The Internet Operating System

A Simple GuestBook or Feedback Page Requiring No Database Implementation
Ken Alabi

As a web designer, I have been faced with the need for a simple and quick testimonial or guest book application on a basic website with no database backing. At every ocassion, I shirked at the prospect of requiring the website have a database (with or without an expensive DSN) simply for this purpose. I developed this simple text file powered database in ASP to serve the many times I will again be faced with this situation and it has made my work look good to many clients since.

The guestbook application is in the form of a single ASP script file. The application receives input from site visitors and stores the input in a simple "tag" delimited text file. The text file implementation is such that it is XML compatible. The current implementation displays the log of feedbacks entered by site visitors but could also be implemented to not display the entries. The solution could be adapted to email the guestbook entries to a specified address.

There are four parts to the ASP page
(1) Entry of information or feedback by site visitors
(2) Validation of the entered information
(3) Appending the information to a text file containing all entries
(4) Displaying all feedback that resides in the text file

Entry of Information
This is achieved by a simple html form containing a textbox for the message and an input box. A salient feature of the form shown below is the hidden form object named "submitted" which will be used in determining the action taken by the page when accessed. Notice that the action property of the form returns to the same file as represented by the ASP string (Request.ServerVariables("SCRIPT_NAME"))

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<form name="feedform" method="POST" action = "<%=Request.ServerVariables("SCRIPT_NAME")%>" OnSubmit="return Validate()">
<input type="hidden" name="submitted" value>
<table border="0" cellspacing="0" width="100%">

<tr><td width="30%"><b>Enter your comments</b></td>
<td width="70%"><textarea Name="feedbody" COLS="40" ROWS="4"></textarea></td></tr>

<tr><td width="30%"><b>Enter your Name</b></td>
<td width="70%"><input maxLength="50" Name="feedname" VALUE SIZE="45"></td>
</tr>

<tr><td width="30%"></td>
<td width="70%"><input type="submit" value=" Submit "></td></tr>

</table>
</form>

Validation
There are two validation features in the javascript validation subroutine "Validate()". First is to check that an input was entered before the form is submitted to the server. The advantage of this procedure is that validation is completed on the client computer and requests are not sent to the server (consuming central resources) until they are processable.

The second function of the validation subroutine is to set the submitted form object to true (Line 3). When the page is accessed the second time by the server, the submitted flag determines that the page is to be processed for input. This allows the entire application to be completed with one single ASP file!

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var string1 = document.feedform.feedbody.value;
if (string1 == ""){alert("You have not entered a message"); return false;}
if (string1.length >4000){alert("Your message is too long. This server accepts messages totalling only 4000 characters"); return false;}

var string1 = document.feedform.feedname.value;
if (string1 == ""){alert("You have not entered your name or signature");return false;}

return true;
}
</script>

Processing
The processing procedure performs additional activities to ensure that only one message is posted by the website visitor in one session as well as to strip the entry of any html elements.

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if (lcase(Request.Form("submitted")) = "true" )Then
   if (IsNull(Session("feedbacked"))) then
      Session("feedbacked") = False
   end if
   if (Session("feedbacked")=True) then
       errStr = "You are allowed only one message per session.</font><br>"
   else
       Session("feedbacked")=True
       smessage = Request.Form("feedbody")
       smessage = Trim(smessage)
       smessage = Replace(smessage,"<","")
       smessage = Replace(smessage,">","")
       sname = Request.Form("feedname")
       sname = Trim(sname)
       sname = Replace(sname,"<","")
       sname = Replace(sname,">","")
       sdate = Now()
       smessage = smessage & "<br><b><font color=blue>- " & sname
       smessage = smessage & " (" & sdate & ")</font></b>"

       sfile = "_feedback.txt"
       whichFN=server.mappath(sfile)
       if (whichfN <> "") and (Not IsNull(whichFN)) then
           Set fstemp = server.CreateObject("Scripting.FileSystemObject")
           if (fstemp.FileExists(whichFN) = True) then
               Set filetemp = fstemp.OpenTextFile(whichfN, 8, false, 0)
               filetemp.writeLine("<FEEDBACK>")
               filetemp.WriteLine(smessage)
               filetemp.writeLine("</FEEDBACK>")
               filetemp.Close
               set filetemp=Nothing
           end if
           set fstemp=Nothing
       end if
   end if
end if

The entire processing section is wrapped within the if block (Line 1 and Line 36) that checks if this form is being submitted for processing.

Lines 2 - 8 ensures that a website visitor can only enter one feedback in one visit from the same browser. To enter another feedback, the visitor will have to close and reopen their browser.

Lines 9 through 16 strips the entries of any html entries that could polute the feedback file.

Line 22 ensures that this application will work irrespective of which folder on the website it is copied into. Infact, a feedback could be created in as many different web folders. Line 26 opens the feedback text file in append mode (8).

Lines 27 - 29 appends the entry to the feedback text file. Each entry in the text file is delimited within the lines <FEEDBACK></FEEDBACK> making the file readable by an XML procedure. This is useful for cross-website integration.

Display of Information
The contents of the storage text file is read and displayed on the feedback page.

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sfeedback = "<font name=Verdana size=2>"
sfile = "_feedback.txt"
whichFN=server.mappath(sfile)
if (whichfN <> "") and (Not ISNull(whichFN)) then
    Set fstemp1 = server.CreateObject("Scripting.FileSystemObject")
    if (fstemp1.FileExists(whichFN) = True) then
        Set filetemp = fstemp1.OpenTextFile(whichfN, 1, false, 0)
        Do while (filetemp.AtEndofStream <> True)
            strLine = filetemp.ReadLine
            strLine = Replace(strLine,"<FEEDBACK>","")
            strLine = Replace(strLine,"</FEEDBACK>","<hr>")
            sfeedback = sfeedback & strLine
        Loop
        filetemp.Close
        Set filetemp = Nothing
    else
        Set filetemp = fstemp1.CreateTextFile(whichfN, false)
        filetemp.close
    end if
    Set fstemp1 = Nothing
end if
sfeedback = sfeedback & "</font>"

At first access, when there is no feedback and no text file, the text file is created (Line 17), otherwise, the file is opened in read mode (Line 7). This means only one file (the ASP) file needs to be copied and installed in the required directory.

The data delimited <FEEDBACK></FEEDBACK> is removed and replaced by a line break (Line 10 and 11). Data separation can be implemented using a different character or an image at this line instead of the line break tag <hr>.

The string "sfeedback" contains the total feedback that have been accumulated at the site can can be inserted anywhere on the html section of the page within the ASP script limiter <% %>. If a display of the feedback on the site is not desired this activity may be ignored. In addition, Lines 1, 22, and 7-15 may be safile deleted.

To ensure that the page is always refreshed an ASP command <%
Response.Expires =0
%> is inserted at the top of the page.

A comment must be made about the appropriateness of this application on a high volume site. It is a concern that there may be concurrency issues in the very rare situation that users try to commit their feedback at the same time. The chances of this situation ocurring increases with the rate of feedback entries. However, it goes without say that this solution would already prove undesirable given the size, volume, and time it would take for this file to load and view in that situation.