I am little confused about my radio button list in JSF and how it reacts to stuff and I didn't find much help online. Below is the declaration of my radio button list and the method which should be called in case the value of the radio changes:
<h:selectOneRadio value="#{AddExpense.selectedTypeExp}" layout="pageDirection"
valueChangeListener="#{AddExpense.changed}">
<f:selectItems value="#{AddExpense.typeExpList}"/>
<a:support event="onclick" action="#{AddExpense.typeExpChanged}" immediate="true"/>
</h:selectOneRadio>
When I choose a different value, only the typeExpChanged is called, but the AddExpense.changed method is not called. I think I'm confusing something here, not sure how the changeListener should react... Below is my very simple test method which should be called:
public void changed(ValueChangeEvent event){
System.out.println("In changed event method: "+event.getNewValue());
}
Should I change something in the <a:support> ?
The reason I have both event and valueChangeListener is because I wanted to test what reacts to my changing the selection. I just need a method to be called with a parameter which tells me the selected value, so I can load something else.
Thanks in advance!
The valueChangeListener is not a client side event listener. It's a server side event listener. It does not generate any line of HTML/JS/Ajax code and it is triggered by JSF itself when you submit the form to the server and the submitted value is different from the initial model value.
Just keep using Ajax4jsf <a4j:support>, it's perfectly fine for your particular functional requirement.
Related
I have some problems with calling a bean method when clicking on Label.
When page is loading or refreshing click handler function pokus() is called, but when the label is clicked it isn't.
Part of my web page:
<h:form id="pokus">
<p:outputLabel id="pokus2" value="klikni" onclick="#pozadavkyBean.pokus(5)}"/>
</h:form>
and a method in bean:
public void pokus(int i){
System.out.printf("kliknuto sloupec:%d",i);
}
I've also tried it with:
<p:ajax event="click" listener="....
with the same result - method called on loading/refreshing but not when clicking
also tried others events: mousedown, mouseup, .... with same result
using PrimeFaces 5.0
If you will check official document of Primeface regarding Tag outputLabel.You can easily get attribute onclick used for
Client side callback to execute when component is clicked.
But here you are trying to run Managed bean method directly from onclick attribute while onclick used to call JavaScript functions.
As #Mahendran Ayyarsamy Kandiar mentioned and its simple thing outputLabel is not used to call any bean method. Its Just Simply used to show something in the page.In mean time for your requirement you can use CommandButton,CommandLink or some other component but its all depend upon your requirment etc.
I'm working on building a web page and notice now that I have to press the command button twice. Any command button has the same problem, so I figured I would add and action listener on one of them to see if I could see something.
<h:form id="formP">
<p:commandButton id="temp" value="photos" actionListener="#{viewBacking.debugBreakpoint()}" action="userPhoto" />
</h:form>
The backing bean has
public void debugBreakpoint() {
int i = 0;
i++;
}
Unfortunately, this does help. It hits my breakpoint only after the second press. I suspect that some field somewhere isn't passing validation but I would like some method of detecting what exactly is going wrong - why do I need the second push? Is there some option I can turn on in Glassfish, or something else where I can look at a dump of debug information? I can ignore the dump until everything is stable and then see what exactly is happening when I press the button for the first time.
Is there any such tool which I can use?
That can happen when a parent component of the given <h:form> has been rendered/updated by another command button/link with <f:ajax>. The given form will then lose its view state which it would only get back after submitting the form for the first time. Any subsequent submits will then work the usual way. This is caused by a bug in JSF JS API as descibred in JSF issue 790 which is fixed in the upcoming JSF 2.2.
You need to fix the another command button/link with <f:ajax> to explicitly include the client ID of the given <h:form> in the render.
<f:ajax render=":somePanel :formP" />
Another way is to replace this <f:ajax> by a PrimeFaces <p:commandLink> or <p:commandButton> so that you don't need to explicitly include the client ID of all the forms. PrimeFaces's own JS API has namely already incorporated this fix.
add event="onclick" in your p:commandbutton
I guess that will sort it out.
or you can add this ajax="false" property in your commandButton
<p:commandButton ajax="false" action="#{userController.create}" value="#{bundle.CreateUserSaveLink}"></p:commandButton>
I ran into the same issue. The solution was simple, instead of having both an actionListener and an action, just convert the actionListener method to return a string to where you want to navigate to and use it as the method for the action (and don't have an actionListener).
In simple terms: only use an action (do not use an actionListener on a commandButton that is submitting a form).
Please check your binding with bean.
bean fields should be String or non primitive.
I have the following situation:
after clicking a button, some business logic is done and after it is done, a new tab with a report should be visible.
<p:commandButton value="this button" update="growlMain"
actionListener="#{myBean.businesslogic}"
onstart="ajaxDialog.show();"
oncomplete="ajaxDialog.hide();"
onsuccess="window.open('./report.jsp', '_newtab');" />
This does not work :(
If the business logic only lasts some milliseconds, the following works:
<p:commandButton value="this button" update="growlMain"
actionListener="#{myBean.fastbusinesslogic}"
onclick="window.open('./report.jsp', '_newtab');" />
the onclick opens a new tab, also things like onstart but it doesn't work with onsuccess or oncomplete. Why? And is there a solution for business logic that lasts some seconds?
onclick is called before the ajax request is even created (pure client side) while oncomplete and onsuccess are executed after the server responded to the ajax request. So, if you need to execute some business logic before showing a dialog, for example, you want to go with oncomplete. That's what I always use.
You can also condition your javascript inside oncomplete to perform only if there's no validation errors. Intuitively I think onsuccess would behave like that and only execute when there's no validation errors, but that's not how it goes. I don't really know the difference between them. I assume there's a way to flag success=false in the backing beans, but I couldn't really find it in the documentation.
If you want to check for validation in your oncomplete attribute, this is how you'd do:
oncomplete="if (!args.validationFailed){someDialog.hide()}"
In this case, you would only close the dialog if the fields are properly validated. You can actually inject parameters from the backing bean and use them in the javascript after the request has been served. In your backing bean you can do something like this:
RequestContext.getCurrentInstance().addCallbackParam("showDialog", false);
And you can access the parameter like this in your incomplete attribute:
oncomplete="if (args && args.showDialog){someDialog.show()}else{ alert('the bean didnt let me open the dialog')}"
Anyway, I hope that helps.
I have noticed that onsuccess for PrimeFaces command button does not work. The oncomplete however works and does the needful even if there is an error , such as in my case shows a success dialog even if there is an error in my business logic. Tried to use onsuccess but doesn't work.
You could try oncomplete as below:
<p:commandButton value="this button" update="growlMain"
actionListener="#{myBean.businesslogic}"
onstart="ajaxDialog.show();"
oncomplete="ajaxDialog.hide(); window.open('./report.jsp', '_newtab');"/>
You can see the difference here:
Primefaces and ajax onsuccess event
or with onsuccess you can do something before full loading DOM
My problem is that when the user unchecks everything (leaving 0 checkboxes checked) JSF does not fire the valueChangeListener.
I appreciate any help, thanks.
JSPX:
<h:selectManyCheckbox
value="#{EME01.selectedMaterials}"
valueChangeListener="#{EME01.materialsValueChangeListener}"
onchange="submit();">
<f:selectItems value="#{EME01.materials}" />
</h:selectManyCheckbox>
Backing bean (EME01):
public void materialsValueChangeListener(ValueChangeEvent e) {
System.out.println("hello");
}
For checkboxes (and radio buttons) you're rather interested in click event than the change event.
onclick="submit()"
Unrelated to the concrete problem, consider using Ajax for this as it's pretty bad user experience to submit the entire form and have a flash of content on every change/click of the checkbox. If you're already on JSF2 for example, use <f:ajax> instead.
HI,
Please see the following code:
<h:selectOneMenu id="countries" value="#{countryBean.selectedCountry}" onchange="submit()
valueChangeListener="#{countryBean.changeCountry}">
<f:selectItems value="#{countryBean.countries }" />
</h:selectOneMenu>
Backing Bean
public void changeCountry(ValueChangeEvent event){
String newValue = (String)event.getNewValue();
String oldValue = (String)event.getOldValue();
System.out.println("New Value : " + newValue);
System.out.println("Old Value : " + oldValue);
if ("1".equals(newValue)){
this.countries = new ArrayList<SelectItem>();
this.cities.add(new SelectItem("1","Delhi"));
this.cities.add(new SelectItem("2","Mumbai"));
}
if ("2".equals(newValue)){
this.cities = new ArrayList<SelectItem>();
this.cities.add(new SelectItem("1","Mossco"));
}
}
Please let me know if the implementation is correct. It is working fine.
My questions are:
What is the advantage of adding the f:valueChangeListener tag inside the h:selectOneMenu tag. I have used the normal attribute valueChangeListener="#{countryBean.changeCountry}".
Is it necessary to use onchange="submit() this code to change the values.
What is difference between writing the custom listeners by implementing the ActionListener interface and just using the attribute in the UIComponent tags (action="methodName").
Please explain me.
The ValueChangeListener will only be called when the form is submitted, not when the value of the input is changed. Thus, if you want to run this listener when the value is modified, you have two solutions:
Submit your form when the onchange event is fired (this is what you did in your code);
Use an Ajax call instead, by using some dedicated components (already integrated in JSF2, with <f:ajax>, or third-parties libraries such as Richfaces, Primefaces...).
Here is an example with Richfaces:
<h:selectOneMenu id="countries" value="#{countryBean.selectedCountry}" valueChangeListener="#{countryBean.changeCountry}">
<a4j:support event="onchange" .../>
<f:selectItems value="#{countryBean.countries }" />
</h:selectOneMenu>
Regarding the code of your listener, it seems correct, but why question is why do you need a ValueChangeListener here? Indeed, this listener is usefull when you want to track a modification of a value. That's why the ValueChangeEvent provides both getOldValue() and getNewValue() methods.
In your code, you do not care about the old value, so basically, you could "simply" do an action instead of a valueChangeListener (ex. with Richfaces):
<h:selectOneMenu id="countries" value="#{countryBean.selectedCountry}">
<a4j:support event="onchange" actionListener="#{countryBean.changeCountry}"/>
<f:selectItems value="#{countryBean.countries }" />
</h:selectOneMenu>
Finally, regarding the difference between the valueChangeListener attribute and <f:valueChangeListener> is that the first binds a Java method (#{myBean.myMethod}), while the second binds a Java class (type="com.foo.MyListenerClass") which implements the ValueChangeListener interface. So the second one could be more generic than the first one...
Romaintaz already pointed out the most, I just wanted to get straight on your concrete questions:
What is the advantage of adding the f:valueChangeListener tag inside the h:selectOneMenu tag. I have used the normal attribute valueChangeListener="#{countryBean.changeCountry}".
As Romaintaz said, the attribute points to a method and the f: tag points to a class. Another advantage is that you can have multiple of them, whenever that is necessary.
Is it necessary to use onchange="submit() this code to change the values.
That Javascript doesn't change the values. That Javascript submits the entire form without the need to pressing the submit button yourself, whenever the value has been changed by the enduser. No, that is not necessary. You can also just remove it and expect that the enduser presses the submit button himself. Once again, that JavaScript is not part of JSF.
What is difference between writing the custom listeners by implementing the ActionListener interface and just using the attribute in the UIComponent tags (action="methodName").
This question is already asked before: difference between action and actionlistener.
The solution from romaintaz of calling an action instead of valueChangeListener is also great because in the case of "change" event the action is called after the model is updated (allowing for a DB update for example) while the valueChangeListener is called before....