More ASP using Dreamweaver UltraDev

Linking to Detail Pages

Creating links so your visitor can click on an item of data and to go to a more detailed Web page is easy using UltraDev. The link is created in the Server Behaviours window and the code looks something like this:

<A HREF="appt_level2.asp?<%= MM_keepURL & MM_joinChar(MM_keepURL) amp; "DoH=" & APPT.Fields.Item("DoH").Value %>">

After this code comes the data to be linked, which is likely to be a dynamic element, and then the closing </a> tag.

The first part of the code shown above is HTML defining the page your visitor will go to — appt_level2.asp. There's a question mark after the page address, and the URL string parameters will follow this. Putting parameters in the URL string is the easy way of transferring them from page to page.

The next elements are references to Macromedia subroutines (beginning MM) that create the new URL string. In this case we use the subroutine that collects existing parameters in the current URL string and passes them on to the next page, then a join character, and finally a new addition to the string, beginning with "DoH=". This will add a DoH code to the URL string, In our hospital example, DoH is a numeric value corresponding to a medical specialty. For example 190 is Anesthetics.

The code snippet APPT.Fields.Item("DoH").Value retrieves the appropriate value to be added to the URL string. It looks along the row of data for the DoH code and inserts it in the URL string. If we were starting off with a page that had a blank URL string, we might finish up moving to a detail page containing the string: appt_level2.asp?DoH=190.

Extracting values from strings

On the detail page appt_level2.asp, we need to extract the DoH value from the string to use it as a filtering parameter within a recordset — specifically within an SQL Select statement. Again UltraDev makes this straightforward, allowing us to specify a URL parameter for filtering during creation of the recordset.

It transfers the useful part of the URL string to a VBScript variable first. So if we are creating a recordset called rswebtotals and we use our previously mentioned DoH as a limiting element of the recordset's SQL statement, we find the following code created by UltrDev near the start of the page:

<%
Dim rswebtotals__varDOH
rswebtotals__varDOH = 100
if(Request.QueryString("DoH") <> "")
then rswebtotals__varDOH = Request.QueryString("DoH")
%>

[Lines 4 and 5 above are one line. They have been split for formatting purposes.]

This creates a variable called rswebtotals__varDOH and sets it equal to the value of DoH that it finds in the URL string. In case the string is empty, it first sets it to a user- specified value of 100. This is helpful when testing the page since it prevents missing parameter errors that might otherwise occur.

The variable rswebtotals__varDOH can also be displayed anywhere it's required on the page using the simple code <%= rswebtotals__varDOH %>.

The SQL Select Statement - Page 2