesContext context, Autocomplete autocomplete, String data) {
Object dataObject = null;
MethodExpression dataSource = autocomplete.getDataSource();
if (dataSource != null) {
try {
dataObject = dataSource.invoke(context.getELContext(), new Object[] {data});
return convertToList(dataObject);
} catch (MethodNotFoundException e) {
logger.log(Level.INFO,"Method not found: {0}", dataSource.getExpressionString() );
}
}
return null;
}
Here is the method from the BB
public List<String> autcompleteFromSource(String param) {
List<String> tmpData = new ArrayList<String>();
tmpData.add("XXA_TABLE_A");
tmpData.add("XXA_TABLE_B");
tmpData.add("XXA_TABLE_C");
return tmpData;
}
And the .xhtml with the component
<et:autocomplete id="autoc" minLength="3" delay="500" value="#{easyfacesBean.selectedValue}" dataSource="#{easyfacesBean.autcompleteFromSource}" />
The thing is if I define a method getAutocompleteFromSource() it recognised the method and the error changes to can't convert list to MethodExpression, so evidently it is simply interpreting the autocompleteFromSource as a simple property and not a method definition, is this even the correct way to call method from BB? (giving that it's not an actual action nor validation )
I found the solution for this, as it turns out you also need to define a "Handler"to define the Method Signature, so I created the handler and added to the taglib and everything started to work fine..just for reference.. here is the handler..
Regards
public class AutocompleteHandler extends ComponentHandler {
public AutocompleteHandler(ComponentConfig config) {
super(config);
}
protected MetaRuleset createMetaRuleset(Class type) {
MetaRuleset metaRuleset = super.createMetaRuleset(type);
metaRuleset.addRule(new MethodRule("dataSource", List.class, new Class[] { String.class }));
return metaRuleset;
}
}
I have a "new item" form that requires a list of dates, with the following components:
A <rich:calendar> input;
A <a4j:commandButton> that adds the chosen date to a List<Date> chosenDates in the backing bean;
A <rich:dataTable> with it's value set to the List<Date> chosenDates attribute;
A <a4j:commandButton> per dataTable row that removes it's date from theList<Date> chosenDates;
How to validate (JSF's validation phase) the size of the chosenDates list on form submit (creation process)?
RichFaces 4, JSF 2.1 (Mojarra).
I'd advise a cleaner approach with a JSF PhaseListener. The JSF processing will stop skip ahead the other phases if validation fails. Create a PhaseListener that will inspect the size of your list during the validations phase as against during the model update/invoke action phase. Try something like this
Create a phase listener for the validations phase
public class TestPhaseListener implements PhaseListener {
#Override
public void afterPhase(PhaseEvent event) {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public void beforePhase(PhaseEvent event) {
if(event.getPhaseId().equals(PhaseId.PROCESS_VALIDATIONS)){
FacesContext ctx = event.getFacesContext();
YourBeanClass theBeanClass = ctx.getApplication().evaluateExpressionGet(ctx, "#{someBean}", YourNeanClass.class); //obtain a reference to the backing bean containing the list
/*
inspect the size of the list here and based on that throw the exception below
*/
throw new ValidatorException(new FacesMessage("Too many dates","Too Many Dates"));
}
}
#Override
public PhaseId getPhaseId() {
throw new UnsupportedOperationException("Not supported yet.");
}
}
Register your new listener in the faces_config.xml file
<lifecycle>
<phase-listener>your.package.structure.TestPhaseListener</phase-listener>
</lifecycle>
EDIT: Based on your comment, as an alternative, you can hook into the component's lifecycle using the <f:event/> tag and the preValidate or postValidate events (depending on your preference)
A listener tag to your component
<rich:dataTable>
<f:event type="preValidate" listener="#{yourBean.listener}"/>
</rich:dataTable>
Define a listener method in your backing bean to run per your defined event. The method signature must take an argument of type ComponentSystemEvent
public void preCheck(ComponentSystemEvent evt){
//You're in your backing bean so you can do pretty much whatever you want. I'd advise you mark the request as validation failed and queue FacesMessages. Obtain a reference to FacesContext and:
facesContext.validationFailed();
}
Do something like:
#{yourBean.chosenDates.size()}
I suppose you have a getter called getChosenDates which returns the chosenDates list.
Regarding your "validation concerns":
You can create a Validate method in your bean and return list of ValidationMessages. A sample is below, one that i used in my code.
public List<ValidationMessage> validate() {
List<ValidationMessage> validations = new ArrayList<ValidationMessage>();
int curSampleSize = sampleTable.getDataModel().getRowCount();
if(getNumberOfSamples() != null) {
size += getNumberOfSamples();
} else {
validations.add(new ValidationMessage("Please enter the no of samples to continue."));
return validations;
}
return validations;
}
Then, on submit you can check if you have any ValidationMessages as follows:
List<ValidationMessage> errs = validate();
if(errs.size()>0) {
FacesValidationUtil.addFacesMessages(errs);
return null;
}
Hope this helps!
If I understand the JSF lifecycle correctly, it registers the Validators during Apply Request phase.
Does that mean I cannot call addValidator to the Component object handle I have inside my decode() method that gets called during Process Request Events phase? If so, is there any other way of dynamically adding custom Validators based on component's attribute value?
Thanks
What I hope should work is similar to..
public class ValidatorWrapper implements Validator {
private DoubleRangeValidator dbRangeValidator;
private LongRangeValidator lRangeValidator;
private String requiredValidatorType;/*An attribute to choose the type of validator*/
public ValidatorWrapper(){
dbRangeValidator = new DoubleRangeValidator(10.01, 20.99);lRangeValidator = new LongRangeValidator(10, 20);
}
#Override
public void validate(FacesContext context, UIComponent component,
Object value) throws ValidatorException {
if("LONG".equalsIgnoreCase(requiredValidatorType))
lRangeValidator.validate(context, component, value);
else if("DBL".equalsIgnoreCase(requiredValidatorType))
dbRangeValidator.validate(context, component, value);
} }
I can't figure out if it is possible to use custom events using f:event. The book by Ed Burns suggests to ad the #NamedEvent annotation to the Event class and to use:
<f:event type="com.foo.bar.myEvent" listener="#{listener} />
but the event seems never to be instantiated.
From my point of view this makes sense, since the component does not know anything about the event, e.g. when to publish, so this might be useful for custom component authors only.
On the other hand, standard components should be able to publish the the event if derived from e.g. PostAddToViewEvent. Anyway, custom events seem to be never published by standard components.
Am I missing something? Is there a convenient way to use custom events with standard components?
Here is what I wanted to do:
<h:inputText id="input">
<f:event type="foo.bar.MyCustomEvent" />
</h:inputText>
public class MyCustomEvent extends javax.faces.event.PostAddToViewEvent {
}
yes you can for this you have to override some method in jsf render or component class
public class MyComponent extends HtmlInputText or public class MyRenderer extends TextRenderer
#Override
public void decode(FacesContext context, UIComponent component) {
super.decode(context, component);
String sourceName = context.getExternalContext().getRequestParameterMap().get("javax.faces.source");
if(sourceName != null && sourceName.equals(component.getClientId())){
component.queueEvent(new MyEvent(component));
}
}
but in MyEvent class you have to override some methods
#Override
public PhaseId getPhaseId() {
return PhaseId.INVOKE_APPLICATION;
}
which will define in which face this event will process (by default it is ANY_PHASE and event trigger in same phase in which it registered)
#Override
public boolean isAppropriateListener(FacesListener listener) {
return false;
}
if you have appropiate listener it must return true
if you have appropiate listener for MyEvent then JSF will call that listener's processAction(ActionEvent event) method when it will trigger event, otherwise it will call broadcast method in component class which has to be override by developer
#Override
public void broadcast(FacesEvent event) throws AbortProcessingException {
super.broadcast(event);
if(event instanceof MyEvent){
try {
processMyEvent(event);
} catch (Exception e) {
// TODO: handle exception
}
}
}
Even you can register any event by your own by using component queueEvent(FacesEvent event) method, it will regiester event and it get the phase in which it will trigger by getPhaseId() method in MyEvent class if getPhaseId() method is not overrided by devloper then it will trigger in same phase in which it registered