In the JavaServer Faces documentation it is written that it is possible to use different view declaration languages.
But, Facelets apart, it is impossible for me to find other view declaration languages to use with JavaServer Faces.
Where can I find other view declaration languages for JavaServer Faces?
It just hasn't happened - view definition languag is an extension point in the specs, but no other VDL emerged (maybe it will?). The only actually used methods of building JSF views is the deprecated JSP way or the common Facelets way.
It looks like people are more interested in dynamically building component trees in code - but this area of JSF is also surprisingly tricky to get right (it's supposed to be improved in JSF 2.3).
Related
Regarding the <composite:interface> tag for JSF composite components, what is the use of the "expert" property of the (interface tag](https://docs.oracle.com/javaee/7/javaserver-faces-2-2/vdldocs-facelets/cc/interface.html)?
The description is awfully vague and I found no references to its use or documentation online.
What is its purpose and usage?
I've scanned the Mojarra source code. It's ultimately set in java.beans.FeatureDescriptor class.
But it's in turn not really anywhere used.
With this I conclude that it's just unused inherited logic. The same applies to dislayName, shortDescription, hidden and preferred attributes. Only the name and componentType are actually concretely used.
The unused attributes are at most only used by tooling such as IDEs like Eclipse and Netbeans so that they can parse and show the right labels and tooltips here and there when working with (custom) composite components.
i work on a project where we use JSF + Primefaces
I would like to know if it's preferable to use JSF components as much as possible even if there are sometimes the same components in Primefaces (for basic use)
Using Primefaces only for specific things not available on the JSF version
When should we use Primefaces instead of JSF ?
sorry for any faults
In general, I'd say prefer them than JSF standard components, the reason is simple: CSS skinning. For example, even if h:inputText and p:inputText are exactly the same component, you might want to have the same CSS skinning for all JSF components (specially if you use a premium layout from PF)
But, I think there are few exceptions:
If you use JSF 2.3. For example, I'd rather use h:commandScript than p:remoteCommand. As they're not "visual" components, I'd prefer to use standard components. See also what works better for you ;-)
Also, Oleg presents some performance killer using PF components in datatable, see here http://ovaraksin.blogspot.com/2013/05/jsf-choice-between-legacy-components.html
I think the most important point is consistency, which comes in a couple of flavours.
PrimeFaces (PF) components have a lot of styling put on them (through the theme options). If you use PF components throughout your application, you'll get a consistent style. If you mix PF and JSF components this will look messy.
PF components have a particular way of doing things - organising options, defining ajax calls etc. While it's important to know how the JSF stuff works underneath, using PF components consistently will make your code consistent too.
Finally, in many cases PF components are exact replacements for JSF components, but often with extra features added. There's no reason not to take advantage of them.
Better choose one of them and develop all application using mainly one stack. Will be easy to support, easy update, easy bug fix.
Primefaces at the moment good choose.
when using CombinedResourceHandler in a Richfaces application only stylesheets and user defiend scripts are combined. The standard JavaScript resource and all Richfaces specific resources remain as seperated resources.
The Omnifaces documentation states:
RichFaces has the same problem with several JS files, but this is so far not exactly trivial to workaround
So my question is what this 'non-trivial workaround' would be?
As far as I can see, CombinedResourceHandler wont handle resources when getRendererType() returns org.richfaces.renderkit.ResourceLibraryRenderer. These are then handled by org.richfaces.renderkit.html.ResourceLibraryRenderer.
I am not sure what would be the best way to combine RichFaces behaviour with OmniFaces here.
I was able to create a solution by modifying OmniFaces CombinedResourceHandler.
Details in short:
Richfaces utilizes a concept called ResourceLibrarys wich means a resource may not only be a single file but instead a collection of those files. For example, RichFaces uses a resource named base-component.reslib. RichFaces ResourceHandler interpretes this resource dependency as dependency to
javax.faces:jsf.js
jquery.js
richfaces.js
richfaces-base-component.js
So the CombinedResourceHandler needed some extra functionality to seperate dependencies to ordinary Resources from Richfaces ResourceLibraries. The latter needed to be resolved according to specifications obtained from RichFaces sources.
It was not trivial to work this around without modifying the CombinedResourceHandler itself. The CombinedResourceHandler itself has really to be modified to use a reflection hack which extracts the resources from RichFaces' org.richfaces.resource.ResourceLibraryFactoryImpl. The reflection hack is necessary in order to keep OmniFaces free of RichFaces dependencies so that it can be used together with other component libraries like PrimeFaces.
As per issue 107, this was implemented in 1.3-20121206.
Jsf 1.x compiles jsp into servlet, jsf 2 use vdl instead of jsp, I wonder what is the source of performance gain compared to jsf 1.x?
The most important reasons why JSF 2 performs better are:
Use a fast SAX parser instead an static compiler (facelets): An Abstract Syntax Tree (AST) is built and keep in memory, so further request don't require parse the xml once built and component tree creation is done without extra steps.
Partial State Saving algorithm (taken from MyFaces Trinidad).
If you are looking on MyFaces 2.0.x/2.1.x, you'll get these improvements too:
Refresh build view when necessary (MyFaces 2.0.x/2.1.x specific): Only refresh view on PSS on postback when necessary (see org.apache.myfaces.REFRESH_TRANSIENT_BUILD_ON_PSS).
Caching EL expressions when necessary (coming soon on MyFaces 2.0.8/2.1.2): EL expressions are cached wit the AST, so no extra EL parsing per request is done. (see MYFACES-3160 for details)
JSF 2 is a big step in the righ direction.
I have been involved in JSF + Facelets dev for a month or so. I used composition, insert, define and other tags from facelets. I am finding it difficult to understand what facelets really give me? What are its alternatives ? What is that View Handler technology?I am not able to find good material / online notes on the same. Can someone explain in laymen terms - What it is? Thanks
Facelets is a view technology. Facelets is the successor of JSP. The only alternative as far is JSP, which has almost no seamless support for JSF components. If you leave Facelets aside and step back to JSP, then the real advantages of Facelets will be quickly clear.
You may find my answer in the question useful as well: What is the difference between JSF, Servlet and JSP? Facelets is also covered in there.
Without providing a complete academic background on Facelets, here's what it really gives you:
First, the ability to create reusable HTML code that you write yourself: this is not possible with JSF (pre-v2). Facelets gives you more control over the output of your webpages.
It has been demonstrated in some editors you can preview parts of
your page this way as well, but in reality this is impractical as the
webpage has many states of which only the initial bare version would
be visible in the preview.
If you are going to use JSF for a public website, Facelets are a must
for SEO, considering that with JSF you have no control whatsoever of
what comes out of the standard JSF components.
Second: templating. The ability to define blocks of HTML (read: Facelet compositions) that can be reused using tags such as ui:define and ui:insert.
There are other benefits, but right now you should know that these two are why you are using Facelets over JSF. Also, JSF 2.0 by default contains a modified version of Facelets.
benefits of facelets: http://www.ibm.com/developerworks/java/library/j-facelets/