Aestiva H2O Web Site

Installation:
  Free Downloads
  The H2O Family
  Install Notes

Programming:
  Prerequisites
  H2O Whitepaper
  Online Manual
  Code Examples
  H2O Free Support

What's H2O?
H2O is programming made for the web.

What's it like?
H2O is English-like. If you know some Perl, VB, ASP, or PhP you'll be immediately productive in H2O. It runs on Linux, Mac, Unix, and Windows.

How do I try it?
Download H2O for free. Get it from hosting providers. Or buy on-line.

Where does H2O come from?
The language was invented by Aestiva. H2O stands for:
   HTML with
   HTML/OS
   Overlays.

Multi-Staff Login

Writing a login page from scratch is done by adding a macro at the bottom of your login page. This code is a good example of a simple login page that reads its login-password pairs from a text file.

The top of the file defines the file name that stores your login-password pairs. This is followed by the HTML Form of your login page. Note how the form is linked to the on-click Overlay (macro) that checks the login file for a valid login-password pair.

The Onclick Overlay
The COPY function is used to load the data. Note the specification of the table delimiter (TS=","). This is needed since the file is comma-delimited (also known as CSV). The COPY function lopads the file into the array checkpassword. Then the function GETCOLEQ is used to find only those lines where column 1 equals the login name specified. Then an IF statement is used to see if the line found (stored in the variable checkpassword) has the password in its second column, as it should, if the login-password pair specified was correct.

login.html


<<
   loginfile="users.txt"
   welcomepage="menu.html"
>>

<html>
<title>Mulit-Staff Login</title>
<<
  IF errmessage <> "ERROR" DO
    DISPLAY '<font color=red><b>' + errmessage + 
            '</b></font><br><br>' 
    /DISPLAY
    errmessage = "ERROR"
  /IF

>>
<form method=post action=checkpassword><br>
Name: 
<input type=text size=30 name=multicheckname><br>
Password: 
<input type=password size=30 name=multicheckpassword>
<input type=submit value="Enter">
</form>
</html>

<<OVERLAY checkpassword
    # load login,password pairs from file /#
    IF multicheckname="" THEN
      errmessage = "Bad Login." 
      GOTO PAGE
    /IF
    COPY FILE=loginfile TS="," TO checkpassword /COPY
    checkpassword = GETCOLEQ(checkpassword,1,multicheckname)
    IF checkpassword = "" THEN
      errmessage = "Bad Login."
      GOTO PAGE
    /IF
    IF multicheckpassword != checkpassword[2,1] THEN
      errmessage = "Bad Login."
      GOTO PAGE
    /IF
    accesslevel = checkpassword[3,1]
    GOTO welcomepage
  >>


NOTE: The users.txt file is assumed to be comma-delimited. The login IDs
are stored in clolumn 1 and the passwords are stored in column 2. For example:

  jsmith,mypassword
  achen,mypassword2
  bbabson,mypassword3
  admin,mypassword4
  jjackson,mypassword5
  wpeter,password6