In my example, the columns were independent of the rows.
In your case, you'll have to first compute the maximum size.
Using my code, I'd do it something like this:
==============
private columnList = null;
public List getColumnList() {
if (null == columnList) {
List rowList = getRowList();
// iterate over the row list and determine the value for
maxColumnCount
columnList = createColumnListOfSize(maxColumnCount);
}
return columnList;
}
public boolean getValueFor(Object rowObject, Object columnObject) {
int columnIndex = columnObject.findIndex();
if (columnIndex >= rowObject.getColumnList.size()) return emptyObject;
else return rowObject.getColumnList(columnIndex);
}
==============
Obviously, my model isn't a direct fit to what you're doing, but the
basic logic is still the same. The first time you need it, compute
the max-size column list. Then each time a row/column item is
accessed, return the column in the row if the row has that many
elements, or return an empty object if it doesn't.
-Mike
On 11/7/05, Enrique Medina <[EMAIL PROTECTED]> wrote:
> But what should I use in my example as "value" in the <t:columns> tag? I
> mean, how can I ensure that for each row each of the child objects will be
> called? How does JSF knows it?
>
>
> 2005/11/7, Mike Kienenberger <[EMAIL PROTECTED]>:
> > My suggestion would be to adjust your column model so it always has 8
> > (or MAX) values for each row, and simply return "empty" (whatever that
> > means in your component) data for the remaining values.
> >
> > Alternatively, you could try:
> >
> > <t:columns>
> > <h:panelgroup>
> > <UIInput rendered="#{!column.empty}">
> > <h:outputText value="" rendered="#{column.empty}">
> > </h:panelgroup>
> > </t:columns>
> >
> > On 11/7/05, Enrique Medina <[EMAIL PROTECTED]> wrote:
> > > Just to clarify with a concrete example:
> > >
> > > 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?
> > > > > > > > > >
> > > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> >
>
>
