For a web application (myfaces 2.2), I need to reduce the component tree to speed up the application. How can I do this?
given:
a composite component that renders input elements due to a backing bean value
<h:dataTable value="#{myList}" var="myBean">
<h:column>
<h:inputText ... rendered="#{myBean.myValue == 1}" />
<h:selectOneMenu ... rendered="#{myBean.myValue == 2}">...</...>
<h:inputTextarea ... rendered="#{myBean.myValue == 3}" />
</h:column>
</h:dataTable>
problem:
all components appear in component tree, even when their rendered attribute is false
inputtext
selectOneMenu
inputTextarea
Is it possible to forbid JSF to build up the component tree with all three components? The restore view phase doesn't know about content of the apply request values phase, but it would be important to be able to interpret it still before.
If you want to achieve this behavior, try to use <c:if> tag instead of rendered atribute on JSF component
<c:if test="#{ myBean.myValue == 1 }">
<h:inputText .../>
</c:if>
don't forget to add namespace definition
xmlns:c="http://java.sun.com/jstl/core"
Related
I'm trying to use <c:if> to conditionally put a <h:outputLink> inside a <h:dataTable> when the state is finished.
<h:dataTable value="#{bean.items}" var="item" width="80%">
<h:column>
<f:facet name="header">
<h:outputText value="State" />
</f:facet>
<c:if test="#{item.state != 'Finish'}">
<h:outputText value="Missing value" />
</c:if>
<c:if test="#{item.state == 'Finish'}">
<h:outputLink value="myLink">
<h:outputText value="Value = #{item.state}" />
</h:outputLink>
</c:if>
</h:column>
</h:dataTable>
But this does not work, why is that and how can I fix it?
JSTL tags are evaluated during building of the view, not during rendering of the view. You can visualize it as follows: Whenever a view tree get created for the first time, all JSTL tags are executed and the result is a view with only JSF components. Whenever a view tree get rendered, all JSF components get executed and the result is HTML. So: JSF+JSTL doesn't run in sync as you'd expect from the coding. JSTL runs from top to bottom first, hands the result to JSF and then it's JSF's turn to run from top to bottom again. This may lead to unexpected results in JSF iterating components like UIData because the row data (in your particular case the #{item} object) is not available while JSTL runs.
In a nutshell: Use JSTL to control flow of JSF component tree building. Use JSF to control flow of HTML output generation.
You want to use the rendered attribute here.
<h:outputText value="Missing value" rendered="#{item.state ne 'Finish'}" />
<h:outputLink value="myLink" rendered="#{item.state eq 'Finish'}">
<h:outputText value="Value = #{item.state}" />
</h:outputLink>
See also:
JSTL in JSF2 Facelets... makes sense?
Conditionally displaying JSF components
Is it possible to have a JSF component that has ui:repeat and inside the repeat call the same component? It's because I'm building tree of question:
<cc:interface>
<cc:attribute name="questions" required="true" />
<cc:attribute name="renderQuestions" required="true" default="true" />
</cc:interface>
<cc:implementation>
<c:if test="#{cc.attrs.renderQuestions}">
<ui:repeat value="#{cc.attrs.questions}" var="q">
<p:panelGrid columns="2">
<h:outputLabel value="#{q.question}"></h:outputLabel>
<p:selectBooleanButton onLabel="#{messages['commons.yes']}"
offLabel="#{messages['commons.no']}" onIcon="ui-icon-check"
offIcon="ui-icon-close" value="#{q.ok}">
<p:ajax update="#all"></p:ajax>
</p:selectBooleanButton>
</p:panelGrid>
<cf:question renderQuestions="#{q.ok}" questions="#{q.children}" />
</ui:repeat>
</c:if>
</cc:implementation>
Currently I'm having stackoverflow?
Use a view build time tag to stop the recursion instead of a view render time tag. The component tree is built during view build time. The rendered attribute isn't evaluated during view build time, but instead during view render time. So your construct basically keeps including itself in an infinite loop. You should already know that StackOverflowError is caused by a recursion so deep that the memory stack can't handle it anymore (usually around ~1000 iterations).
Replace <h:panelGroup rendered> by a <c:if test> and it'll work as expected. The renderQuestions can by the way be simplified by omitting the check on children. The <ui:repeat> won't render anything anyway if there are no children.
If you happen to use view scoped beans in this construct and you're using Mojarra implementation, then make sure that you upgrade to at least 2.1.18, because binding a view build time tag attribute to a view scoped bean property would in older versions break the view scope.
See also:
JSTL in JSF2 Facelets... makes sense? - explains "view build time" versus "view render time"
Based on the answer of BalusC I created a solution like this.
<composite:interface>
[..]
<composite:attribute name="level" required="true" default="0"/>
</composite:interface>
<composite:implementation>
<c:if test="#{cc.attrs.level == 0}">
<a4j:repeat value="#{cc.attrs.list}" var="subList" rendered="#{cc.attrs.list != null}">
<xx:recursiveComponent list="#{subList}" id="subComponent" level="1"/>
</a4j:repeat>
</c:if>
</composite:implementation>
The level attribute is used at build time to avoid endless recursion and the renered attribute of the a4j:repeat (or ui:repeat in your case) will be evaluated at render time.
I have a problem with submitting composite components.
Most of my composite components contain both the input components and the "submit" button.
When I tried to put the button still in the same h:form but not in the same composite component, the submitted value seemed to be "lost" somewhere. And, for instance, my validators got called on original values.
Example :
<composite:interface>
<composite:attribute name="titreContext" required="true"/>
</composite:interface>
<composite:implementation>
<p:outputPanel id="selectionTitreDetailsPanel" styleClass="selectionTitreDetails">
<p:outputPanel id="selectionTitreDetailsPanelInner" rendered="#{not empty cc.attrs.titreContext.selected}">
<p:panelGrid columns="2" id="panelId">
<h:outputText id="idLabel" value="Id :"/>
<h:outputText id="id" value="#{cc.attrs.titreContext.selected.titeluid}"/>
<p:tooltip for="id" value="Identifiant unique"/>
</p:panelGrid>
<p:panelGrid columns="2" id="titelePanel">
<p:outputLabel for="selectTitele" value="Titre :"/>
<p:selectOneMenu id="selectTitele" value="#{cc.attrs.titreContext.selected.titele}" effect="fold" styleClass="fullWidth">
<f:selectItems value="#{constants.getTitelesForTypman(cc.attrs.titreContext.selected.titele.typman)}" var="titele" itemLabel="#{titele.titelelil}" itemValue="#{titele}" styleClass="fullWidth"/>
<p:column styleClass="fullWidth">#{titele.titelelil}</p:column>
</p:selectOneMenu>
</p:panelGrid>
[...]
<p:commandButton id="confirmerModifications" icon="small_edit" type="submit" value="Confirmer les modifications"
action="#{elutersEditionContext.confirmeModifsSelection}" process="mandatsTerritorial"
update="mandatsTerritorial #{cc.attrs.notifUpdates}"/>
</composite:implementation>
works.
But putting the p:commandButton out of the composite :
<h:form>
<mylib:mycomponent /*parameters *//>
<p:commandButton /*parameters*/ />
</h:form>
does not work. When I debug my validators, I can see that the modified values where not even submitted. Neither getLocalValue, getSubmittedValue nor getValue is changed.
Is there a syntax in composite component declaration to use to correct this situation ?
By the way : when I was writing my components as composite components rather than custom components, retrieving #{asen} in the backing bean just worked.
Thanks in advance.
I am using :
PrimeFaces 3.4.1
CODI 1.0.5
OpenWebBeans 1.1.6
MyFaces 2.1.9
Tomcat 7.0.32
(update) This very strange problem was caused by h:form nesting.
Very strange because h:form nesting did not perturbate the processing of the first level of composite components, but caused this strange "input lost" in nested composite.
Nesting looked like this :
<h:form>
...
<p:tabView ...>
<p:tab>
<h:form>
<my:composite ....>
</h:form>
</p:tabView>
</h:form>
You're using a relative client ID in the process attribute of the <p:commandButton>:
<p:commandButton ... process="mandatsTerritorial" />
A relative client ID is relative to the parent NamingContainer component. It will be searched as direct child of the NamingContainer component. If the child is by itself a NamingContainer, then its children would not be searched.
Composite components are by itself in fact also NamingContainer components. If the button is placed in the composite, then this will be searched as direct child of the <cc:implementation>. In your particular case, only the component with id="mandatsTerritorial" will be processed on form submit, including all of its children (note that this component is nowhere visible in the code posted so far, but I'd imagine that you omitted it for brevity).
If the button is placed in <h:form>, then this will be searched as direct child of the <h:form>. However as this is apparently been placed inside the composite (which is, as said, another NamingContainer component), it wouldn't be found and hence basically nothing would be processed. You'd need to fix the process to point to the right client ID. E.g.
<h:form>
<mylib:mycomponent id="mycomponent" />
<p:commandButton ... process="#this mycomponent:mandatsTerritorial" />
</h:form>
This way it will process itself (mandatory to invoke the action!) and the component with id="mandatsTerritorial" inside the <cc:implementation> of the composite with id="mycomponent".
As a completely different alternative, which would work just fine in this particular construct, is to remove the process attribute altogether. It defaults to #form already which will thus process the entire form.
Update as per your question update: nesting forms is invalid in HTML. Using the JSF <h:form> representation doesn't change that; you'd still end up with nested forms in HTML. The browser behaviour is unspecified as to which data would be submitted to the server. Make sure that you don't nest <h:form> in JSF as well.
I'm writing a Facelets composite component that switches between using inputText and inputSecret based on a parameter:
<composite:interface>
<composite:attribute name="myId" required="true"/>
<composite:attribute name="secret" required="false" default="false" />
</composite:interface>
<composite:implementation>
<h:inputSecret rendered="#{cc.attrs.secret}" id="#{cc.attrs.myId}" />
<h:inputText rendered="#{!cc.attrs.secret}" id="#{cc.attrs.myId}" />
</composite:implementation>
The problem is that I get the following error:
Component ID [JSF mangled id] has already been found in the view.
Use a view build time tag like JSTL <c:if> or <c:choose> instead of the JSF component's rendered attribute. View build time tags are evaluated during constructing the JSF component tree, while the rendered attribute is only evaluated during generating HTML based on the JSF component tree (and thus you still end up with both components with the same ID in the JSF component tree!).
E.g.
<c:if test="#{not cc.attrs.secret}">
<h:inputText id="input" />
</c:if>
<c:if test="#{cc.attrs.secret}">
<h:inputSecret id="input" />
</c:if>
See also:
JSTL in JSF2 Facelets... makes sense?
Unrelated to the concrete problem, the myId doesn't make sense. Just give those a fixed ID. In case the reason was the inability to reference them from outside by ajax, head to Referring composite component ID in f:ajax render.
Whether or not the component is actually rendered doesn't matter.Both components will still exist in the view's internal component tree and will require a unique id. We ran into this problem as well.
We suffixed the id with a _1 and _2 and if we need to get a hold of the id inside javaScript, we use JQuery's partial matchers.
In your case, can you not make your bean's getMyId() method return a different id based on the value of the secret property?
I'm trying to use <c:if> to conditionally put a <h:outputLink> inside a <h:dataTable> when the state is finished.
<h:dataTable value="#{bean.items}" var="item" width="80%">
<h:column>
<f:facet name="header">
<h:outputText value="State" />
</f:facet>
<c:if test="#{item.state != 'Finish'}">
<h:outputText value="Missing value" />
</c:if>
<c:if test="#{item.state == 'Finish'}">
<h:outputLink value="myLink">
<h:outputText value="Value = #{item.state}" />
</h:outputLink>
</c:if>
</h:column>
</h:dataTable>
But this does not work, why is that and how can I fix it?
JSTL tags are evaluated during building of the view, not during rendering of the view. You can visualize it as follows: Whenever a view tree get created for the first time, all JSTL tags are executed and the result is a view with only JSF components. Whenever a view tree get rendered, all JSF components get executed and the result is HTML. So: JSF+JSTL doesn't run in sync as you'd expect from the coding. JSTL runs from top to bottom first, hands the result to JSF and then it's JSF's turn to run from top to bottom again. This may lead to unexpected results in JSF iterating components like UIData because the row data (in your particular case the #{item} object) is not available while JSTL runs.
In a nutshell: Use JSTL to control flow of JSF component tree building. Use JSF to control flow of HTML output generation.
You want to use the rendered attribute here.
<h:outputText value="Missing value" rendered="#{item.state ne 'Finish'}" />
<h:outputLink value="myLink" rendered="#{item.state eq 'Finish'}">
<h:outputText value="Value = #{item.state}" />
</h:outputLink>
See also:
JSTL in JSF2 Facelets... makes sense?
Conditionally displaying JSF components