I have a ui:repeat. I want it to refresh for every 5 seconds. I tried p:poll but it doesnt work. Is there any way to make this working?
<ui:repeat value="#{videoImpl.fGetAllComments()}" var="v" id="commentlist">
<div class="comment-entry"><h:outputText value="#{v.comment}"/></div>
</ui:repeat>
<p:poll update="commentlist" interval="5" />
The <ui:repeat> doesn't generate any HTML by itself. So there is no element with id="commentlist" in the HTML output and hence the JS code behind <p:poll> can't find anything to update.
Wrap it in another JSF component which renders a fullworthy HTML element, such as <h:panelGroup>, and update it instead.
<h:panelGroup id="commentlist">
<ui:repeat value="#{videoImpl.fGetAllComments()}" var="v">
<div class="comment-entry">#{v.comment}</div>
</ui:repeat>
</h:panelGroup>
<p:poll update="commentlist" interval="5" />
Related
I believe JSF 2.2 does not iterate over Maps, so c:forEach has to be used.
I have a button that adds an object in a Map via Ajax. Afterwards, it renders the list of existing objects in the Map. I logged it, and the values are inserted well. The problem is that they are not updated/refreshed correctly in the xhtml page - well, sometimes they are, sometimes they are not.
<h:commandButton action="#{myController.addValue()}" type="submit" value="Add">
<f:ajax execute="#this input1 input2" render="#form" />
</h:commandButton>
...
<h:panelGroup id="valuelist">
<!-- This does not refresh properly -->
<c:forEach items="#{myController.main.values}" var="entry">
#{entry.value.name} / #{entry.value.description}
</c:forEach>
<!-- This does refresh properly -->
<ui:repeat var="entry" value="#{myController.main.values.entrySet().toArray()}">
#{entry.value.name} / #{entry.value.description}
</ui:repeat>
</h:panelGroup>
I suppose it is something related to the JSF phases. I found a solution that uses ui:repeat, but it converts the Map to an array so I am not sure it is very efficient. How could I make the c:forEach refresh properly?
I have following code:
<ui:repeat var="class2" value="#{bean.list}" varStatus="status">
<h:form id="#{class2.name}">
<h:outputText value="#{class2.name}" />
</h:form>
</ui:repeat>
However, when I open the page, it errors as follows:
component identifier must not be a zero-length String
But it is properly printed in the <h:outputText>. How is this caused and how can I solve it?
You can use EL in the id attribute of a JSF component, but the EL variable has to be available during view build time, while the JSF component tree is to be built. However, the <ui:repeat> runs during view render time, while the HTML output is to be generated based on JSF component tree. The <ui:repeat var> is not available during view build time and #{class2.name} evaluates to null which totally explains the error you got. That it works in <h:outputText> is because it runs during view render time.
If you replace <ui:repeat> by <c:forEach>, which runs during view build time, then it'll work as you intented. The <c:forEach> will namely generate physically multiple <h:form> components in the JSF component tree which each generate individually their own HTML output (in contrary to <ui:repeat>, wherein the very same <h:form> component is been reused multiple times to generate HTML output).
<c:forEach var="class2" items="#{bean.list}" varStatus="status">
<h:form id="#{class2.name}">
<h:outputText value="#{class2.name}" />
</h:form>
</c:forEach>
However, I really wonder why you need to do that. There's usually no need to dynamically assign component IDs. JSF will already ensure the uniqueness of the ID. The below example,
<ui:repeat var="class2" value="#{bean.list}" varStatus="status">
<h:form id="form">
<h:outputText value="#{class2.name}" />
</h:form>
</ui:repeat>
will end up in multiple forms with each an unique ID, suffixed with iteration index of the <ui:repeat>. If you actually need to use #{class2.name} for some JavaScript/jQuery purposes (you did nowhere state the concrete functional requirement in the question for which you thought that this would be the right solution, so it's merely guessing), then just wrap it in a plain vanilla HTML element:
<ui:repeat var="class2" value="#{bean.list}" varStatus="status">
<div id="#{class2.name}">
<h:form id="form">
<h:outputText value="#{class2.name}" />
</h:form>
</div>
</ui:repeat>
Or set it as style class of a JSF component, which is also just selectable via a CSS selector:
<ui:repeat var="class2" value="#{bean.list}" varStatus="status">
<h:form id="form" styleClass="#{class2.name}">
<h:outputText value="#{class2.name}" />
</h:form>
</ui:repeat>
See also:
JSTL in JSF2 Facelets... makes sense?
I have following code:
<ui:repeat var="class2" value="#{bean.list}" varStatus="status">
<h:form id="#{class2.name}">
<h:outputText value="#{class2.name}" />
</h:form>
</ui:repeat>
However, when I open the page, it errors as follows:
component identifier must not be a zero-length String
But it is properly printed in the <h:outputText>. How is this caused and how can I solve it?
You can use EL in the id attribute of a JSF component, but the EL variable has to be available during view build time, while the JSF component tree is to be built. However, the <ui:repeat> runs during view render time, while the HTML output is to be generated based on JSF component tree. The <ui:repeat var> is not available during view build time and #{class2.name} evaluates to null which totally explains the error you got. That it works in <h:outputText> is because it runs during view render time.
If you replace <ui:repeat> by <c:forEach>, which runs during view build time, then it'll work as you intented. The <c:forEach> will namely generate physically multiple <h:form> components in the JSF component tree which each generate individually their own HTML output (in contrary to <ui:repeat>, wherein the very same <h:form> component is been reused multiple times to generate HTML output).
<c:forEach var="class2" items="#{bean.list}" varStatus="status">
<h:form id="#{class2.name}">
<h:outputText value="#{class2.name}" />
</h:form>
</c:forEach>
However, I really wonder why you need to do that. There's usually no need to dynamically assign component IDs. JSF will already ensure the uniqueness of the ID. The below example,
<ui:repeat var="class2" value="#{bean.list}" varStatus="status">
<h:form id="form">
<h:outputText value="#{class2.name}" />
</h:form>
</ui:repeat>
will end up in multiple forms with each an unique ID, suffixed with iteration index of the <ui:repeat>. If you actually need to use #{class2.name} for some JavaScript/jQuery purposes (you did nowhere state the concrete functional requirement in the question for which you thought that this would be the right solution, so it's merely guessing), then just wrap it in a plain vanilla HTML element:
<ui:repeat var="class2" value="#{bean.list}" varStatus="status">
<div id="#{class2.name}">
<h:form id="form">
<h:outputText value="#{class2.name}" />
</h:form>
</div>
</ui:repeat>
Or set it as style class of a JSF component, which is also just selectable via a CSS selector:
<ui:repeat var="class2" value="#{bean.list}" varStatus="status">
<h:form id="form" styleClass="#{class2.name}">
<h:outputText value="#{class2.name}" />
</h:form>
</ui:repeat>
See also:
JSTL in JSF2 Facelets... makes sense?
I have following code:
<ui:repeat var="class2" value="#{bean.list}" varStatus="status">
<h:form id="#{class2.name}">
<h:outputText value="#{class2.name}" />
</h:form>
</ui:repeat>
However, when I open the page, it errors as follows:
component identifier must not be a zero-length String
But it is properly printed in the <h:outputText>. How is this caused and how can I solve it?
You can use EL in the id attribute of a JSF component, but the EL variable has to be available during view build time, while the JSF component tree is to be built. However, the <ui:repeat> runs during view render time, while the HTML output is to be generated based on JSF component tree. The <ui:repeat var> is not available during view build time and #{class2.name} evaluates to null which totally explains the error you got. That it works in <h:outputText> is because it runs during view render time.
If you replace <ui:repeat> by <c:forEach>, which runs during view build time, then it'll work as you intented. The <c:forEach> will namely generate physically multiple <h:form> components in the JSF component tree which each generate individually their own HTML output (in contrary to <ui:repeat>, wherein the very same <h:form> component is been reused multiple times to generate HTML output).
<c:forEach var="class2" items="#{bean.list}" varStatus="status">
<h:form id="#{class2.name}">
<h:outputText value="#{class2.name}" />
</h:form>
</c:forEach>
However, I really wonder why you need to do that. There's usually no need to dynamically assign component IDs. JSF will already ensure the uniqueness of the ID. The below example,
<ui:repeat var="class2" value="#{bean.list}" varStatus="status">
<h:form id="form">
<h:outputText value="#{class2.name}" />
</h:form>
</ui:repeat>
will end up in multiple forms with each an unique ID, suffixed with iteration index of the <ui:repeat>. If you actually need to use #{class2.name} for some JavaScript/jQuery purposes (you did nowhere state the concrete functional requirement in the question for which you thought that this would be the right solution, so it's merely guessing), then just wrap it in a plain vanilla HTML element:
<ui:repeat var="class2" value="#{bean.list}" varStatus="status">
<div id="#{class2.name}">
<h:form id="form">
<h:outputText value="#{class2.name}" />
</h:form>
</div>
</ui:repeat>
Or set it as style class of a JSF component, which is also just selectable via a CSS selector:
<ui:repeat var="class2" value="#{bean.list}" varStatus="status">
<h:form id="form" styleClass="#{class2.name}">
<h:outputText value="#{class2.name}" />
</h:form>
</ui:repeat>
See also:
JSTL in JSF2 Facelets... makes sense?
<h:form>
<ui:repeat value="#{sampleManagedBean.food}" var="food">
<h:commandLink value="Name" action="#{sampleManagedBean.outcome}">
<f:param name="name" value="ssd" />
<f:param name="v" value="#{food.boy}" />
</h:commandLink>
<h2>#{food.boy}</h2>
</ui:repeat>
</h:form>
I can't get the the second <f:param> value which is set based on <ui:repeat var>. I can get only the first one which is hardcoded.
The ui:repeat is an UI component while f:param is a taghandler (like JSTL). Taghandlers run during view build time before UI components which run during view render time
(see here).
In our case it means that in the view build phase f:param knows nothing about #{food.boy}. c:forEach will be fine, but if we call some kind of ajax action to change the size of#{sampleManagedBean.food} and rerender the form, we'll not see any changes on page. Because partial rerendering (ajax) affects only UI component tree. c:forEach is somewhere between hardcoding and ui:repeat, we'll have to reload the page to see changes.
try this way,
<h:form>
<ui:repeat value="#{sampleManagedBean.food}" var="food">
<h:commandLink value="Name" action="#{sampleManagedBean.outcome}">
<f:setPropertyActionListener value="ssd" target="#{sampleManagedBean.name}" />
<f:setPropertyActionListener value="#{food.boy}" target="#{sampleManagedBean.v}" />
</h:commandLink>
</ui:repeat>
</h:form>