ASP.NET DataList - defining "columns/rows" when repeating horizontal and using flow layout

Question

Here is my DataList:

<asp:DataList id="DataList" Visible="false" RepeatDirection="Horizontal" Width="100%" HorizontalAlign="Justify" RepeatLayout="Flow" runat="server">
        [Contents Removed]
</asp:DataList>

This generates markup that has each item wrapped in a span. From there, I'd like to break each of these spans out into rows of three columns. Ideally I would like something like this:

<div>
 <span>Item 1</span>
 <span>Item 2</span>
 <span>Item 3</span>
</div>
<div>
 <span>Item 4</span>
 <span>Item 5</span>
 <span>Item 6</span>
</div>
[etc]

The closest I can get to this is to set RepeatColumns to "3" and then a <br> is inserted after every three items in the DataList.

 <span>Item 1</span>
 <span>Item 2</span>
 <span>Item 3</span>
<br>
 <span>Item 4</span>
 <span>Item 5</span>
 <span>Item 6</span>
<br>

This gets me kind of close, but really doesn't do the trick - I still can't control the layout the way I'd like to be able to.

Can anyone suggest a way to make this better? If I could implement the above example - that would be perfect, however I'd accept a less elegant solution as well - as long as its more flexible than <br> (such as inserting a <span class="clear"></span> instead of <br>).

Solution 1

If you really needed to use a datalist for some reason instead of implementing this as a repeater, you can try doing something like this:

<asp:DataList ID="dataList" runat="server" RepeatDirection="Horizontal" Width="100%" HorizontalAlign="Justify" RepeatLayout="Flow" OnItemDataBound="dataList_ItemDataBound">
    <HeaderTemplate>
        <div>
    </HeaderTemplate>
    <SeparatorTemplate>
        </div><div>
    </SeparatorTemplate>
    <ItemTemplate>
        <%# Container.DataItem %></ItemTemplate>
    <FooterTemplate>
        </div></FooterTemplate>
</asp:DataList>

---

protected void dataList_ItemDataBound(object sender, DataListItemEventArgs e) {
    if (e.Item.ItemType == ListItemType.Separator) {
        if ((e.Item.ItemIndex + 1) % 3 != 0) {
            e.Item.Controls.Clear();
        }
    }
}

Solution 2

I may be confused, but why not just use a repeater and a custom item template?

Solution 3

You can achieve your desired layout using CSS without altering the original generated markup. Since span tags are displayed inline by default, switching to inline-block and specifying a width of 33% on those spans should do the trick.

Or more specifically, set the CssClass property of your DataList control to a value such as "threecolumns".

Define the following css style:

<style type="text/css">
.threecolumns span 
{
    display: inline-block;
    width: 33%;
}
</style>

VS2008 might tell you that inline-block isn't a valid setting for the display property. I wouldn't worry about that too much since almost every browser supports it.

Comments

[Ian Robinson]

Maybe I've been staring at my computer too long today (well, I know I have...) but I'm not seeing any easy solution with a repeater either, I'd welcome an example of this as well. I believe it would be reasonable for me to replace the DataList with a Repeater.

[Ian Robinson]

Thanks David. This solution will work, but what about the repeater makes this so much easier to implement? Thanks again.

[nuthan ratnam vara]

You'd actually use the exact some approach but with a Repeater. The DataList has overhead involved for doing things like rendering content in tables, which you are trying to usurp. Also it is derived from a WebControl whereas the Repeater is derived from Control.

[Ian Robinson]

Thanks David, I implemented this as my solution (using a repeater). I appreciate the help.