JSF component disappears after binding - jsf

I defined a custom component and tried to use binding as the following:
<ui:composition ...>
<div>
<f:subview>
<a4j:outputPanel>
<h:commandButton id="t1" value="test!" />
...
</a4j:outputPanel>
</f:subview>
</div>
</ui:composition>
This component works properly until I added a binding attribute like this:
<h:commandButton id="t1" binding="#{foo}" value="test!" onclick="alert('I am #{id:cid(foo)}'); return false;" />
This component doesn't show up, and I can't find the corresponding piece of code for this button.
Anyone knows a fix?

yes, it is used multiple times
There's the cause. The binding should refer an unique reference for the component. Right now you've physically multiple components referring to one and same reference.
I'm not sure what's the concrete functional requirement is, but more than often this approach is unnecessary when you're already inside the JavaScript context. The particular example can then also just be solved as follows:
<h:commandButton id="t1" value="test!" onclick="alert('I am ' + id); return false;" />
The ID of the generated HTML element itself is namely exactly the same as JSF component client ID.

Related

Send parameter to request on every action for composite component

I have a composite component, which has an id I would like to send as a parameter when executing one of many posiible actions inside the composite component. I know I can use something like;
<h:form id="testForm">
<p:commandButton value="#{testReqBean.label}"
actionListener="#{testReqBean.perform()}"
process="#this or #form" update="#form" ajax="true" >
<f:param value="#{cc.attrs.id}" name="CC-Id" />
</p:commandButton>
</h:form>
now, imagine I have many forms or buttons with specific actions inside the composite component... is there a way to define the parameter I want to send in the request just once ? I mean not adding an f:param inside each form/button (depending on the process #form or #this) but one for the whole composite component?
Thanks in advance!
Maybe one solution would be to use viewparam but this only works if you can add a request parameter.
<f:metadata>
<f:viewParam value="#{your_bean.your_property_name}" name="request_param"/>
</f:metadata>
The only problem here is that whoever implements your composite component would have to set the above when needed, but it still an abstraction to this problem of having to set the same property for all components in same page.
I gather that the <h:form> is enclosed in the composite component itself.
Just use a plain HTML hidden input field.
<h:form>
<input type="hidden" name="CC-Id" value="#{cc.attrs.id}" />
...
<p:commandButton />
<p:commandButton />
<p:commandButton />
...
</h:form>
Unrelated to the concrete problem, having an entire form in a composite is kind of strange. This is then food for read: When to use <ui:include>, tag files, composite components and/or custom components?

How do PrimeFaces Selectors as in update="#(.myClass)" work?

I don't understand how PrimeFaces selectors (PFS) work.
<h:outputText value="#{bean.text1}" styleClass="myClass" />
<p:commandButton update="#(.myClass)" />
I can use it. And I think it's a fantastic tool although it doesn't function always for me. The .myClass is client side jQuery selector. How does JSF on server side know what to update?
I can understand how normal JSF ID selectors work.
<h:outputText value="#{bean.text1}" id="textId" />
<p:commandButton update="textId" />
The textId references an ID of component in the component tree as defined in XHTML file in server side. So I can understand how JSF finds the right component.
But if you are using primefaces selectors, the client side jQuery selectors are used. How does JSF know which component has to be updated? Sometimes I have problems with PFS. It doesn't seem to function always for me. Is there something what you should keep in mind if you are using PFS?
You probably already know that PrimeFaces is using jQuery under the covers. PrimeFaces Selectors are based on jQuery. Anything which you specify in #(...) will be used as jQuery selector on the current HTML DOM tree. For any found HTML element, which has an ID, exactly this ID will ultimately be used in the update.
Basically, for a update="#(.myclass)", PrimeFaces will under the covers roughly do this:
var $elements = $(".myclass");
var clientIds = [];
$.each($elements, function(index, element) {
if (element.id) {
clientIds.push(":" + element.id);
}
});
var newUpdate = clientIds.join(" "); // This will be used as `update` instead.
So, in case of e.g.
<h:form id="formId">
<h:outputText id="output1" styleClass="myclass" ... />
<h:outputText styleClass="myclass" ... />
<h:outputText id="output3" styleClass="myclass" ... />
</h:form>
this command button update
<p:commandButton ... update="#(.myclass)" />
will end up with exactly the same effect as
<p:commandButton ... update=":formId:output1 :formId:output3" />
Note that this also works for autogenerated IDs. I.e. the <h:form id> is not mandatory.
Sometimes I have a problems with PFS. Is there something what you are should keep in mind if you are using PFS ?
It can happen that you selected "too much" (e.g. #(form) doesn't select current form, but all forms, exactly like $("form") in jQuery!), or that you actually selected nothing (when the desired HTML DOM element has actually no ID). Investigating element IDs in the HTML DOM tree and the request payload in the HTTP traffic monitor the should give clues.
The desired elements in the HTML DOM tree must have an (autogenerated) ID. The javax.faces.partial.render request parameter in the HTTP traffic monitor must contain the right client IDs. The element's rendered attribute in the JSF component tree must evaluate true during update. Etcetera.
In your particular example, the <h:outputText> won't end up in the generated HTML output with any ID. Assigning it an id should solve your problem with updating it.
So, this example won't work
<h:form>
<h:outputText value="#{bean.text1}" styleClass="myClass" />
<p:commandButton value="Update" update="#(.myClass)" />
</h:form>
but this example will work (note that assigning the form an ID is not necessary):
<h:form>
<h:outputText id="myText" value="#{bean.text1}" styleClass="myClass" />
<p:commandButton value="Update" update="#(.myClass)" />
</h:form>

Javascript error in XHTML page in JSF 2

I have the following code in an xhtml page in JSF 2. But when the page loads I get an javascript error that
document.getElementById("country") is null or not an object.
Why is this happening?
<h:form>
<h:panelGrid columns="2">
Selected country locale :
<h:inputText id="country" value="#{country.localeCode}" size="20" />
Select a country {method binding}:
<h:selectOneMenu value="#{country.localeCode}" onchange="submit()"
valueChangeListener="#{country.countryLocaleCodeChanged}">
<f:selectItems value="#{country.countryInMap}" />
</h:selectOneMenu>
<script>
alert("hi");
document.getElementById("country").disabled=true;
</script>
</h:panelGrid>
</h:form>
It's not finding your component. Since your <h:inputText> is inside of an <h:form> the id will have the following pattern
formName:componentName. Since you did not specify an id for <h:form>, JSF will generate one for you. That's why you are seeing j_id1926454887_72d35e53:country where j_id1926454887_72d35e53 is the form id. If you want to deal with simpler id, then you should add an id value to your <h:form>. For example
<h:form id="form">
<h:inputText id="country" value="#{country.localeCode}" size="20" />
</h:form>
The id for <h:inputText> will now be form:country.
Even simpler, you could simply add prependId = "false" to your form
<h:form prependId="false">
and now your id for <h:inputText> will simply be country.
How can I get this id dynamically?
I'm going to modify your code slightly to achieve what you want (I'm thinking that you want to disable the input based on a specific event). Consider this simpler example
<h:form>
<h:inputText id="country" value="#{country.localeCode}" size="20" onclick="disableInputText(this.form)" />
</h:form>
Here I'm attaching a javascript function to an HTML DOM Event handler. In this case, I want the input to be disabled when I click on it (hence onclick). I'm also passing the form as a reference in the function. Then, define your Javascript like this.
<script>
function disableInputText(form) {
form[form.id + ":country"].disabled = true;
}
</script>
We simply grab the input in the javascript with the corresponding id via the object form and set its disabled attribute to true. (You can sort of view the form object as Map).
Also check the link below for more attributes of <h:inputText> and the different handlers you can use (the ones with on as prefix).
inputText Tag Attribute.
Also, check out the answer with the most votes to get a bigger picture on how ids are generated and other ways on how they can be determined.
How can I know the id of a JSF component so I can use in Javascript
It's seems to be a naming issue. the id of the field is not rendered as country.
i found a question that seems relevant. Composite components & ID

Conditional rendering in JSF [duplicate]

This question already has an answer here:
Ajax update/render does not work on a component which has rendered attribute
(1 answer)
Closed 7 years ago.
Hello I have this code to conditionally render components in my page:
<h:commandButton action="#{Bean.method()}" value="Submit">
<f:ajax execute="something" render="one two" />
</h:commandButton>
<p><h:outputFormat rendered="#{Bean.answer=='one'}" id="one" value="#{messages.one}"/></p>
<p><h:outputFormat rendered="#{Bean.answer=='two'}" id="two" value="#{messages.two}"/></p>
It gets the answer and renders the component but in order to see it on my page, I need to refresh the page. How can I fix this problem? Any suggestions?
The JSF component's rendered attribute is a server-side setting which controls whether JSF should generate the desired HTML or not.
The <f:ajax> tag's render attribute should point to a (relative) client ID of the JSF-generated HTML element which JavaScript can grab by document.getElementById() from HTML DOM tree in order to replace its contents on complete of the ajax request.
However, since you're specifying the client ID of a HTML element which is never rendered by JSF (due to rendered being false), JavaScript can't find it in the HTML DOM tree.
You need to wrap it in a container component which is always rendered and thus always available in the HTML DOM tree.
<h:commandButton action="#{Bean.method()}" value="Submit">
<f:ajax execute="something" render="messages" />
</h:commandButton>
<p>
<h:panelGroup id="messages">
<h:outputFormat rendered="#{Bean.answer=='one'}" value="#{messages.one}"/>
<h:outputFormat rendered="#{Bean.answer=='two'}" value="#{messages.two}"/>
</h:panelGroup>
</p>
Unrelated to the concrete problem, you've there a possible design mistake. Why would you not just create a #{Bean.message} property which you set with the desired message in the action method instead, so that you can just use:
<h:commandButton action="#{Bean.method()}" value="Submit">
<f:ajax execute="something" render="message" />
</h:commandButton>
<p>
<h:outputFormat id="message" value="#{Bean.message}" />
</p>
I know it's not the central point of the question, but as I had this problem many times in the past, I just post it here to help others who are in need.
For those who uses PrimeFaces there's a component in PrimeFaces Extension called Switch.
Sometimes you need to display different outputs or components depending on a value. Usually you can achieve this by using the ui:fragment tag. With the pe:switch util tag you won't have to declare ui:fragment tags, with different checks like ui:fragment rendered="#{!empty someController.value}", anymore.
style="visibility: #{questionchoose.show==false ? 'hidden' : 'visible'}"

How to do client side updates in JSF 2.0

I'd like to do client side component updates. Example: disable a button when a checkbox is clicked:
<h:selectBooleanCheckbox value="true" onchange="button.disabled=true" />
<h:commandButton id="button" value="Save" />
The above doesn't work. Is there a way to do this declaratively in JSF?
It doesn't work because the JSF component ID is not necessarily the same as the generated HTML ID. JSF composes the HTML element ID and form element name based on the ID's of all UINamingContainer components in the tree -if any. The UIForm component is one of them. Rightclick the page in webbrowser and choose View Source. See and learn.
There are two ways to solve this problem:
Set prependId attribtue of <h:form> to false.
<h:form prependId="false">
<h:selectBooleanCheckbox value="true" onclick="button.disabled=true" />
<h:commandButton id="button" value="Save" />
</h:form>
Note that I'd rather use onclick="button.disabled=!checked" instead. The onchange is only fired when the input element loses focus and that is non-intuitive in case of checkboxes and radiobuttons. Also, you'd like to turn it back on when the checkbox is checked again, right?
Give the <h:form> a fixed ID so that you know how the generated form element name look like:
<h:form id="form">
<h:selectBooleanCheckbox value="true" onclick="form['form:button'].disabled=true" />
<h:commandButton id="button" value="Save" />
</h:form>
The brace notation is mandatory because the : is an illegal identifier character and just onclick="form:button.disabled=true" won't work. Also here, I'd rather use onclick="form['form:button'].disabled=!checked instead.
The same problem applies on document.getElementById() as well. So simply replacing button by document.getElementById('button') alone won't fix the problem.
simply use javascript
document.getElementById("buttonId").disabled="true";
Check this

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