Component Based Web Development

As a followup to the modules post I made a few days ago which is applicable to both Liberty BASIC and Run BASIC, Scott and I have created something very web specific for Run BASIC.

In addition to inserting graphics into a web page, Run BASIC's RENDER statement can now be used to insert a module into a web page. We have this in a rough state now. It does work, but we need to iron out a couple of things.

What is this useful for? You can now create different parts of your web application as separate programs. You load them in and render them into the page. You can also control them using their own functions.

For example you might have a blog application with different parts of the page rendered by their own modules:

• BannerLogin
• Navigation bar
• Entries
• Archive outline
• etc.

Each component has it's own little virtual page which you can print to, embed graphics into, cls, add links and other stuff to, etc. The contents of the component are managed automatically. Only a RENDER statement is needed.

By using the DIV and CSS statements, the modules can be formatted on the web page in an attractive and useful way.

Modules and Run/Liberty BASIC

People have been asking for a way to create code libraries in Liberty BASIC for some time. I have thinking about how to do this using an in-memory model. Over the weekend Scott and I worked on adding some modularity to the Run/Liberty BASIC language. Here's how it works so far. We are open to suggestions.

The RUN statement has a new form. If I want to use mymodule.bas as a module in a program I am writing I would code it like this:

run "mymodule.bas", #myModule

This causes mymodule.bas to be compiled into memory. It will execute code up to the first wait statement. This is how values will be initialized. The program then becomes an object assigned to the #myModule handle.

Then you can call any function on that program from within the calling program, like so:

#myModule myFunction(myParameter)

or even use the invokation in a more complex expression:

print "digits: "; len(#myModule myFunction(myParameter))

You may recognize this syntax as being the same as for controlling widgets. It relies on the same underlying mechanisms to do its work.

When we're done with this, modular programs loaded this way will be cached in memory and will only recompile when the source file changes.