Ajax and BASIC

Ajax (Asynchronous Javascript and XML) style techniques for building interactive web applications are the rage today. They are somewhat overhyped, but there is some value there.

Run BASIC already provides an exceptionally easy web programming system, but it does so with minimal special effects. There is a tiny bit of Javascript being used but almost everything is done with XHTML on the browser, and a very smart web application server.

In release v1.0 of Run BASIC the widgets (and indeed the page itself) are all objects. They are created by very simple statements. Any sort of Ajax inspired widgets for a future release of Run BASIC must not be any more complicated to use than the simple to use widgets that are already there.

Additionally, one of the most important aspects of Ajax is partial page reloading. This is important and we are eagerly planning to add this. What this will allow you the Run BASIC program to do is to reload a small part of your web app in the browser so that each user action does cause the whole page to be refreshed from the browser. This provides for smoother feeling user experience, and it also can improve performance.

So, Ajax must not complicate Run BASIC. Our design philosophy is to respect the simplicity of BASIC as much as possible. There are too many complicated programming systems out there, and the world doesn't need another one.

Perspective is Worth 80 IQ Points

Bill Williams sums up nicely why small is beautiful when it comes to programming tools.

http://rbblog.billdubya.net/2007/10/mindset-problem.html

Parsing XML in Run BASIC

One of the important feature that a Web 2.0 language needs is an XML parser. Run BASIC now has one built in. The XMLPARSER statement parses an XML string and returns an XML accessor object with a bunch of handy built-in methods for making your way through an XML document.
Here is a simple example of what that sort of code looks like:

a$ = "<program name=""myprog"" author=""Carl Gundel""/>"
xmlparser #parser, a$
print #parser key$()
for x = 1 to #parser attribCount()
key$ = #parser attribKey$(x)
print key$; ", ";
print #parser attribValue$(x)
next x

This short program produces:

program
name, myprog
author, Carl Gundel

And here is a short program which will display the tag names and contents of an artibrarily nested XML document:

xmlparser #doc, s$
print #doc key$()
call displayElements #doc
end

sub displayElements #xmlDoc
count = #xmlDoc elementCount()
for x = 1 to count
#elem = #xmlDoc #element(x)
print "Key: "; #elem key$();
value$ = #elem value$()
if value$ <> "" then
print " Value: "; value$
end if
print
call displayElements #elem
next x
end sub

Database and web capabilities

Our Run BASIC + SQLite integration is coming along nicely, and it lays the groundwork for using other databases later on (Oracle, SQL Server, MySql, etc.). One thing that we did to make using databases handy is that we built in some display technologies. You can query the database and then just use the RENDER statement to put the result on the web page. You can also inject some CSS styling right into that result, and you can even turn the line items of any column in the displayed table into links.

We also have added an httpget$() function so you can use HTTP to retrieve web documents like web pages, RSS feeds, etc. We plan to include an XML parser, and if we can come up with an easy to use way to stream through an HTML document we will provide that also.

These capabilities (except for the table rendering) will also be included in Liberty BASIC v5.0.

To keep up with what we're doing with Run BASIC, make sure to visit this blog and also http://libertybasic.conforums.com/index.cgi?board=runbasic