I am using myfaces 1.2 with trinidad and tomahawk. I have 1 view xhtml that re-displays on a claim search (the div section with the results uses EL to only display if there are results).
On a 2nd submission, it appears that some HTML components display a 2nd time. For example, i'm using a html table to render a grid. I am not using any JSF component tags to render the table, it's straightup table, tr, td.
Is there a reason why this occurs, can I not mix HTML tags in xhtml or JSF (without f:verbatim)? If so, why not? If not, any hints on what isn't properly configured? Should I use something other than xhtml?
Related
I am in the process of upgrading an old project from JSF 1.1 to JSF 2.2. Specifically, I am upgrading the JSF implementation from MyFaces 1.1 to MyFaces 2.2.12, replacing JSPs with Facelets and upgrading/replacing outdated tag libraries. I am mainly using Migrating from JSF 1.2 to JSF 2.0 as a guide.
The project used some tag library called htmLib with the namespace http://jsftutorials.net/htmLib in it's JSP pages. I can't find any documentation about this tag library anymore, neither on the jsftutorials webpage nor elsewhere, but apparently it was used to include plain HTML tags like <div> or <table> in JSP pages.
Since plain HTML tags can now be used in XML Facelets with JSF2, I am right now removing all occurences of tags from the htmLib taglib like <htm:div>...</htm:div> and replace them with plain HTML tags like <div>...</div>.
However, some of the tags used from htmLib contain the render attribute for conditional rendering, like this:
<htmLib:h4 render="someCondition">
...
</htmLib:h4>
Because plain HTML tags don't have a render attribute for this purpose, I was searching for an alternative way to conditionally render plain HTML tags and stumbled upon this answer on SO: How to conditionally render plain HTML elements like <div>s?
So, my idea is to replace a construct like the one above with something like
<ui:fragment render="someCondition">
<h4>
...
</h4>
</ui:fragment>
My questions:
Is wrapping HTML tags inside a <ui:fragment> tag with the render
attribute the recommended way to conditionally render HTML tags, or
is this method only valid and recommended for the case in the linked question?
Are there other ways to conditionally render plain HTML tags in Facelets that should be preferred?
Does the <ui:fragment> wrapping method work, no matter what kind of plain HTML is contained within it?
Can conditionally rendered <ui:fragment> blocks be nested?
There's no limitation in that. Not even for wrapping ui:fragment.
Basically:
In order just to control the inner content, with no extra HTML generation use
ui:fragment.
To generate an extra HTML span element, use h:panelGroup.
To generate an extra HTML div element, use h:panelGroup layout="block".
The HTML you have inside isn't a problem. JSF, being a server side framework, performs all the HTML building/rendering job in the server, so the JSF/facelet tags get translated to HTML before the response being sent. All the plain HTML you use inside will remain HTML.
However, beware of using tag handlers inside UI Components when migrating from 1.x. Tag handlers (ui:include, c:if, c:forEach) evaluate before the UI Components (which tipically contain rendered clauses). This has been a source of conflict in JSF 2.
I would like to know is there any way to hide/show links to certain pages by using the rendered jsf tag in conjunction with a bean method.
for eg. rendered="#{sidebarController.isGrantedAcess("Admin")} doesn't work
I started using JSF 2.0 with Facelets recently and got puzzled by new composite components knowing existing <ui:include> and other templating techniques offered by Facelets 1.x.
What is the difference between those approaches? Functionally they seem to offer about the same: <ui:param> vs <cc:attribute>, <ui:insert>+<ui:define> vs tag files, reuse of the existing templates. Is there anything besides syntax and clear interface specification in case of composite components? Could performance differ?
What is the difference between those approaches?
Facelet templates
Use Facelet templates (as in <ui:composition>, <ui:include> and <ui:decorate>) if you want to split main page layout fragments into reuseable templates. E.g. header, menu, content, footer, etc.
Examples:
How to include another XHTML in XHTML using JSF 2.0 Facelets?
What is the real conceptual difference between ui:decorate and ui:include?
How to customize h:head when using ui:composition template?
How to change head elements of a page when using ui:composition
How to ajax-refresh dynamic include content by navigation menu? (JSF SPA)
Facelet tag files
Use Facelet tag files if you want to have a reuseable group of components in order to prevent/minimize code duplication. E.g. a group of label+input+message components. The major difference with composite components is that the output of a Facelet tag file does not represent a single UIComponent and may in some circumstances be the only solution when a composite component doesn't suffice. Generally, having an <ui:include> with one or more <ui:param> which passes a managed bean property (and thus not a hardcoded value) is a signal that the include file can better be a tag file.
Examples:
How to create a custom Facelets tag?
How to make a grid of JSF composite component?
How to create a composite component for a datatable column?
Primefaces outputLabel for composite component
Composite components
Use composite components if you want to create a single and reuseable custom UIComponent with a single responsibility using pure XML. Such a composite component usually consists of a bunch of existing components and/or HTML and get physically rendered as single component and is supposed to be bound to a single bean property. E.g. a component which represents a single java.time.LocalDate property by 3 dependent <h:selectOneMenu> components representing day, month and year, or a component which combines <p:fileUpload> and <p:imageCropper> into a single <my:uploadAndCropImage> referring a single custom com.example.Image entity as property.
Examples:
Our Composite Component wiki page
The BalusC Code: Composite Component with multiple input fields
Split java.util.Date over two h:inputText fields representing hour and minute with f:convertDateTime
Select all items in Multiple SelectManyCheckBox with dynamic ids
Extending JSF commandLink component
Avoiding duplicate ids when reusing facelets compositions in the same naming container
Custom components
Use a custom component whenever the functionality cannot be achieved with Facelet tag files or composite components, because of the lack of support in the standard/available set of components. Generally when you want a high degree of control and/or customization of the decoding and/or encoding, and also to offer the endusers the possibility to relatively easily extend/override the decoding and/or encoding. Examples can be found over all place in source code of open source component libraries such as PrimeFaces and OmniFaces.
Tag handlers
When you want to control the building of the JSF component tree instead of rendering of the HTML output, then you should use a tag handler instead of a component.
Examples:
Custom Facelet component in JSF
How can I access the content of something created with <ui:define> programmatically?
Conditional render in tagfile depending on whether the attribute is specified or not
Performing a redirect, when conversion / validation associated with query parameters fails
Example projects
Here are some example projects which utilize all of above mentioned techniques.
Java EE Kickoff App (templates - includes - tagfiles - composite)
OmniFaces Showcase (templates - includes - tagfiles - composite)
Could performance differ?
Technically, the performance concern is negligible. The choice should be made based on the concrete functional requirements and the final degree of abstraction, reusability and maintainability of the implementation. Each approach has its own well definied purpose and limitations.
Composite components do however have a significant overhead during building/restoring of the view (specifically: during saving/restoring the view state). And, in older versions of Mojarra, composite components had performance issues with assigning default values, this is already fixed since 2.1.13. Also, Mojarra had a memory leak when a <cc:attribute method-signature> is used for method expressions, basically the entire component tree is re-referenced in HTTP session, this is fixed since 2.1.29 / 2.2.8. The memory leak can be bypassed in older 2.1 versions as below:
<context-param>
<param-name>com.sun.faces.serializeServerState</param-name>
<param-value>true</param-value>
</context-param>
Or in older 2.2 versions as below:
<context-param>
<param-name>javax.faces.SERIALIZE_SERVER_STATE</param-name>
<param-value>true</param-value>
</context-param>
Still, when you have relatively "a lot of" composite components, and you have javax.faces.STATE_SAVING_METHOD set to client, then the performance will be a pain. Do not abuse composite components if you merely want the basic functionality which is already possible with a simple include file or tag file. Do not use the ease of configuration (read: no *.taglib.xml file needed) as an excuse to prefer composite components over tag files.
When using Mojarra 2.2.10 or older, do not forget to disable the relatively short Facelets refresh period for production mode:
<context-param>
<param-name>javax.faces.FACELETS_REFRESH_PERIOD</param-name>
<param-value>-1</param-value>
</context-param>
Do not use this setting for development, otherwise you've to restart the whole server to get changes in Facelets files to be reflected! Mojarra 2.2.11 and newer, and MyFaces already defaults to -1 when javax.faces.PROJECT_STAGE is not set to Development.
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)
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