Hello,
Here's a really basic question (I'm just a JSF newbie) : list/detail navigation.
It's a pure JSF problem I know, but I think I can perhaps use prerender
callback to better support a list/detail scenario.
I would like to know if there's a good pattern for list / detail navigation
without impacting performance (memory, storage
or bandwidth), and with good error handling (dont load data with getters - pb
if page flush - but with callback method)?
I just wanted to use basic logic : I'll use hidden inputs in master page to
store my record primary keys, so when
I click on the link, I'll be able to load record details with this pk.
All the following 3 solutions seem to me to be awfull ones (performance
reasons).
Isn't there another one (a good one) ? Did I miss something ?
And another question : can we use prerender callbacks for this scenario ?
1. Solution 1 just use plain getters
Pb : my business logic is called twice -> show stopper.
My problem with this solution is that if I use dataTable and nested commandLink
to navigate to detail view, i.e.
<t:dataTable id="userList" var="user">
<t:column>
<h:commandLink action="#{userForm.edit}" value="#{user.username}">
<f:param name="username" value="#{user.username}"/>
</h:commandLink>
</t:column>
and my backing bean list if coded as :
public class UserList extends BasePage implements Serializable {
public List getUsers() {
List users = userManager.getUsers(null);
return users;
}
}
My business logic (userManager) will get called twice (once on RENDER_RESPONSE
phase, and another
one during postback on APPLY_REQUEST_VALUES phase).
So I'll got some performance probems.
2. Use t:saveState ou t:dataTable with preserveModel=true
I'll just have to code :
public class UserList extends BasePage implements Serializable {
private List mUsers = null;
public List getUsers() {
if (mUsers == null) {
mUsers = userManager.getUsers(null);
} else {
return mUsers;
}
}
Pros :
business logic doesn't get called twice.
Cons :
jsf context used to serialize table date (if state=client, HTML size ++, if
state=server then web session clutter).
coding : never forget the condition on getters.
3. Just store my users table on session scope
Pros : business logic doesn't get called twice.
I can use prerender to create list data.
Cons : web session clutter.
4. using flashScope
Just read sthing about trinidad flashScope, but doesn"t appear to be a good
solution, since flashScope will store all
my list data on client or session.
Thank your very much for your help
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