I want to create links using database columns. I have a backing bean where I 'm connecting to the database. There is no problem with the connection and also no problem with the links names. I can see my links on my browser. I want to use onclick function and that's exactly where the problem starts. How can I use or can I use EL in onclick?
A little example:
<h:dataTable rows="7" value="#{frontSiteMenu.links}" var="row"
styleClass="sitemenu" width="200">
<h:column>
<h:outputText value='#{row.newsGroup}' />
</h:column>
</h:dataTable>
Thanks.
I take it you are using JSPs?
Use h:outputLink instead of an a tag and change the expression use the # character:
<h:outputLink value="#" onclick="dispNewsGroup('#{row.newsGroupId}')">
<h:outputText value='#{row.newsGroup}' />
</h:outputLink>
That is untested, but should be close to what you want.
The spec says this about # vs $:
...by convention the J2EE
web tier specifications use the
${expr} construct for immediate
evaluation and the #{expr} construct
for deferred evaluation.
So, in a repeat control where the underlying values change, it is desirable to use deferred evaluation.
There are also issues with using non-JSF tags as children of some JSF controls, so it is best to stick to using JSF controls where possible (though there is a f:verbatim tag). Many of these issues go away if you move to the newer Facelets view technology.
Related
I'm using Primefaces 5.1. In my student I need style particular style in particular text.Below code I try It will show error(The value of attribute "value" must not contain the '<' character). So I replace < to &< and &> for > that time I faces error(The entity name must immediately follow the '&' in the entity reference)
<p:outputPanel>
<h:outputText styleClass="noWrap" escape="false"
value="#{common.ConfirmMessage1} <b style='color:red'>'
#{student.numberOfUserFound}'</b>"/>
</p:outputPanel>
My doubt is separate text is solution or any other way?
Just don't use <h:outputText>. It has no technical necessity in this specific case.
<p:outputPanel>
<span class="noWrap">
#{common.ConfirmMessage1}
<b style='color:red'>'#{student.numberOfUserFound}'</b>
</span>
</p:outputPanel>
See also:
Is it suggested to use h:outputText for everything?
That being said, I suggest to take a step back from JSF and start learning some basic HTML first. JSF will then be easier to understand. In the context of this question, JSF is just a HTML code generator.
I'm trying to use the setPropertyActionListener tag to set a value in my backing bean. However, it doesn't work as I expected.
Context: userService is an instance of my backing bean, which contains an int member, reqID. This, in turn, is the key to a map of objects that belong to a class called User. I'm trying to create a page that will list all instances of User, and provide a button to visit a separate view that shows that particular User's information. To do this, I'm attempting to set userService.reqID to the id of the chosen User so it can generate a reference to that user for the next view (which is done in the call userService.toUserInfo).
If I use the xhtml snippet below:
<ui:define name="content">
<h:form>
<h:panelGrid>
<ui:repeat value="#{userService.UserList.getUserList()}" var="user">
<li>
<h:outputText value="#{user.name}" />
<h:commandButton value="View details of #{user.name}" action="#{userService.toUserInfo}">
<f:param name="id" value="#{user.id}" />
<f:setPropertyActionListener target="#{userService.reqID}" value="#{id}"/>
</h:commandButton>
</li>
</ui:repeat>
</h:panelGrid>
</h:form>
</ui:define>
The tag does not appear to evaluate id correctly and I get a Null Pointer Exception.
Earlier, I tried changing my setPropertyActionListenerTag so it read out as:
<f:setPropertyActionListener target="#{userService.reqID}" value="id"/>
which gave me an error, because the tag was sending the string "id" as opposed to the int value of the parameter.
Is there some way to force f:setPropertyActionListener to evaluate the expression under value? Or is there another tag that will allow me to do this?
Also, is ui:param used appropriately here?
The <f:param> (and <ui:param>) doesn't work that way. The <f:param> is intented to add HTTP request parameters to outcome of <h:xxxLink> and <h:xxxButton> components, and to parameterize the message format in <h:outputFormat>. The <ui:param> is intented to pass Facelet context parameters to <ui:include>, <ui:decorate> and <ui:define>. Mojarra had the bug that it also behaves like <c:set> without a scope. This is not the intented usage.
Just use <c:set> without a scope if it's absolutely necessary to "alias" a (long) EL expression.
<c:set var="id" value="#{user.id}" />
Put it outside the <h:commandLink> though. Also in this construct, it's kind of weird. It doesn't make the code better. I'd just leave out it.
<f:setPropertyActionListener ... value="#{user.id}" />
See also:
Setting ui:param conditionally
what is the scope of <ui:param> in JSF?
Defining and reusing an EL variable in JSF page
Unrelated to the concrete problem, if you're using EL 2.2 (as you're using JSF 2.2, you undoubtedly are as it requires a minimum of Servlet 3.0, which goes hand in hand with EL 2.2), then just pass it as bean action method argument without <f:setPropertyActionListener> mess. See also a.o. Invoke direct methods or methods with arguments / variables / parameters in EL and How can I pass selected row to commandLink inside dataTable?
<h:commandButton ... action="#{userService.toUserInfo(user.id)}">
On again another unrelated note, such a "View user" or "Edit user" request is usually idempotent. You'd better use <h:link> (yes, with <f:param>) for this. See also a.o. Creating master-detail pages for entities, how to link them and which bean scope to choose and How to navigate in JSF? How to make URL reflect current page (and not previous one).
Oh, that <h:panelGrid> around the <ui:repeat><li> doesn't make sense in HTML perspective. Get rid of it and use <ul> instead. See also HTMLDog HTML Beginner tutorial.
I hope that I understood JSF correct and this all makes sense. I try to do some kind of simple templating within a page by using (conditional) includes.
The panel is updated by a selection.
<p:outputPanel id="panel">
<h:panelGroup rendered="#{not empty someBean.selectedObject}">
<ui:include src="WEB-INF/pages/#{someBean.selectedObject.pageName}.xhtml" />
</h:panelGroup>
</p:outputPanel>
If I am right the ui:include got processed in some kind of view preparation phase and the rendered attribute just before the page gets rendered. As a result I get a FileNotFoundException because it tries to load WEB-INF/pages/.xhtml. This makes quite some sense to me, but how to solve this problem without a messy hackaround like creating an empty page as a prefix for the filename (page.xhtml) and prefix every page that should be actually rendered with this string (pageSamplePage.xhtml)?
You need to conditionally build the <ui:include> instead of conditionally render it. Use <c:if> instead of rendered.
<p:outputPanel id="panel">
<c:if test="#{not empty someBean.selectedObject}">
<ui:include src="WEB-INF/pages/#{someBean.selectedObject.pageName}.xhtml" />
</c:if>
</p:outputPanel>
Otherwise, the <ui:include> still ends up in the component tree.
See also:
JSTL in JSF2 Facelets... makes sense?
Unrelated to the concrete problem, even when you intend to conditionally render parts of the view, you'd better use <ui:fragment> instead of <h:panelGroup> as it has less overhead.
Prevent usage of <c:if>, as it can break some of the standard JSF components.
We observed that its usage caused duplication of a child within UI:Panel as a side-effect, and it took a while to identify this as the root-cause.
Hi in my project I need to visualize currency value, as far in my f:convertNumber
I use a fixed currencySymbol; everything is ok, but when I try to get the symbol with an expression language like this:
<h:outputText value="#{rowItem.value}">
<f:convertNumber currencySymbol="#{rowItem.getCurrencySymbol()}" groupingUsed="true" maxFractionDigits="2" type="currency" />
</h:outputText>
it is like the method getCurrencySymbol is not called, I am sure there is something I am missing.
That will happen if #{rowItem} is only available during view render time, such as when it's specified by <h:dataTable var="rowItem">, as the variable name itself already suggests. It can also happen if #{rowItem} gets changed between building the view and rendering the view, such as when it's coming from a dropdown component in the same form. The <f:convertNumber> is namely a taghandler, not an UI component. It gets executed during view build time, not during view render time. The desired #{rowItem} value is not per definition available during view build time.
This all is explained in JSTL in JSF2 Facelets... makes sense? In that answer, you can substitute "JSTL" with <f:convertNumber> as they both are taghandlers and thus have exactly the same lifecycle.
There's no solution in standard JSF API without creating a custom converter and changing the view or model. You can find possible solutions in this answer: How to set converter properties for each row/item of h:dataTable/ui:repeat?
The JSF utility library OmniFaces offers <o:converter> out the box for exactly this problem. Use it as follows:
<h:outputText value="#{rowItem.value}">
<o:converter converterId="javax.faces.Number" currencySymbol="#{rowItem.getCurrencySymbol()}" type="currency" />
</h:outputText>
(note that I omitted the other two properties as those are the default already when type="currency" is used)
I'm upgrading to JSF 2.0.2 inside Tomcat 7.0.12 and I have a page with a variable number of reusable widgets on it. I used to use t:aliasBean for this purpose, but it doesn't seem to work. I'm now trying the following in my Xhtml:
<c:forEach items="${viewBean.currentView.parts}" var="part">
<t:div styleClass="div#{viewBean.partNumber[part]}">
<c:forEach items="${part.widgets}" var="widget">
<f:subview id="div#{viewBean.widgetId[widget]}">
<ui:include src="widgets/#{widget.widgetPage}">
<ui:param name="widget" value="#{widget}" />
</ui:include>
</f:subview>
</c:forEach>
</t:div>
</c:forEach>
What seems to happen is the next widget from the loop is used in the previous widget's page, so I get errors unless there is only one widget.
Edit: I've tried ui:repeat - it doesn't work. I've also tried removing the ui:include, just as a sanity test; the looping works fine. Also, I'm using Spring 2.5.6.SEC01 - though it shouldn't matter.
I propose to use ui:repeat instead of c:forEach.
Why?
The most important thing to understand
about the jstl tags in Facelets is
that they do not represent components
and never become a part of the
component tree once the view has been
built. Rather, they are tags which are
actually responsible for building the
tree in the first place. Once they
have done their job they expire, are
no more, cease to be, etc etc.
Source [here][1]. I really recommend to read the entire article.
UPDATE:
Please note that I do not say that c:forEach is bad. I want to underline that mixing it with ui:repeat it's not recommended.
[1]: https://rogerkeays.com/jsf-c-foreach-vs-ui-repeat