<p><h:commandLink value="Apply Now" action="register" /></p>
when i writing code above, exception below throws:
[2/12/10 11:24:29:535 CST] 0000005f renderkit W Component j_id26 must be enclosed inside a form.
Is it a best practices to wrap a h:form tag in the jsf template page, and then every page using the template can just directly use the h:commandLink tag without hesitate on the h:form tag?
In my opinion <h:form> and <f:view> shouldn't be in the template page, because:
you can't customize their attributes, like (notably: enctype or beforePhase)
you may want multiple forms in a page.
you may at some point, in some places need to replace <h:form> with <a4j:form> (for example)
If you have many, very simple pages, then you can make an alternative template, which includes the main template, and which adds <f:view> and <h:form>.
Related
I have a question about the idea behind the fact, that only UIForm got the attribute prependId. Why is the attribute not specified in the NamingContainer interface? You will now probably say that's because of backward compability but I would preferre breaking the compability and let users which implement that interface, also implement methods for the prependId thing.
The main problem from my perspective about the prependId in the UIForm component is, that it will break findComponent()
I would expect that if I use prependId, then the NamingContainer behaviour would change, not only related to rendering but also when wanting to search for components in the component tree.
Here a simple example:
<h:form id="test" prependId="false">
<h:panelGroup id="group"/>
</h:form>
Now when i want to get the panelGroup component I would expect to pass the string "group" to the method findComponent(), but it won't find anything, I have to use "test:group" instead.
The concrete problem with that is, when using ajax with prependId="false". The ajax tag expects in the attributes update and process, that the values care of naming containers. It's a bit strange that when I use prependId="false" that I have to specify the full id or path, but okay.
<h:form id="test" prependId="false">
<h:panelGroup id="group"/>
</h:form>
<h:form id="test1" prependId="false">
<h:commandButton value="go">
<f:ajax render="test:group"/>
</h:commandButton>
</h:form>
Well this code will render without problems but it won't update the panelGroup because it cannot find it. The PartialViewContext will contain only the id "group" as element of the renderIds. I don't know if this is expected, probably it is but I don't know the code. Now we come to the point where the method findComponent() can not find the component because the expression passed as parameter is "group" where the method would expect "test:group" to find the component.
One solution is to write your own findComponent() which is the way I chose to deal with this problem. In this method i handle a component which is a NamingContainer and has the property prependId set to false like a normal UIComponent. I will have to do that for every UIComponent which offers a prependId attribute and that is bad. Reflection will help to get around the static definition of types but it's still not a really clean solution.
The other way would be introducing the prependId attribute in the NamingContainer interface and change the behaviour of findComponent() to work like described above.
The last proposed solution would be changing the behaviour of the ajax tag to pass the whole id, but this would only solve the ajax issue and not the programmatic issues behind the findComponent() implementation.
What do you think about that and why the hell is it implemented like that? I can't be the first having this problem, but I wasn't able to find related topics?!
Indeed, UIComponent#findComponent() as done by <f:ajax render> fails when using <h:form prependId="false">. This problem is known and is a "Won't fix": JSF spec issue 573.
In my humble opinion, they should never have added the prependId attribute to the UIForm during the JSF 1.2 ages. It was merely done to keep j_security_check users happy who would like to use a JSF form with JSF input components for that (j_security_check requires exact input field names j_username and j_password which couldn't be modified by configuration). But they didn't exactly realize that during JSF 1.2 another improvement was introduced which enables you to just keep using <form> for that instead of sticking to <h:form>. And then CSS/jQuery purists start abusing prependId="false" to avoid escaping the separator character : in their poorly chosen CSS selectors.
Just don't use prependId="false", ever.
For j_security_check, just use <form> or the new Servlet 3.0 HttpServletRequest#login(). See also Performing user authentication in Java EE / JSF using j_security_check.
For CSS selectors, in case you absolutely need an ID selector (and thus not a more reusable class selector), simply wrap the component of interest in a plain HTML <div> or <span>.
See also:
How to select JSF components using jQuery?
How to use JSF generated HTML element ID with colon ":" in CSS selectors?
By default, JSF generates unusable ids, which are incompatible with css part of web standards
I am using the Facelet Templating Technology to layout my page in a JSF 2 app that I am working on.
In my header.xhtml, primefaces requires that menubar be enclosed in h:form.
<h:form>
<p:menubar autoSubmenuDisplay="true">
Menu Items here!
</p:menubar>
</h:form>
So, in my contents pages, I will have another h:form or more.
Will it just work if I just place the h:form in my template.xhtml?
<h:body>
<h:form>
<div id="top">
<ui:insert name="header"><ui:include src="sections/header.xhtml"/></ui:insert>
</div>
<div>
<div id="left">
<ui:insert name="sidebar"><ui:include src="sections/sidebar.xhtml"/></ui:insert>
</div>
<div id="content" class="left_content">
<ui:insert name="content">Content</ui:insert>
</div>
</div>
<div id="bottom">
<ui:insert name="footer"><ui:include src="sections/footer.xhtml"/></ui:insert>
</div>
<h:form>
</h:body>
I am actually thinking of a use case where I need multiple h:form in a page.
Thanks
You can safely use multiple forms in a JSF page. It's not different than when using plain HTML.
Nesting <form> elements is invalid in HTML. Since JSF just generates a bunch of HTML, it's not different in JSF. Nesting <h:form> is therefore also invalid in JSF.
<h:form>
...
<h:form> <!-- This is INVALID! -->
...
</h:form>
...
</h:form>
The browser behavior as to submitting a nested form is unspecified. It may or may not work the way you expect. It may for instance just refresh the page without invoking the bean action method. Even if you move the nested form (or a component that contains it) outside of the parent form with dom manipulation (or by e.g. using the PrimeFaces appendTo="#(body)"), it still won't work and there should be no nested forms at time of loading the page.
As to which forms you need to keep, having a single "god" <h:form> is actually a poor practice. So, you'd best remove the outer <h:form> from the master template and let the header, sidebar, content etc sections each define its own <h:form>. Multiple parallel forms is valid.
<h:form>
...
</h:form>
<h:form> <!-- This is valid. -->
...
</h:form>
Each form must have one clear responsibility. E.g. a login form, a search form, the main form, the dialog form, etc. You don't want to unnecessarily process all other forms/inputs, when you submit a certain form.
Note thus that when you submit a certain form, other forms are NOT processed. So, if you intend to process an input of another form anyway, then you've a design problem. Either put it in the same form or throw in some ugly JavaScript hacks to copy the needed information into a hidden field of the form containing the submit button.
Within a certain form, you can however use ajax to limit the processing of the inputs to a smaller subset. E.g. <f:ajax execute="#this"> will process (submit/convert/validate/invoke) only the current component and not others within the same form. This is usually to be used in use cases wherein other inputs within the same form need to be dynamically filled/rendered/toggled, e.g. dependent dropdown menus, autocomplete lists, selection tables, etc.
See also:
commandButton/commandLink/ajax action/listener method not invoked or input value not set/updated - point 2
What is <f:ajax execute="#all"> really supposed to do? It POSTs only the enclosing form
Understanding PrimeFaces process/update and JSF f:ajax execute/render attributes
<p:commandbutton> action doesn't work inside <p:dialog>
I was confounded by this issue for a while. Instead of a series of independent forms, I converted to a template, that is, rather than making a call to a xhtml with listed forms, usually as ui:include, I make a call to those formerly ui:included xhtml pages that ui:content captured in a parent template.
In my app I have tutor and student as roles of user. And I decide that main page for both will be the same. But menu will be different for tutors and users. I made to .xhtml page tutorMenu.xhtml and student.xhtml. And want in dependecy from role include menu. For whole page I use layout and just in every page change content "content part" in ui:composition.
In menu.xhtml
<h:body>
<ui:composition>
<div class="menu_header">
<h2>
<h:outputText value="#{msg['menu.title']}" />
</h2>
</div>
<div class="menu_content">
<с:if test="#{authenticationBean.user.role.roleId eq '2'}">
<ui:include src="/pages/content/body/student/studentMenu.xhtml"/>
</с:if>
<с:if test= "#{authenticationBean.user.role.roleId eq '1'}">
<ui:include src="/pages/content/body/tutor/tutorMenu.xhtml" />
</с:if>
</div>
</ui:composition>
I know that using jstl my be not better solution but I can't find other. What is the best decision of my problem?
Using jstl-tags in this case is perfectly fine, since Facelets has a corresponding tag handlers (that are processed in the time of view tree creation) for the jstl tags and handles them perfectly. In this case c:if could prevent processing (and adding the components located in the included xhtml file) of the ui:include which leads to reduced component tree and better performance of the form.
One downside of using this approach is that you cannot update these form parts using ajax, i.e. you change the user role and refresh the form using ajax, because the ui:include for the other role is not part of the view anymore. In such case you have to perform a full page refresh.
Is there a JSF 2.1 component which lets me conditionally render (or not render) all its content? Something like
<h:component rendered="#{user.loggedIn}">
...a bunch of jsf components and HTML code...
...even more HTML code...
</h:component>
I am using PrimeFaces 3M4 as this may influence your answer!
<h:panelGroup>
If you set attribute layout="block", you will have a <div> tag
Otherwise, you have a <span> tag.
In general most of jsf components support the render attribute (never bumped in some that does not),
container components like h:panelGrid or h:panelGroup supports the rendered attribute and if its set to false all its child will be hidden too
Same goes for the primefaces components ,and if not it probably a bug (i think there was an issue with tabview of primefaces)
Here's a link for primefaces user guide, you can find supported attributes of all primefaces components there User’s Guide for 3.0.M4
i have a problem to generate dynamic menu, i'm using JSF1.2. I tried the c:forEach with an arrayList to generate dynamic rich:panelMenu as BalusC advised in a related forum, but get Accessor never triggered in c:forEach. it ruined me a day. can anyone provide me a solution ?
<c:forEach items="#{serviceListBean.services}" var="child">
<rich:panelMenuItem mode="none">
<h:outputText value="#{child.serviceId}"></h:outputText>
</rich:panelMenuItem>
</c:forEach>
what's wrong in this code? can anyone enlighten me?. For info, serviceListBean is request scoped bean.
Two possible causes:
JSTL is not declared as taglib in JSP or Facelets. To confirm this, rightclick page in browser and choose View Source. Do you see <c:forEach> tag unparsed among the generated HTML? If you're using JSP, declare it as follows:
<%#taglib prefic="c" uri="http://java.sun.com/jsp/jstl/core" %>
Or if you're using Facelets, declare it as follows in root element:
xmlns:c="http://java.sun.com/jsp/jstl/core"
On some servers like Tomcat, which doesn't ship with JSTL out the box, you would also need to install JSTL first, see also this info page.
This piece of code is in turn been placed inside a JSF repeating component, like <h:dataTable> with a var="serviceListBean". This is also not going to work. You would need to replace the JSF repeating component by <c:forEach> as well.