What is the difference between <f:subview> and <ui:composition> tags? For what purposes and cases are each of these tags suiteble for?
The <f:subview> introduces a new NamingContainer layer and has initially (in JSF 1.0) been designed to be used in combination with JSP's <jsp:include> tag.
<f:subview id="foo">
<jsp:include page="/WEB-INF/include.jsp" />
</f:subview>
In JSF 2.0, which uses Facelets instead of JSP as default view technology, this tag has not really a value anymore.
The <ui:composition>, which is from JSP's successor Facelets, definies a template composition and allows the developers to design the HTML template in visual HTML editors like Dreamweaver. When actually used in a JSF/Facelets environment, any content outside <ui:composition> will be disregarded and only the inner content will be used to build the component tree. This tag can be used in both the include pages and template clients. See also How to include another XHTML in XHTML using JSF 2.0 Facelets?
Related
I am following the Java EE6 tutorials and I don't understand the difference between JSF and Facelets. Chapter 4 goes has a section 'Developing a Simple JavaServerFaces Application' and Chapter 5 has a section 'Developing a simple Facelets' application and as far as I can see both these examples use the exact same process - an .xhmtl page for the markup, a backing bean to hold some data and then a web.xml file that maps urls to the 'FaceletsServlet'.
From what I can gather Facelets are .xhtml pages with tags such as <h:head> and <h:inputText> used to mark up the webpages.
But then what is JSF? I have read that either JSP or Facelets can be used with JSF so does that mean the role of JSF is to provide the tag libraries that are used by JSP or Facelets?
JSF - Java Server Faces is the overarching application development framework. It contains many aspects, one of which is the view handler. JSF (Wikipedia), JSF (Stack Overflow).
Facelets is a view handler for JSF. Before JSF 2.0, JSP was the default view handler, but the problem was JSP didn't work very well with JSF's component based framework. Facelets was designed from the ground up to work well with JSF. Facelets (Wikipedia), Facelets (Stack Overflow)
Tag libraries are a different part of the JSF spec. They are collections of UI components. Facelets is not a taglib, and many tag libs can be used with Facelets.
JSF is as you probably already gathered a component based system. These components are organized in libraries.
JSF is the base standard and defines the standard taglibs core and html. These include the tags for such basic elements as input fields, buttons, labels and links. Facelets is the facelets taglib, it was originally distributed seperatly but now it is included in the JSF standard. Facelets contains tags like ui:composition, ui:insert and ui:define that can be used for templating. There are many other tag libraries that can be used with JSF like primefaces, richfaces, tomahawk and trinidad.
JSF is used with Facelets, before we were using jsp. Facelet is a view technology based on xml.
Facelets was originally created as a separate, alternative view declaration language for JSF 1.1 and JSF 1.2 which both used JSP as the default view declaration language. Starting from JSF 2.0, Facelets has been promoted by the JSF expert group to be the default view declaration language. JSP has been deprecated.
Important features facelets provides are templating, composite components, content reuse.
http://www.ibm.com/developerworks/library/j-facelets/
I have DIV element with a header style enclosing a h:outputText but when the page renders i see the HTML is formed in such a way that my div doesnot contain the label generated by the h:outputText instead i see the label above my DIV . Am i doing it wrong? i tried f:verbatim but didn't help either
Based on your question history you're using the ancient JSF 1.1. The <f:verbatim> way should work. Perhaps you've enclosed JSF components inside <f:verbatim>. You should not do that. It should only contain raw HTML.
<f:verbatim><div></f:verbatim>
<h:outputText value="Some text." />
<f:verbatim></div></f:verbatim>
Since JSF 1.2 the <f:verbatim> is not necessary anymore. JSF 1.2 should work on all environments where JSF 1.1 is been used. I strongly recommend to upgrade.
See also:
Mix HTML and JSF in a JSF subview
What are the main disadvantages of Java Server Faces 2.0? (a bit of history)
w.r.t. How to execute action on GET request with f:viewParam?
<f:metadata>
<f:viewParam name="id" value="#{tInputBean.id}" />
<f:event type="preRenderView" listener="#{tInputBean.init}" />
</f:metadata>
I'm interested to know whether it matters if a preRenderView f:event is placed inside the f:metadata or not. I've checked the Java EE6 tutorial, Java Server Faces 2.0 Complete Reference, and Core JSF2, and none of them have examples of f:event inside f:metadata, but I've seen lots of examples online like this.
JSF2 Compl.Ref says p.540
The f:metadata tag encapsulates the set of elements used to specify
the metadata for a Facelet view, and therefore must be a child of the
f:view tag and may not appear in a template. As of JSF2.0, the only
purpose of this tag is to encapsulate f:viewParam tags.
Does placing the f:event (often used to support an f:viewParam) inside the f:metadata have a special meaning, or is it just to help group it alongside the f:viewParam visually/logically ?
No, the <f:event> is not strictly required to be placed inside <f:metadata>. It can be attached to any component. It's indeed for pure self-documentary purposes placed inside the <f:metadata> whenever you have a bunch of <f:viewParam>s and would like to hook a <f:event> to invoke an action after all those view parameters have been set. It can even be placed outside/before those <f:viewParam>s, but it makes the code not more self-documenting.
Note that in the upcoming JSF 2.2, a new <f:viewAction> tag will be introduced which in turn is supposed to replace the <f:event type="preRenderView"> in the <f:metadata>.
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.
Eg: h:inputText will render a "input type='text'".
What jsf tag can render a "div" tag?
You can create a DIV component using the <h:panelGroup/>.
By default, the <h:panelGroup/> will generate a SPAN in the HTML code.
However, if you specify layout="block", then the component will be a DIV in the generated HTML code.
<h:panelGroup layout="block"/>
In JSF 2.2 it's possible to use passthrough elements:
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:jsf="http://xmlns.jcp.org/jsf">
...
<div jsf:id="id1" />
...
</html>
The requirement is to have at least one attribute in the element using jsf namespace.
Apart from the <h:panelGroup> component (which comes as a bit of a surprise to me), you could use a <f:verbatim> tag with the escape parameter set to false to generate any mark-up you want. For example:
<f:verbatim escape="true">
<div id="blah"></div>
</f:verbatim>
Bear in mind it's a little less elegant than the panelGroup solution, as you have to generate this for both the start and end tags if you want to wrap any of your JSF code with the div tag.
Alternatively, all the major UI Frameworks have a div component tag, or you could write your own.
you can use myfaces tomahawk component
http://myfaces.apache.org/tomahawk-project/tomahawk12/tagdoc/t_div.html
I think we can you use verbatim tag, as in this tag we use any of the HTML tags