Jacksonville Developers User Group

Hi,

Can someone tell me how to (or point me in the right direction)

implement an alphabetical filter (hyperlink-look) in my web app?

I currently have a combo-box alphabetical filter that someone was nice enough to post, but I

prefer the hyperlink flavor and I don't know how to modify it to fit.

Thanks in advance!

The Universe has no center and I am it.

The superior man is modest in his speech, but exceeds in his actions.

Yes, Exactly!

I could probably try for some demo code like Thomas did later tonight, but just brainstorming here . . .

I'd probably start with a datasource that exposed a couple of methods for retrival (a single letter version, and a letter range [encyclopedia style "A - Am", "An - Ba", etc], and of course an ALL option).  If I were doing ASP.NET 1.1 code, I'd look at the PagedDataSource for handling some of this.

If I were doing it in ASP.NET 1.1 I'd look at the ItemCreated event of the DataGrid for making my footer (similiar to the code that Thomas provided) and I'd look at the ItemCommand event for handling the clicks of each item, calling the data, and rebinding to the control.

For ASP.NET 2.0, alot of these features got wrapped write into the GridView, so there is even less work to do after you have your data source set up.

If you still need a direct demo, I'll whip one up tonite after work, provided someone else here doesnt beat me to it.

The Universe has no center and I am it.

The superior man is modest in his speech, but exceeds in his actions.

Thanks for the code.

I copied and pasted - I'm getting two error messages:

Type 'List' is not defined.

&

Type 'KeyValuePair' is not defined.

In 'Design' view, it looks like it's starting do what I want, just not quite there yet.  Going to try and figure out exactly what your code is doing and see if I can find out what I need to do.  Or you could tell me....... :0)

For what it's worth, I'm using Visual Web Developer Express 2005.......

Imports System.Collections.Generic

I can just hear the groans and imagine the looks of disbelief.  Sorry!

Don't forget - "Newbie" as in "Totally green".  Please be patient.  I do appreciate any help at all.

I am getting an error when I try to run the page - Name 'Eval' is not delcared.

Any ideas?

Sorry for the lateness of the reply, but life, liberty, and the pursuit of paper often gets in the way.

My solution is inherently similiar to Thomas' but uses a GridView as I described originally. 

Start with a GridView Control. You will need something that acts as a datasource.  I used a country list, with name and country code.  I created a small utility class to wrap up access to it, with a GetAllCountries and GetCountriesByAbbreviation methods.

Next, I wire up the RowCreated event inorder to create the alpha list in the footer

    Private Sub GridView1_RowCreated(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridView1.RowCreated
        If e.Row.RowType = DataControlRowType.Footer Then
            For AsciiLetter As Integer = 0 To 25
                Dim AlphaLinkButton As LinkButton = New LinkButton()
                AlphaLinkButton.Text = Char.ConvertFromUtf32(AsciiLetter + 65)
                AlphaLinkButton.CommandArgument = Char.ConvertFromUtf32(AsciiLetter + 65)
                AlphaLinkButton.CommandName = "AlphabeticalPager"
                e.Row.Cells(0).Controls.Add(AlphaLinkButton)

                'spacer cheat -- should use CSS instead
                Dim spacer As New System.Web.UI.HtmlControls.HtmlGenericControl("span")
                spacer.InnerHtml = " "
                e.Row.Cells(0).Controls.Add(spacer)
            Next
        End If
    End Sub

This puts the list at the bottom and sets up the links to fire back on the server.  So now we need an event to catch those and reset the list.

    Private Sub GridView1_RowCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewCommandEventArgs) Handles GridView1.RowCommand
        If e.CommandName = "AlphabeticalPager" Then
            GridView1.DataSource = CountriesDataSource.GetCountriesByAbbreviation(Convert.ToChar(e.CommandArgument))
            GridView1.DataBind()
        End If
    End Sub

So that's that.  The real key is the code Thomas already gave you.  The next step is to get it into a GridView or similiar control and handle the server events.

Let me know is this is helpful or you need anything else.

The Universe has no center and I am it.

The superior man is modest in his speech, but exceeds in his actions.

you may be missing a quote some where.

Text='<%# Eval("Value") %>'

Without looking at how you are using it in your solution... you could just explicitly break it down like this.

Text='<%# DataBinder.Eval(Container.DataItem, "Value") %>'

Okay!

Finally, the repeater control looks like it should....

Now, I'm at the point where I actually need to filter my DataSet based on the "clicked"

alphabetLink.  From what I've been reading on the internet, I need to iterate through the repeater collection and get ItemData.  Is there no simple way to just drill down to the clicked button.

Like (using the above code from TBates) hyperLinks.alphabetLink.Text?

Here's what I have and, of course, it doesn't work:

From the solution that TBates has given you thus far, you could add this into your client side code for your link button . . .

Then, you could just use the argument in the repeater's ItemCommand event, something like:

    Private Sub hyperLinks_ItemCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.RepeaterCommandEventArgs) Handles hyperLinks.ItemCommand
        If e.CommandName = "alphaSort" Then
            Label1.Text = "You selected: " & e.CommandArgument
        End If
    End Sub

The Universe has no center and I am it.

The superior man is modest in his speech, but exceeds in his actions.

Well, in my humble opinion, you will not find many books out there with examples for problems such as this.  This just comes from familiarity with ASP.NET and the .NET Framework itself.

The Oreilly book ASP.NET by Jesse Liberty is a good starting point for ASP.NET.

The GridViewGuy has quite a collection of how to do some non-"HELLOWORLD" things with gridviews and such.

Then, of course, there are your fellow JaxDUG members (cheesy and shameless plug, I know).