GeeCON Prague 2014*
The moose likes JSF and the fly likes How to handle a list in JSF 2 Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login


JavaRanch » Java Forums » Java » JSF
Bookmark "How to handle a list in JSF 2" Watch "How to handle a list in JSF 2" New topic
Author

How to handle a list in JSF 2

Celinio Fernandes
Ranch Hand

Joined: Jun 28, 2003
Posts: 547

Hi,
I have what i believe is a simple question for those who are familiar with JSF.
I am not too familiar so before digging any further in the documentation i thought i'd ask here for advice.

My problem is quite simple: I want to display in a table the result of a JPQL query.
That query looks like this :
select a.name, b.title, b.age from table1 a, table2 b where a.id = b.id

So it returns a "list of lists" that looks like this:
((name1, title1, age1), (name2, title2, age2), ..., (nameN, titleN, ageN),

If i store the result of that query in an ArrayList (myList) in my Managed Bean, I can then do this in my XHTML page:



That of course does not work.
First because it displays the listing in one column only whereas there are 3 elements in each list. Secondly because item points to the list object, not an element of the list.

How do i do that in JSF 2 ? Maybe with EL ?

Thanks for helping.

SCJP 1.4, SCWCD 1.4, SCBCD 1.3, SCBCD 5
Visit my blog
Bupjae Lee
Ranch Hand

Joined: May 14, 2007
Posts: 107
You can use h:dataTable like this

kapil munjal
Ranch Hand

Joined: May 11, 2004
Posts: 298
But if there are dynamic values and I am not aware of the number of record, then how can I do this.

Regards
Kapil Kumar


Kapil Munjal
SCJP 1.4, SCWCD 1.4
Tim Holloway
Saloon Keeper

Joined: Jun 25, 2001
Posts: 16103
    
  21

The JSF tag "language" is primarily about presentation. The number one problem here is that you have a variable presentation, so it's reasonable for JSF to expect that you'll be tweaking style info and related items to allow for that. There are a lot of options there, so they didn't try to cover them all.

The typical way to handle a situation like this is to dynamically build the columns. You do this by using a control binding reference (not a data reference) and coding a method in the backing bean to construct and lay out the columns.

Any given datatable must have a fixed number of columns, so if you want to display multiple sets of data with varying numbers of columns, each dataset would require its own datatable. If the number of sets of data is also variable, then you have to build that via control binding as well, making the datatables children of the parent container to which they are bound as well as dynamically binding columns to each datatable.

Although you think this is simple, it strikes me as classic "All You Have To Do Is" syndrome. While it's certainly not rocket science, there's more work involved than it would seem based on the basic requirements.


Customer surveys are for companies who didn't pay proper attention to begin with.
 
I agree. Here's the link: http://aspose.com/file-tools
 
subject: How to handle a list in JSF 2