What is the correct way to use RequestScoped Bean and rendered attribute? - jsf

does anybody know how to use RequestScoped bean together with rendered attribute in jsf? The rendered attribute is evaluated before applyValues phase and therefore is not correctly evaluated. I don't want to preserve any state. The example could be an outputPanel with a datatable and a button. The datatable gets a list of values. The wrapping outputPanel has the rendered attribute like:
<p:outputPanel rendered="#{not empty requestScopedBean.dataList}">
<p:datatable value="#{requestScopedBean.dataList}">
...
</p:datatable>
<p:commandButton action="#{requestScopedBean.someAction}" />
</p:outputPanel>
After loading the page and clicking on the button, nothing happens, because the view is restored and expressions are evaluated - the bean does have an empty datalist and therefore the panel should not be rendered. This causes that the action method is not even called - because the button doesn't exist.

If you're not interested in having a filled data table at that moment, just add an extra check in rendered attribute if the command button of interest has been invoked. You can do that by checking the presence of button's client ID in request parameter map.
<p:outputPanel rendered="#{not empty requestScopedBean.dataList or not empty param[someButton.clientId]}">
...
<p:commandButton binding="#{someButton}" ... />
</p:outputPanel>
See also:
How to let validation depend on the pressed button?

Related

Update primefaces parent component, without re-render its datatable child

I want to update the parent component (an outputpanel) of a datatable without the datatable itself (lazy loaded) so that its#load method will not get triggered (it performs a very heavy API request so I do not want it to be called for no reason).
So far I have tried to use the :not() operator from the update event but when I do so, the parent component does not update itself too, why that strange behaviour? Code example below:
Parent component I want to be updated apart from its datatable child
<h:form id="myForm">
<p:outputPanel id="parentContainer" styleClass="fullHeight parent"
style="display:#{(myBean.showCreateForm == false)?'block;':'none'}">
<p:dataTable id="myDatatable" lazy="true"
styleClass="exclude" ...
</p:dataTable>
</p:outputPanel>
</h:form>
Button updating the upper form
// this button toggles the myBean.showCreateForm variable show it toggles the upper div
<p:commandButton update="#(.parent :not(.exclude))" partialSubmit="true" ajax="true">
The behaviour I would like to have from the code above is:
1)On click of the button I want to toggle the parentContainer div but 2)do not re-render its datatable through the ajax update and call its #load method (since it is lazy loaded).
Unfortunately when I exclude the datatable through the :not selector, the parent element (parentContainer) does not also update/toggles.
Is there any way to achieve my case?

Cannot call action methods on RequestScoped Bean from tabView [duplicate]

does anybody know how to use RequestScoped bean together with rendered attribute in jsf? The rendered attribute is evaluated before applyValues phase and therefore is not correctly evaluated. I don't want to preserve any state. The example could be an outputPanel with a datatable and a button. The datatable gets a list of values. The wrapping outputPanel has the rendered attribute like:
<p:outputPanel rendered="#{not empty requestScopedBean.dataList}">
<p:datatable value="#{requestScopedBean.dataList}">
...
</p:datatable>
<p:commandButton action="#{requestScopedBean.someAction}" />
</p:outputPanel>
After loading the page and clicking on the button, nothing happens, because the view is restored and expressions are evaluated - the bean does have an empty datalist and therefore the panel should not be rendered. This causes that the action method is not even called - because the button doesn't exist.
If you're not interested in having a filled data table at that moment, just add an extra check in rendered attribute if the command button of interest has been invoked. You can do that by checking the presence of button's client ID in request parameter map.
<p:outputPanel rendered="#{not empty requestScopedBean.dataList or not empty param[someButton.clientId]}">
...
<p:commandButton binding="#{someButton}" ... />
</p:outputPanel>
See also:
How to let validation depend on the pressed button?

Is there a way how to trigger an event / make a commandbutton hide when selectCheckboxMenu in primefaces unselected all items

i wanted to know if theres a way how to hide a commandbutton to the end users when he deselects all items in the selectCheckboxMenu.
thanks for every comments and suggestions.
Just let the rendered attribute of the command button check if the very same property behind the value attribute of select checkbox menu does not represent an empty collection. You can re-execute this check by updating a persistent parent component of the button using <p:ajax> on change of the select checkbox menu.
So, in a nutshell:
<p:selectCheckboxMenu value="#{bean.selectedItems}">
<f:selectItems value="#{bean.availableItems}" />
<p:ajax update="button" />
</p:selectCheckboxMenu>
<h:panelGroup id="button">
<p:commandButton value="Submit" rendered="#{not empty bean.selectedItems}" />
</h:panelGroup>
No need for unnecessary code such as additional bean properties or listener methods specifically for value change and rendered attribute or ugly hacks such as valueChangeListener as mentioned by the other answer whose answerer is apparently having JSF 1.x in mind.
For command button set rendered attribute for ex
In managed bean create a boolean variable allCheckBoxNotSelected with getters and setters
For checkboxes in valueChangeListener attribute call a managed bean method which will check current values for all check box. If it is not selected then put false to allCheckBoxNotSelected variable and then upadate command button through its id.

render richfaces popupPanel after bean method is finished

I have a simple problem where I want to display a popup if something went wrong in my managed bean.
The bean holds a list of exceptions that can be raised, with getter/setter methods.
The xhtml looks like this
<rich:panel>
<h:form>
<a4j:commandButton value="Compute Mission"
action="#{missionHandler.generateMissionFeasability}"
render="popupPanel">
</a4j:commandButton>
</h:form>
</rich:panel>
<rich:popupPanel id="popupPanel" modal="true" autosized="true"
resizeable="false" moveable="false" rendered="#{not empty missionHandler.exceptions}">
<f:facet name="header">
<h:outputText value="Exceptions raised during the processing " />
</f:facet>
<f:facet name="controls">
<h:outputLink value="#"
onclick="#{rich:component('popupPanel')}.hide();return false;">
</h:outputLink>
</f:facet>
</rich:popupPanel>
As you see I have a command button that should call generateMissionFeasibility method in the bean.
The method will (among other things) add exception in the exceptions list.
I would like to check the list (if it's empty or not) to display the popup
The code above doesn't work because I think the popup is rendered before the end of the method in the bean, and the list is empty at the beginning.
One way to make popup panel be shown once rendered is to change
rendered="#{not empty missionHandler.exceptions}"
to
show="#{not empty missionHandler.exceptions}"
The code doesn't work because the first time the view is about to be rendered, missionHandler.exceptions will be empty, which means popupPanel never makes it to the browser. Subsequent requests to reRender popupPanel will fail as the component is nowhere to be found in the DOM.
For a component to be ajax-updated, it must already be in the DOM in the browser, this is the way ajax works. So the solution is to wrap the content of the popup panel in a component that will always be rendered.
That aside, even if you got the rendering correct, your popup will only be placed in the DOM. You actually need to call show() on the popup to get it to showup
To achieve what you want however, a better alternative will be to
Conditionally display the popup using javascript. If the condition is met, the show() function is called for the popup. Otherwise, an empty, do-nothing javascript function will be called.
<a4j:commandButton value="Compute Mission" action="#missionHandler.generateMissionFeasability}"
oncomplete="#{not empty missionHandler.exceptions ? #{rich:component('popupPanel')}.show()" : doNothing()}" render="popupPanel">
</a4j:commandButton>
For the doNothing js:
<script> function doNothing(){} <script/>
Take the rendering condition out of the modal panel
EDIT: Additionally, the show attribute on the popup component can be based on the same EL condition as the oncomplete attribute

Primefaces commandButton action attribute not being called

I am creating a JSF application with primefaces. Basically I have this view. There is a tab view which for each tab contains a command button and a accordion panel (another kind of tab view). The tabs of the accordion panel among other elements, contain each one command button. My problem is that the first command button (under 1 level of tabs) calls correctly the action method when it is clicked, while the second button (under 2 level of tabs) does not. I should say that both the tabView and accordionPanel are working correctly, since they are displaying the information they should display.
I am posting a simplified version of my view so that you can see what is happening.
<h:form>
<p:tabView id="unitTabs" orientation="left" dynamic="true" cache="false" var="unit" value="#{unitController.getUnitsOfLoggedInUser(loginController.checkedUser)}">
<p:tab id="unitTab" title="#{unit.unitName}">
<p:commandButton value="Add Lecture" action="#{unitController.setTemporary(unit)}" onclick="createLectureDialog.show()">
<p:accordionPanel id="lectureTabs" value ="#{lectureController.getLecturesForUnit(unit)}" var="lecture" dynamic="true" cache="false">
<p:tab title="#{lecture.lectureName}">
<p:commandButton value="Add Criterion" action ="#{lectureController.setTemporary(lecture)}" onclick="createCriterionDialog.show()" >
</p:tab>
</p:accordionPanel>
</p:tab>
</p:tabView>
</h:form>
What am i doing wrong? Thanks
This construct requires that the EL expression in the value attribute of the <p:tabView> and <p:accordionPanel> returns exactly the same value during processing the form submit as it was during the initial display.
If the bean is request scoped and/or the value depends behind the scenes on a request based parameter or variable and it thus returns a different value on every request, then it will fail because JSF cannot locate the button which was been invoked. To fix it, the bean needs to be placed in the view scope and the getter method should not contain any business logic, or any request based parameters or variables should be retained in the subsequent requests.
See also:
commandButton/commandLink/ajax action/listener method not invoked or input value not updated - point 4.

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