Question

I’m working on building an HTTPHandler that will serve up plain text for use with jQuery Autocomplete. I have it working now except for when I insert the first bit of text it does not take me to the right portion of the alphabet.

Example: If I enter Ne

my drop down returns

Nlabama
Arkansas

Notice the “N” from Ne and the “labama” from “Alabama”

As I type the third character New, then the jQuery returns the “N” section of the results.

My current code looks like this

Public Sub ProcessRequest(ByVal context As System.Web.HttpContext) Implements System.Web.IHttpHandler.ProcessRequest
    ''# the page ContentType is plain text
    HttpContext.Current.Response.ContentType = "text/plain"

    ''# store the querystring as a variable'
    Dim qs As Nullable(Of Integer) = Integer.TryParse(HttpContext.Current.Request.QueryString("ID"), Nothing)

    ''# use the RegionsDataContext'
    Using RegionDC As New DAL.RegionsDataContext

        ''# create a (q)uery variable'
        Dim q As Object

        ''# if the querystring PID is not blank'
        ''# then we want to return results based on  the PID'
        If Not qs Is Nothing Then
            ''# that fit within the Parent ID'
            q = (From r In RegionDC.bt_Regions _
                    Where r.PID = qs _
                   Select r.Region).ToArray

            ''# now we loop through the array'
            ''# and write out the ressults'
            For Each item In q
                HttpContext.Current.Response.Write(item & vbCrLf)
            Next

        End If


    End Using
End Sub

So where I’m at now is the fact that I stumbled on the “Part” portion of the Autocomplete method whereby I should only return information that is contained within the Part.

My question is, how would I implement this concept into my HTTPHandler without doing a fresh SQLQuery on every character change? IE: I do the SQL Query on the QueryString(“ID”), and then on every subsequent load of the same ID, we just filter down the “Part”.

http://www.example.com/ReturnRegions.axd?ID=%5BsomeID%5D&Part=%5Bstring%5D

Answer 1

I changed my jQuery library to use the jQuery-UI and then built my iHttpHandler using a Singleton object in order to avoid hitting the database on every page load. The answer here seems to be working well for me.