Can I send Ajax "update" commands to JSF components that have not been rendered due to render option previously set to false:
render="#{BackingBean.doRender}"
doRender is set to true just before "update" has been sent.
Is this the right way?
I am using PrimeFaces and one component does not show after update even doRender is set to true in the meantime.
The ajax update works by JavaScript with the JSF-generated HTML DOM tree (as the webbrowser has retrieved). If a JSF component is not rendered, then it does not appear in the HTML DOM tree at all and hence JavaScript can't find anything to update.
You need to update a parent component instead, which is always rendered.
E.g.
<h:panelGroup id="foo">
<h:someComponent rendered="#{bean.rendered}" />
</h:panelGroup>
with
<p:commandButton ... update="foo" />
Related
I am trying to toggle a page that shows a <rich:dataTable>. Before I just included the <ui:include> template and it would just show the table the whole time.
<ui:include src="../log/viewDlg.xhtml"/>
Now I want to be able to toggle it on/off on the web-page. Showing on the page with maybe a button or link. How can I achieve it?
Update 1: I am unable to get it to show up for some odd reason, Here is what I wrote so far based on feed back
View:
<a4j:commandLink value="View"
action="#{bean.showview}" render="viewPanel"/>
<h:panelGroup id="viewPanel">
<h:panelGroup id="tableRenderPanel" rendered="#{bean.showPolicyView}">
<ui:include src="../log/viewDlg.xhtml"/>
</h:panelGroup>
</h:panelGroup>
Backing bean:
private boolean showPolicyView = false;
public void showView() {
showPolicyView = !showPolicyView;
}
public boolean isShowPolicyView(){
return showPolicyView;
}
Wrap your <ui:include> inside two <h:panelGroup> elements. There's a catch here, you can't rerender a conditional component. Why's this? because when the element's rendered attribute resolves to false, it will not be considered while rendering the view so it can't be the target of an operation (in this case, related to renderization).
Jumping to the code, you'll have this:
<h:panelGroup id="wrapperPanel">
<h:panelGroup id="tableRenderPanel" rendered="#{yourBean.renderTable}">
<ui:include src="../log/viewDlg.xhtml"/>
</h:panelGroup>
</h:panelGroup>
yourBean#renderTable is a Boolean property that determines if the component will be rendered. When it evaluates to false, the component is not included in the component tree.
Toggling the view
To toggle the view, simply create a bean method that either refreshes the page
<h:commandLink action="#{yourBean.toggleTableView}"/>
or the particular panel through AJAX. To do this in JSF 1.2, rely on extensions like RichFaces to introduce AJAX, if you can. For example, should you choose RichFaces, you can use <a4j:commandLink/> and its handy render (or reRender in older versions) attribute to achieve what you could do normally with an <f:ajax/> in JSF 2
<a4j:commandLink action="#{yourBean.toggleTableView}" reRender="wrapperPannel"/>
Or, another alternative is
<a4j:commandLink action="#{yourBean.toggleTableView}">
<a4j:support event="oncomplete" reRender="wrapperPannel"/>
</a4j:commandLink>
Please note that the reRender attribute may vary depending on the structure of your page, but it should always reference the id of the wrapping panel in the end. Also, reRender was renamed to simply render in late RichFaces versions.
So, assuming you have a renderTable property (getter + setter) in yourBean, the toggleTableView must change it, in order to dinamically define if the component is to be rendered or not (renderTable = false).
Introducing RichFaces
Check this link for help in setting up RichFaces in your project.
I like the use of ui:include better than inserting h:panelBoxes like here:
<ui:fragment rendered="#{myBean.yourCondition()}">
<ui:include src="viewA.xhtml"/>
</ui:fragment>
<ui:fragment rendered="#{not myBean.yourCondition()}">
<ui:include src="viewB.xhtml"/>
</ui:fragment>
Advantage: Tag handlers do not represent components and never become a part of the component tree once the view has been built. It won't interefere with your CSS - the h:panelBox, in contrary, inserts a div or span.
... Another approach would be c:choose, which works but can cause render phases issues.
<c:choose>
<c:when test="#{myBean.yourCondition()}">
<ui:include src="viewA.xhtml"/>
</c:when>
<c:otherwise>
<ui:include src="viewB.xhtml"/>
</c:otherwise>
</c:choose>
Caution: When fiddling with tag handlers (like any c:xxx), be sure to know the difference between UI Components and Tag Handlers. Namely that UI Components and Tag Handlers are renderend in different phases. That implies that you cannot create a variable in a composite component and use it in a nested tag handler. c:choose and ui:include are both tag handlers, so normally it's not a problem. Read the link, it's a very short example and very insightful.
I have a problem with these two commandButton : Join and Leave.
I want to hide Join if I click on leave and vice-versa.
When I put ajax on false, there is no problem (but all the page is refresh and I don't find this optimal).
But when ajax attribut is on true with specific updating (cf comment in the code), the rendering is good but the new button whitch appear become inactive. If I click on it, nothing happens (well it's seems the actionListener trigger but the view is not refreshed, I have to manual refresh to see the difference)
Thanks for reading.
<h:form id="formWaitingList" rendered="#{connexion.connected}" >
<p:commandButton id="Join"
actionListener = "#{connexion.joinWaitingList()}"
rendered="#{!connexion.waiting}"
ajax="false"
<!-- ajax="true"
update="Join,Leave"-->
value="Join"/>
<p:commandButton id="Leave"
value="Leave"
ajax="false"
<!-- ajax="true"
udpate="Join,Leave"-->
rendered="#{connexion.waiting}"
actionListener ="#{connexion.leaveWaitingList()}" />
</h:form>
It seems that you're not entirely familiar with HTML/JavaScript. You know, JSF is basically a HTML/JavaScript(/CSS) code generator. Ajax updating works basically like this in JavaScript:
After sending the ajax request to JSF via XMLHttpRequest, retrieve a XML response which contains all elements which needs to be updated along with their client IDs.
For every to-be-updated element, use document.getElementById(clientId) to find it in the current HTML DOM tree.
Replace that element by new element as specified in ajax XML response.
However, if a JSF component has not generated its HTML representation because of rendered="false", then there's nothing in the HTML DOM tree which can be found and replaced. That totally explains the symptoms you're "seeing".
You basically need to wrap conditionally rendered JSF components in a component whose HTML representation is always rendered and then reference it instead in the ajax update.
For example,
<h:form>
...
<h:panelGroup id="buttons">
<p:commandButton ... update="buttons" rendered="#{condition}" />
<p:commandButton ... update="buttons" rendered="#{not condition}" />
</h:panelGroup>
</h:form>
See also:
Why do I need to nest a component with rendered="#{some}" in another component when I want to ajax-update it?
I need to open a JSF page in a new window by POST on click of a <h:commandButton>. I know I can acheive this using the JavaScript. But I would like to achive this using JSF and not JavaScript.
How can I achieve this? I'm using JSF 2.0.
The only non-JS way is to set target="_blank" in the parent <h:form>.
<h:form target="_blank">
...
<h:commandButton value="Open in new Window" />
</h:form>
This however affects all non-ajax(!) actions which are performed in the very same form. So if you're smart, make the action which shouldn't open in a new window an ajax action. However, ajax is also JavaScript and you mentioned that you don't want to use JS (I hope you don't get shocked once you discover that PrimeFaces is actually full of JavaScript).
If you absolutely need to restrict it to a single action, then you really can't go around asking little help to JavaScript.
<h:form>
...
<h:commandButton value="Open in new Window" onclick="this.form.target='_blank'" />
</h:form>
When you restrict the target only to a single action, maybe you want to get the form in its initial state.
With the oncklick action you set the target of the form to a _blan page.
After the click, the page is opened in a new tab/page (triggers the action event).
At last, the onblur action is triggered and set the form again to its initial state (the rest of the buttons will open in the _self page)
With this code, you can restrict to only a h:commandbutton to open in a new page.
The rest of the buttons will be opened in the self page:
<h:commandButton
onclick="this.form.target='_blank'"
onblur="this.form.target='_self'"
id="listadoRebuts"
action="#{giaquaBusquedaCorte.abrirListadoRebuts}"
value="#{msg.seqVisorbtnRecibos}">
</h:commandButton>
I have a h:commandlink control in page1. the control uses f:ajax to call to the following h:panelgroup :
I have a h:panelgroup control in page2 (a snippet), which has a ui:include within it.
I have a h:panelgroup control in page3 (a snippet), which has a ui:include within it.
Now according to the choices made on page1, I would like to switch the snippets by clicking on the h:commandlink control.
I have a BIG problem there: it seems that only if I click twice on the commandlink, only then the snippet changes - and not on one click.
I have tried to remove the f:ajax to render the panelgroup, and still it does not work...
There are two potential causes of this problem.
The <f:ajax> is fully re-rendering another <h:form> than where it is sitting in. This way the view state of the other form will get lost which would require invoking the action on the other form twice before it really get executed.
The solution is to not re-render the other <h:form>, but only some container component in that form. E.g.
<h:form id="otherForm">
<h:panelGroup id="content">
...
<h:panelGroup>
</h:form>
with
<f:ajax render=":otherForm:content" />
When there's a rendered attribute on the <h:commandLink> or any of its parent components, then it must evaluate true during the apply request values phase of the postback request in order to get JSF to invoke the bean action associated with the <h:commandLink> during the invoke action phase of that request. Perhaps the bean is request scoped and/or some odd/illogical flow inside the bean caused that the rendered attribute is not properly been preserved.
Best is to maintain those rendered conditions in a #ViewScoped bean and let its action methods return void or null so that the bean lives as long as you're interacting with the same view. Change the rendered conditions during action methods only and not inside setters/getters or something.
I have a JSF page on which I want to have a checkbox that, when clicked, will add/remove certain other form fields from the page. Here is the (simplified) code I currently have for the checkbox:
<h:selectBooleanCheckbox title="showComponentToReRender" value="#{backingBean.showComponentToReRender}">
<a4j:support event="onsubmit" reRender="componentToReRender" />
</h:selectBooleanCheckbox>
Here is the code for the component I want to hide:
<h:selectOneMenu id="componentToReRender" value="#{backingBean.value}" rendered="#{valuesList.rowCount>1 && backingBean.showComponentToReRender}">
<s:selectItems value="#{valuesList}" var="value"/>
</h:selectOneMenu>
Currently, clicking the checkbox does nothing; that "selectOneMenu" will not go away. What am I doing wrong?
You need to wrap the componentToReRender in either:
<h:panelGroup id="componentToReRenderWrapper">
or
<a4j:outputPanel id="componentToReRenderWrapper">
So, effectively you will have:
<h:panelGroup id="componentToReRenderWrapper">
<h:selectOneMenu id="componentToReRender" value="#{backingBean.value}" rendered="#{valuesList.rowCount>1 && backingBean.showComponentToReRender}">
<s:selectItems value="#{valuesList}" var="value"/>
</h:selectOneMenu>
</h:panelGroup>
and change the reRender="componentToReRenderWrapper" in case you use panelGroup, or remove that attribute, in case you use outputPanel.
Found the exact explanation in the RichFaces docs:
Most common problem with using reRender is pointing it to the component that has a "rendered" attribute. Note, that JSF does not mark the place in the browser DOM where the outcome of the component should be placed in case the "rendered" condition returns false. Therefore, after the component becomes rendered during the Ajax request, RichFaces delivers the rendered code to the client, but does not update a page, because the place for update is unknown. You need to point to one of the parent components that has no "rendered" attribute. As an alternative, you can wrap the component with layout="none" .
Don't forget to set ajaxRendered="true" on the a4j:outputPanel