I am trying to get the reusable group of jsf 1.2 components inside a panelgrid using Facelet tag file. #Balusc's previous answer at How to make a grid of JSF composite component? was a fabulous resource. I have a couple of followup questions:
In my c:when how do I test for the tagName itself instead of checking for the attributes. Instead of
<c:when test="#{type != 'submit'}">
I want to check tagName itself to decide how to format it. If 'input' do xxx.
2 Is this approach is still valid with jsf 1.2 other than f:ajax? If yes, can I replace with a4j:support...?
In my c:when how do I test for the tagName itself instead of checking for the attributes.
I'm not sure how this question makes sense. It sounds like that you're approaching something not entirely right. Do you maybe have copypasted exactly the same piece of code over multiple tag files? You should not do that. Make it a reuseable <ui:composition> or maybe <ui:decoration> instead which you compose/decorate in every tag file along with a fixed and unique <ui:param> value depending on the taglib file.
Is this approach is still valid with jsf 1.2 other than f:ajax? If yes, can I replace with a4j:support...?
Being able to create tag files is not necessarily specific to JSF, but to the view technology used, which is in this case Facelets. You can even do similar stuff in its predecesor JSP, see also this answer for an example: JSF 1.2 custom component from jsp:include It should work just fine in every JSF version supporting the view technology in question.
As to ajax support, it doesn't matter to the tag file what you're all doing inside the tag file. If you want and can use <a4j:support> then just do it.
Related
Is there any reason not to use c:if over the rendered attribute? When I started learning jsf the general vibe I got from the tutorials I read was that jstl tags should be forgotten. So everytime I use a jstl tag I feel like I'm doing something wrong.
However for c:if, it is executed at build time while rendered jsf attribute is executed at rendering time (explanation here). It looks like a waste to me to add something to the component tree if it's not to be rendered afterwards. Better not adding it at all using c:if, amiright?
For example on a all my pages, I've an admin menu that is included if the user is admin. I see no reason to add the menu to the tree if it's not to display it when page is rendered. So I just use c:if there. I use rendered on small parts when it's more convenient or for ajax type things.
In this beginner's JSF tuorial
section 1.1 says:
JSF UI components and their state are represented on the server with a defined life-cycle of the UI components.
But in the example that follows, I am unable to see how the state of an UI component is managed by the server? The example looks like a standard servlet jsp example minus the servlet mappings.
My other question is that in the example, we are accessing the jsp directly. Is this the standard thing to do in JSF as opposed to using servlet mappings?
First of all, if you're a beginner, I encourage you not to look at that old tutorials and find a good JSF 2.x one. JSF 2 was released in 2009 and you should consider it as the branch to learn, as it brings several advantages comparing with 1.x old versions.
JSF has its own lifecycle for any request you make from the browser which can be a GET or POST request, even an ajax based one. What you basically have to understand about JSF comparing with other frameworks is that it's stateful. In other words, you can keep a component's state from one request to another (you actually have a view state, which can be kept no matter how many requests you do, until you change the view).
Appart from that, about your last statement, in old JSF ages the servlet mapping used to be done over .*jsf suffix. It means, when you make a request for that in the browser, jsf will convert the matching jsp page and display it.
JSF 2 however introduced facelets, which are based in .xhtml view pages. It's now also possible to do the mapping as .xhtml having the source code in an .xhtml too and JSF will make the conversion. The main advantage for this is that end user will not be allowed to see the sources, as browser's request matches source page's url, so JSF servlet will always be invoked.
I'm loving the jsf 2.0 composite component setup. One other thing I love is prependId="false" on forms. Is there an equivalent that can be defined in cc:interface or cc:implementation that will prevent jsf from creating a j_id to prepend to the ids defined within the composite component?
That's not possible. Just give the component a fixed id instead letting JSF autogenerate one. The same applies on forms by the way. This way you can still select them using CSS selectors.
Or better, just give them a styleClass so that you don't need to select by ID, for the case that this aversion was actually caused by inability to select components/elements by client ID (I don't see other feasible reasons).
I have links and pictures related to these links on my page. I want to change the pictures everytime when onmouseover event occurred in the links. I want to do this in JSF.
A lot of Thanks to everyone.
You are looking specifically for JSF to do it, or you are open to other Javascript frameworks that provide a slick and easy solution on this? For example Jquery and Dojo etc may be easy to incorporate in your application and will give Rich UI effects.
On the other hand if you are looking at JSF specifically for these UI effects than probably I can try to think of some ways and let you know.
JSF isn't designed directly to do this; It's designed to give you the tools to do this yourself. In order to do this you would need to create a custom JSF component to do this and you would use Java script to do it.
You could possibly find a JSF framework that does this already (a4j, IceFaces, etc.) but this is such a simple and well documented JavaScript thing that just tossing a little Java script among your JSF is perfectly acceptable. However, if you don't want to reinvent the wheel, take a look at those other options.
Javascript solution:
Define onmouseover event on the commandLink tag calling some kind of javascript you may give link address from like onmouseover="doSomething('addressOfImage')" then in doSomething javascript method, first find the image, then set src attribute of a default image to given address.
JSF Solution:
You might want to use a4j for this.
Add a4j:support to link for onmouseover event then just rerender graphicImage component ofcourse you need to give value of graphicImage dynamically. There is an example of using a4j support below. You can add this a4j:support between your link tags for mouseonover event. Then manage everything on backing bean to handle which image to be displayed.
example
<h:graphicImage id="imageToBeRendered" value="#{myBean.imageAddress}"/>
Just google a4j if you have no idea.
I noticed that c:set does not work well used inside "include of include of include", as important notice facelets documentation does't recommend it too.
Now I am using ui:param inside ui:include, but it is a bit dispersive when no attached notes about params comes with the include, is there something other way to declare "global vars"?
This is really a matter of trying to fit old JSP programming into the JSF framework. You should be using backing beans to hold your data.
If you try to hard-code data directly into your xhtml file, you are defeating the purpose of JSF's MVC framework. If you have a specific example of what you are trying to do, I could give you a specific recommendation.