JSF 数据表，包含来自两个不同来源的数据

Question

I currently have a table displayed on one of my jsf pages, bound to a backing bean accounts, which unsuprisingly is a list of accounts in the system. The table loops over all accounts displaying relevant data.

Now I have the situation whereby I want to display some additional data on each row. I also want to display some performance data associated with each account. The account class itself does not contain any members relating to the performance data.

So - how can I display this data in the same table that comes from two separate sources? If I could somehow pass as a parameter the var of the current account in the datatable loop then I could use it to lookup the performance data for the client in a map, for example. I don't know how I could do that though.

All suggestions are much appreicated!

Answer 1

To do things like this I usually implement 'relationship' methods in my model objects that retrieve related objects. For example:

public class Account {
    ...
    public Client getClient() {
        // Retrieve the relevant client.
        // This could hit the database the first time it is called and then retrieve the in-memory object on successive calls.
        // Alternatively a previously instantiated Client may have been set for this Account.
    }
    ...
}

public class Client() {
    ...
    public String getName() {
        return (name);
    }
    ...
}

Then you can just do this in your JSF:

<h:outputText id="clientName" value="account.client.name" />

Answer 2

In the end I decided it was best to create a new class which contained both the account and performance data as members.

However, I did also discover a way in which you can communicate back the current row of your table. My adding an HtmlDataTable to your class, you can set the DataTable in your jsf to bind to this. Using the getRowData() of the HtmlDataTable you can get the object which represents the current row being iterated over.