I am new to JSF. I have 3 cascading SelectOneMenu i.e Countries, States and Cities. The functionlity is when country is selected corressponding states are populated and when state is selected cities are populated.
I am using a4j:support tag for implementing it. My managed bean is in request scope and is spring managed beans.
I have written ActionListener for CountriesChanged(), StatesChanged() and CitiesChanged().
In my application when one selects countries, action event is fired and states are populated.
However, when one changes states, it throws "Validation Error : Value is not valid"
It would be helpful if somebody guides me proper direction.
You need to prepare exactly the same list of states during the form submit request as it was during the form display request. JSF will namely re-validate the submitted value against the list of available items. In case of a request scoped bean, you have to prepare it in the bean's (post)constructor. Another way is to put the bean in the new JSF 2.0 view scope so that the bean don't get recreated whenever you submit the form against the same view.
Related
I am new at JavaServer Faces (JSF).
I have a list of cars and after pressing the commandButton of my first page I want to show the list in the other page (the backing beans are RequestScoped).
I have seen examples where you can only pass String values.
if you have list of cars, it means you have data table or some another list which is coming from managed beans. if you want show whole list in the next page, you need just call the same list from next page.
if you want pass only one row /object, you should pass row/item id via f:param , in the next page from another managed bean you should handle id and call from database getItemById(id) and in the page show item.
I have a primitive view: a form containing a validatable text input component and a command button. The input value is pointing to a session-scoped backing bean.
I open the page, enter an invalid value and submit the form: after the postback, a validation error is appearing and the input component is displaying the submitted value which did not pass validation. The model value in my session-scoped bean is left intact, as expected.
Ok, now I open another tab in the browser and open the same page. To my surprise, the input component is displaying the submitted value from the first tab. I've been supposing the view state to be new at another GET request and the plain model value from my session-scoped bean to be shown instead.
If I use a view-scoped bean instead of a session-scoped one the model value is being rendered for the input component in the second tab, not the submitted value from the first tab.
Is the submitted value not the part of the view state and kept somehow along with the model? Or is its scope tuned up in some smart way depending on the referenced bean's scope?
Sorry in advance if this question is stupid but I will be very grateful for removing my misunderstanding.
I have a sample use case: I have an edit page that use GET parameter "id".
eg. edit?id=1
This edit page is backed by a ViewAccessScoped (CODI) Bean.
In this edit page, I have a datatable with links that link to the same "edit" page, but with another id. (eg. edit?id=2)
<h:link value="#{mecaPart.id}" outcome="edit" target="_blank">
<f:param name="id" value="#{mecaPart.id}" />
</h:link>
The problem, is that the window open correctly, but it is the same bean that is used! And so I am editing the same part...
I have placed a log in #PostConstruct, and it is the same bean reference that is called multiple times. (even with the new ID!)
My question, how can I tell JSF to create a new ViewAccessScoped backing bean when I click the link, and not re-use the actually used one?
Finally, I discovered that #ViewScoped CODI bean did not preserved the backing bean from page refresh. So, I have to use ViewAccessScoped.
According to Gerhard Petracek: http://os890.blogspot.fr/2011/08/scopes-view-scope-vs-view-access-scope.html
the view-scope of jsf2+ is bound to a concrete jsf page. that means: as soon as you navigate to a different page, the state gets lost. that's better than nothing, but not useful for a lot of use-cases. the main use-case which needs it are ajax-requests on a page and the data used by them aren't needed on other pages, but it's pretty easy to break it e.g. with a browser-refresh on a page which stores the data in a view-scoped bean and has no form with input components. (in a previous blog post i described how to use the infrastructure provided by codi to create a session based view-scope to overcome such disadvantages cause by storing view scoped beans as part of the tree-state.)
like with the view-scope view-access-scoped beans are available on a page, but they also exist for the next page. that means: they are forwarded to the next page and get destroyed autom. if they don't get used during the first request of the next page. that's e.g. useful for wizards. if you have a wizard page which doesn't use the bean or you have to support the possibility to interrupt a wizard, you can use the grouped-conversation scope (and even the window-scope) provided by codi. however, due to the powerful api of codi you can also destroy the scope manually at any time (if needed).
So, to solve the problem of opening a new tab with another "ID", I had to set "CODI Client Side WindowHandler", according to the CODI Wiki.
https://cwiki.apache.org/confluence/display/EXTCDI/JSF+WindowHandler
So I added:
<alternatives>
<class>org.apache.myfaces.extensions.cdi.jsf.impl.scope.conversation.ClientSideWindowHandler</class>
</alternatives>
To the file beans.xml, and I used #ViewAccessScoped. Everything is working smoothly now.
You can use #ViewScoped which also works in CODI
Please note: This question is about CDI scopes as we are using CDI scopes in the app and not JSF scopes.
1) Controller Bean (TestController.java) which is in RequestScoped (enterprise context) is called index_cut.xhtml, when we come for first time on this page.
2) On button “Load”, we load the following method to populate the sapFinancialPeriodList which works fine and displays the data
3) After changing the content on the page and submitting, the sapFinancialPeriodList appears as NULL in the following method –
Any suggestions?
Your bean is request scoped and you're loading the data model on action only instead of on (post)construction. When the HTTP response after the action which loaded the data is finished, then the bean is garbaged. The subsequent request would get a brand new instance of the bean with all properties set to default. However, as the same data model isn't been preserved during (post)construct, it remains empty.
In JSF2 you'd solve this with using #ViewScoped. This way the bean will live as long as you're interacting with the same view by postbacks (which return null or void).
In CDI you'd need to solve this using #ConversationScoped, which in turn requires some additional #Inject Conversation boilerplate, complete with begin() and end() calls at the right moments. For a concrete example, see also What scope to use in JSF 2.0 for Wizard pattern?.
An alternative is to pass the parameters responsible for creating the data model to the subsequent request via <f:param> in the command link/button as follows
<h:commandButton value="save" ...>
<f:param name="period" value="#{bean.period}" />
</h:commandButton>
and then recreate exactly the same data model in (post)constructor of the request scoped bean as follows
String period = FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap().get("period");
List<SapFinancialPeriod> sapFinancialPeriodList = someservice.list(period);
(the above is by the way nicer to solve with #ManagedProperty if you were using standard JSF; as far as I know CDI doesn't have an annotation which enables you to set a HTTP request parameter as a bean property)
See also:
How to choose the right bean scope?
Unrelated to the concrete problem, the upcoming JSF 2.2 solves this functional requirement in a nicer way using the new "Faces Flow" feature with the new #FlowScoped annotation and the new xmlns:j="http://java.sun.com/jsf/flow" tags.
I am using JSF 2.0/CDI and PrimeFaces 2.2.1 for a number of CRUD forms that let the user view or update the attributes of an existing entity by clicking on a link in a datatable, where the identifier of the entity is passed to the CRUD form as a View Parameter. I display the entity's ID (often just an integer) on the CRUD form in a PrimeFaces InputText field with the readonly attribute set to true (since I can't let them change it), so the user knows which entity they're editing. The backing bean of the CRUD form is RequestScoped, which works fine except when validation fails. In that case, the value of the View Parameter is lost, so a 0 is displayed in the entity ID field on validation failure.
I am able to maintain the actual entity ID in a hidden field so it's available to update the database once validation succeeds, but it's rather maddening that I've not been able to find a way to maintain the value in a visible field of some sort after a validation failure. Ideally the InputText field would retain its functionality as an inputted and validated field even with its readonly (or disabled) attribute set to true, which would let me forgo the hidden field entirely. But it doesn't appear that I can make it work that way. Any suggestions besides making the backing bean ConversationScoped, which I'd prefer to avoid?
Actually, after stating what I'm looking for a little differently in a Google search I found a novel suggestion at the link below that seems to work cleanly. Instead of making the entity ID field readonly or disabled, I leave it enabled but blur it as soon as it receives focus. I'm able to get rid of the hidden field, the user can't change the value and it survives a validation failure.
<p:inputText id="entid" value="#{RequestBean.entityID}" onfocus="blur();" />
http://www.codingforums.com/archive/index.php/t-1738.html