WebKeystone -- Lesson 3-1: Using temporary storage

WebKeystone Lesson 3-1: Using temporary storage

There are several methods available for storage and retrieval of information in your WebKeystone application. You have access to temporary storage, as well as three types of long-term storage, each of which has its own advantages and special uses. You choose the type of storage that best suits your particular needs. You may wish to refer to the comparison chart as you work your way through the data storage lessons.

Temporary storage is a simple method of storing and retrieving information in WebKeystone. The information is written to RAM (memory); it is not saved to disk. It is stored in dictionary form and is automatically deleted after 15 minutes. It is retrievable and, once retrieved, may be manipulated using the full power of WebKeystone. Here is an example which uses temporary storage for login passcodes:

The Files

This form requires eight files: the Startfile, two Profiles, four Endfiles, and a text file for mailing the Passcode.

The Startfile

<FORM ACTION="/wkstone/webkeystone.py" METHOD=POST> <INPUT TYPE=HIDDEN NAME="UserID" VALUE="biz_webkeystone"> <INPUT TYPE=HIDDEN NAME="Profile" VALUE="lessons/set3/lesson3-1Register.prof"> <CENTER> <TABLE BORDER="1" CELLPADDING="5" CELLSPACING="0" WIDTH="90%" BGCOLOR="#FFFFCC" COLS="2"> <TR> <TD> <H3>Enter registration information and click "Submit" to receive your passcode:</H3> Name:<INPUT TYPE=TEXT NAME="Name.req" SIZE=25><BR> Email:<INPUT TYPE=TEXT NAME="Email.req.vEmail" SIZE=25><BR> <INPUT TYPE=SUBMIT VALUE="Submit"><INPUT TYPE=RESET VALUE="Clear form"> </TD> </TR> </TABLE> </CENTER> </FORM>

The first Profile, named lesson3-1Register.prof

# Profile for Lesson 3-1 Registration # Check for missing required fields IF MissingReq RETURN 'lessons/set3/lesson3-1RegisterMissing.html' ELSE # Create a unique "Passcode" NEWID Passcode # Save the Passcode in temporary storage TF_WRITE Passcode # Send the Passcode to the email address MAIL TO Email FROM 'lesson3-1@webkeystone.com' SUBJECT 'Your Passcode' BODY 'lessons/set3/lesson3-1Mail.txt' RETURN 'lessons/set3/lesson3-1RegisterReturn.html'

The first Endfile, named lesson3-1RegisterReturn.html

<HTML> <HEAD> <TITLE>Lesson 3-1 Register Endfile</TITLE> </HEAD> <BODY BGCOLOR="#FFFFFF" LINK="#CC0000" VLINK=#000000 ALINK="#999999"> <H2>Your registration has been accepted</H2> Please check your email to obtain your confidential Passcode. Copy your <BR>Passcode from the email message and then come back to this form and paste <BR>it into the slot. Then click "Login" to complete the login. <FORM ACTION="/wkstone/webkeystone.py" METHOD=POST> <INPUT TYPE=HIDDEN NAME="UserID" VALUE="biz_webkeystone"> <INPUT TYPE=HIDDEN NAME="Profile" VALUE="lessons/set3/lesson3-1Login.prof"> <B>Passcode:</B><INPUT TYPE=TEXT NAME="Passcode.req"><BR> <P> <INPUT TYPE=SUBMIT VALUE="Login"> </FORM> </BODY> </HTML>

The first "Missing" Endfile, named lesson3-1RegisterMissing.html

<HTML <HEAD> <TITLE>Lesson 3-1 Register Missing Endfile</TITLE> </HEAD> <BODY BGCOLOR="#FFFFFF" LINK="#CC0000" VLINK=#000000 ALINK="#999999"> <H2>Sorry, you must enter your name and email address.</H2> <H3>Please click "Back" on your browser, enter your name and email address, and proceed.</H3> </BODY> </HTML>

The text file for mailing, named lesson3-1Mail.txt

Hello %(Name)s, Here is your confidential Passcode. Your Passcode is: %(Passcode)s Please copy and paste it into the login form in your browser. Thank You! -------------------------- This message comes to you as a result of your input in WebKeystone Lesson 3-1. Thank you for visiting the Lesson!

The second Profile, named lesson3-1Login.prof

IF MissingReq RETURN 'lessons/set3/lesson3-1LoginMissing.html' ELSE # Check to see if Passcode is valid TF_READ Passcode result IF result == 'OK' RETURN 'lessons/set3/lesson3-1LoginReturn.html' # Looks as though the Passcode is missing or invalid ELSE RETURN 'lessons/set3/lesson3-1LoginMissing.html'

The second Endfile, named lesson3-1LoginReturn.html

<HTML> <HEAD> <TITLE>Lesson 3-1 Login Page</TITLE> </HEAD> <BODY BGCOLOR="#FFFFFF" LINK="#CC0000" VLINK=#000000 ALINK="#999999"> <H2>Lesson 3-1 Login Area</H2> <H3>Congratulations! You have successfully logged in using your newly-generated Passcode.</H3> Your reward is access to our passcode-protected photo gallery. Click on any of the links below to view our images. Click your "Back" button to return from the image to this page. <P> <UL> <LI><A HREF="http://www.webkeystone.com/lessons/set3/images/lesson3-1Image1.jpg">Tana of Sitka, Alaska</A> (62K) <P> <LI><A HREF="http://www.webkeystone.com/lessons/set3/images/lesson3-1Image2.jpg">Aircraft Carrier</A> (70K) <P> <LI><A HREF="http://www.webkeystone.com/lessons/set3/images/lesson3-1Image3.jpg">Pride of Baltimore II</A> (63K) <P> <LI><A HREF="http://www.webkeystone.com/lessons/set3/images/lesson3-1Image4.gif">Sunrise in Port Townsend</A> (1.5K) </UL> <P> Please note that your Passcode will expire 15 minutes from the time you registered. If you wait 16 minutes and try to login again in using the same Passcode, you will get an error message. <P> <HR> <CENTER>Click your "Back" button twice to return to Lesson 3-1.</CENTER> <HR> </BODY> </HTML>

The second "Missing" Endfile, named lesson3-1LoginMissing.html

<HTML> <HEAD> <TITLE>Lesson 3-1 Login Missing Endfile</TITLE> </HEAD> <BODY BGCOLOR="#FFFFFF" LINK="#CC0000" VLINK=#000000 ALINK="#999999"> <H2>Sorry, your Passcode is invalid</H2> <H3>Please click your "Back" button to enter the correct Passcode. Note that Passcodes expire 15 minutes after you register. You may register again and get a new Passcode if you like. </BODY> </HTML>

Temporary storage is created and accessed via commands in your Profile:

TF_READ <filename> ___<variable>: Opens and reads a temporary file. The variables read from the temporary file are the same as the variables written to the temporary file (see TF_WRITE below). The file name <filename> should be created using the NEWID command. Since the temporary file area is shared among users, it is important that the file name is both unique and secure; the NEWID command ensures this. <variable> is used to indicate success or failure; it will be set equal to "OK" if the file read was successful. A temporary file that exists for fifteen minutes without being read is automatically destroyed.
TF_WRITE <filename> ___<variable> ___<variable>: Writes a temporary file. The <variable> and all other variables in the indented list are written to the temporary file named <filename>. When this file is read, the variables are restored.
TF_DELETE <filename>: Deletes the temporary file named <filename>.
NEWID <variable>: Creates a variable named <variable> which contains a unique series of twenty characters. This is used with TF_WRITE to create temporary passwords or to create files with unique names.

Here is a sample portion of a Profile which creates a temporary file, using the NEWID and TF_WRITE commands:

# Create a unique "Passcode" NEWID Passcode # Save the Passcode in a temporary file TF_WRITE Passcode # Send the Passcode to the email address # ("Passcode" gets substituted into the .mail file) MAIL TO Email FROM 'lesson3-1@webkeystone.com' SUBJECT 'Your Passcode' BODY 'lesson3-1Passcode.mail'

For another illustration of temporary storage, visit Example 2, which uses temporary storage in its second Profile to store Voter IDs (login passwords) which expire after 15 minutes.

Updated 10-August-99