Imagine in your example of users and privileges that you want to show as rows the users' names, and as columns simply each user's privileges, but the first user (row) has 3 privileges, the second one has 5, the third one has 8 and the fourth one has 2. The maximum columns will be 8 (as of the max number of privileges per user), but not all the columns in all the rows will be printed...
2005/11/7, Enrique Medina <[EMAIL PROTECTED]>:
Great approach!
Just one comment: while your dynamic number of columns (allPrivilegeList) is known, mine is not known, and depends as commented before on the maximum size of the collections of the parent objects. For example, in your example, instead of showing all the possible values of the privileges as column headers and then showing whether the user has the privilege or not, imagine my approach: you need to have as many columns as the maximum elements in any of the collections of the parent objects that populate the data table.
Do you know what I mean?2005/11/7, Mike Kienenberger < [EMAIL PROTECTED]>:I always point out this example code I made as an example of creating
a composite component, but it also has a good example of using a
combined row&column data model.
Take a look at RowAndColumnRelationshipsBackingBean which provides the
row model and the column model. I then implement the interface in
RowAndColumnRelationshipsDataModel and can plug any number of models
into my page.
I no longer use any of the other classes since I've switched over to facelets.
Instead, I now just use this page code. I've removed some of the
decorations (like the dataScrollers), but these three files
(RowAndColumnRelationshipsBackingBean,
RowAndColumnRelationshipsDataModel, and the code below) should
demonstrate it sufficiently.
This level of indirection might be overkill for what you're doing, so
you might simply rewrite how RowAndColumnRelationshipsBackingBean
works internally.
"backingBean" is a RowAndColumnRelationshipsBackingBean configured
with another bean that implements a
RowAndColumnRelationshipsDataModel.
<x:dataTable id="datatable"
value="#{backingBean.rowDataModel}"
var="row"
preserveDataModel="false"
>
<f:facet name="footer">
<h:panelGroup>
<h:commandButton value="Update"
actionListener="#{backingBean.update}"/>
</h:panelGroup>
</f:facet>
<h:column>
<h:outputText value="#{row.rowName}"/>
</h:column>
<x:columns
value="#{backingBean.columnDataModel}"
var="column">
<f:facet name="header">
<h:outputText value="#{column.columnName}"/>
</f:facet>
<h:selectBooleanCheckbox
value="#{backingBean.relationshipValue}"/>
</x:columns>
</x:dataTable>
On 11/7/05, Enrique Medina <[EMAIL PROTECTED]> wrote:
> I understand Mike :-)
>
> So if I have a collection of parent objects, which in turn each parent
> object has a collection of other child objects, then I can show a table
> where the first column is fixed and contains vertically the list of the
> parent objects, but for each row, the columns are dynamic and can show the
> collection of child objects for each parent. Is that right?
>
> What should I use for each data model, I mean, the collection of parent
> objects to populate the main data table and the child collection of each
> parent object to populate the columns component? Would that make sense? If I
> edit all the child objects, would the getRowData from the main table return
> me a parent object with its colllection modified so I could rapidly persist
> it?
>
> Thanks for your support ;-)
>
>
> 2005/11/7, Mike Kienenberger < [EMAIL PROTECTED]>:
> > t:columns does exactly that -- it takes a collection of data and makes
> > as many columns as items in the collection.
> >
> > In fact, you can think of t:columns as a data table rotated 90 degrees.
> > The t:columns component, like dataTable is a subclass of UIData. The
> > "trick" is that when t:columns renders a "row" it uses <td> instead of
> > <tr>. It's not quite that simple, but from the perspective of an
> > end-user, it can be treated as such.
> >
> > In fact, t:columns API is a little bit confusing since getRowData()
> > really means getColumnData and getRowIndex() really means
> > getColumnIndex(). Again, that's because it's effectively a nested
> > dataTable that renders td tags instead of tr tags.
> >
> > I hope that helps!
> >
> > On 11/7/05, Enrique Medina < [EMAIL PROTECTED] > wrote:
> > > Well, maybe I have explained myself badly, but obviously the number of
> rows,
> > > although dynamic, would be fixed (i.e. the maximum of all).
> > >
> > > The main problem I have is that the data for the columns is a
> collection
> > > rather than a fixed number of properties in a class; i.e . it represents
> an
> > > object with a collection of objects inside it, and each element of the
> > > collection is the data I want to show for every column.
> > >
> > > 2005/11/7, Mike Kienenberger < [EMAIL PROTECTED]>:
> > > > I don't know of a component that generates a different number of
> > > > columns for each row. Columns allows a dynamic number of columns,
> > > > but the number is still the same for every row.
> > > >
> > > > What kind of html would you expect it to generate, since a standard
> > > > html table expects a set number of columns?
> > > >
> > > > Probably, your best bet is to go with a t:dataList which operates on
> > > > row data, but doesn't render any particular output. Then, for each
> > > > row, you can output whatever kind of html that you need.
> > > >
> > > > On 11/7/05, Enrique Medina < [EMAIL PROTECTED] > wrote:
> > > > > Hi,
> > > > >
> > > > > I want to create a special data table where the number of columns
> is
> > > > > variable in each row depending of the value of the object being
> painted.
> > > > >
> > > > > I've been looking at the HtmlColumns component, but although being
> > > dynamic,
> > > > > I can't see how I can define different number of columns for each
> row.
> > > > >
> > > > > Any idea of how to accomplish this kind of data sheet?
> > > > >
> > > >
> > >
> > >
> >
>
>
