I am using PrimeFaces p:messages but I think this question applies equally to h:messages
I have a composite component to handle login/logout at the top of every page. (It is in the Facelets template.) To handle login errors, it has a p:messages component in it.
In the content area, I typically have a form that also has a p:messages in it. However if the form processing ever produces a message, I end up getting a message rendered from the login component as well as the place where I intended.
This is hardly a fatal problem, but I would like to clean this up. Any suggestions?
Primefaces p:messages has an attribute redisplay. Set
redisplay="false"
to instruct the message tag to only display messages that are not yet displayed on the page.
Related
I have a <h:panelGrid> and a h:commandLink(link is basically a image).Now I want that on mouseover event , Then link should be render(render='true') and on mouseout event, it gets removed render='false'.But I am unable to create the logic that How can I do this with these events as the approach I am using is To set the values of bean true and false on this event.
Here is my code
<h:form>
<h:panelGrid mouseover='** we cannot call a bean method here which changes the bean value **'>
This is the Div On which I want to apply mouseover event
</h:panelGrid>
<h:commandLink id="btn" render={renderBean.renderLink}>
<h:graphicImage url="image.jpg"/>
</h:commandLink>
</h:form>
The default value of renderLink attribute of renderBean is false. Now I want to know the way that How can I change its value to true on mouseover event? Is it possible? OR Anyother solution in JSF w.r.t this requirement
You have to remember in JSF that the page will first be processed server-side by the JSF engine in the web server. At that time all JSF tags will be converted into their HTML equivalent. The render attribute tells the server-side engine whether or not to output an HTML a (anchor) link in the place of the <h:commandLink> element.
The behavior you're looking for, namely responding to mouse events, is client-side functionality. It happens in the browser, not at the web server, so no JSF is involved. The solution is to handle the mouse events in JavaScript, not JSF. You will typically set (or remove) the CSS attribute display:none on the id called btn (unfortunately it's slightly more complex as JSF will mangle the element id a bit). There are lots of posts here on StackOverflow that deal with how to handle client-side events in JavaScript. Using jQuery for example is a really common approach.
I recommend to get started you take a look at the blog of one of our best JSF resources and long-time StackOverflow user BalusC: http://balusc.blogspot.com.
There's a lot to learn and you'll get a good start by going there first (and searching for his posts on SO).
Good luck.
I have a composite component, which represents an item that will be stored in a list. I would like to display these items using <ui:repeat>, but I have problems making ajax calls. The thing is that for <f:ajax> render attribute, I want to give the id of my component through
#{cc.clientId}
However this raises error when I use it with <ui:repeat>, because of the reasons that are explained in this document https://rogerkeays.com/jsf-c-foreach-vs-ui-repeat.
<cc:implementation>
<div id="#{cc.clientId}">
<h:form>
<h:commandLink styleClass="btn btn-info" value="Click me">
<f:ajax execute="#form"
render=":#{cc.clientId}"/>
</h:commandLink>
</h:form>
</div>
</cc:implementation>
Is there a way to make the above component work using <ui:repeat> (for example is there a component which can replace the <f:ajax> tag handler, or are we stuck to <c:forEach> construct)?
<ui:repeat id="myComponent" value="#{backingBean.myComponentItem}" var="item" varStatus="itemIndex">
<components:exampleComponent id="myComponent"/>
</ui:repeat>
So I start using <c:forEach> instead of <ui:repeat>, and I was able to use the id of my component in the render attribute of <f:ajax>. But this time when I make pagination, if the size of the list decreases I start having empty components in my page. For solving this I started doing pagination through ajax calls and this solved the empty component problem.
Just I thought everything was solved I encountered another problem: lets say I have a page listing 10 components, and I went to another page, and from that page I came to the component displaying page again, but for some reason lets say this time I retrieved only 3 items from database, and I just want to display these 3 items through my components but nothing else.. Unfortunately in this scenario, 3 items are displayed correctly, but the page also contains 7 empty components too. For overcoming this I need to redirect to this page one-more time. So I just gave up at this point. Apart from this I also eventually get the exception below, when the number of the components on the page changes.
java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to com.sun.faces.application.view.StateHolderSaver
I tried using the suggestion explained in the post Jsf Error : java.lang.ClassCastException, but it didn't work for me, I started getting another error which is similar to above exception.
<context-param>
<param-name>javax.faces.FULL_STATE_SAVING_VIEW_IDS</param-name>
<param-value>/pagename.xhtml</param-value>
</context-param>
So after these long explanations I would just like to learn what is the best approach for creating composite components which are ajax-enabled, who are fully responsible of their own-states and independent of other components, and that can be displayed in the page more than once and the number of components may vary during the page life-cycle (through pagination, navigation etc).
So far the best solution I came up with is, to check number of components in the page and when that number changes through an ajax call or because of a navigation from another page, redirect to the destination page one more time, this refreshes the empty components in the page without creating much disturbance to users. If you come up with any better solution please let us know.
In my JSF 2.0 application, whenever validation fails, I display a message to the user with <h:message> tag. I always get one extra message at the top of the page along with the expected one. How can I get rid of this?
Apparently you're using a <h:messages> in the top of the page. If you set it to display global messages only (those with a null client ID, as in context.addMessage(null, message)), then the client-specific message won't be duplicated over there.
<h:messages globalOnly="true" />
In earlier projects I often used an s:button or s:link from Seam 2 when caceling something, because it wouldn't submit the form and thus no model updates occured.
Now I switched to WELD + Seam 3 and couldn't find it there anymore - am I just blind or do I have to use something else?
Geziefer
You can do it in plain JSF 2.0 by setting immediate attribute to true in the h:commandButton.
From the MyFaces wiki:
The immediate attribute can be used to achieve the following effects:
Allow a commandLink or commandButton to navigate the user to
another page without processing any data currently in input fields of
the current screen. In particular, this allows navigation to occur
even when there are currently validation errors. A "cancel" button
typically falls into this category.
Allow a commandLink or commandButton to trigger back-end logic
while ignoring validation for some of the fields on the screen. This
is a more general version of the item above.
Make one or more input components "high priority" for validation,
so that if any of these are invalid then validation is not performed
for any "low-priority" input components in the same page. This can
reduce the number of error messages shown.
I found a way to handle it by using the commandButton from RichFaces 4 and setting bypassUpdates to true:
<a4j:commandButton value="Cancel" action="#{myHandler.cancel}"
bypassUpdates="true" render="myTable" />
For me this solution is ok, since I'm allready using RichFaces 4 - but I'm still interested, how to solve this with standard JSF 2.0?
Sometimes, if I click a commandButton that calls an action method, it will just do a page refresh without actually calling the method!
I set a breakpoint in that method and if this behavior takes place, the method is not called. What is also strange about it: It also does that if I didn't fill values in input components that have "required=true". I would expect that a valdiation error appears. The error appears only if the action method would be called fine. But not if it will just issue that strange page refresh.
The call looks pretty normal and works in most cases:
<h:commandButton value="Do something"
action="#{bean.doSomething(someBean.value)}" />
I can't exactly figure out when this behavior appears (and when not), but it should have something to do with the values chosen in some of the other components. But... how?
(I have two forms in a xhtml file. I just mention that because I don't know if it is important or not. However, there are no nested forms and h:messages displays nothing after page refresh.)
I'm using JSF 2 (MyFaces) + Tomahawk.
there are no nested forms and h:messages displays nothing after page refresh
You've likely a rendered attribute on the component or one of its parents which evaluated false during the processing of the form submit request. You need to ensure that it evaluates the same as it did during displaying the page. You can do this by putting the bean responsible for this in the view scope instead of the request scope.
See also:
commandButton/commandLink/ajax action/listener method not invoked or input value not updated