SMX (computer language)

SMX (from Server Macro Expansion) is a macro processing language designed to embed macros in web pages. Originally shipped with the popular Internet Factory's Commerce Builder software, it has been ported as an Apache module.

Overview

SMX was designed to embed macros in HTML/XML pages. It originally shipped with the Internet Factory's Commerce Builder software, a relatively popular web server in the early days of the Internet, due to the ease with which a developer could produce an e-commerce website.

Rather than re-implement websites in more popular languages, like Perl or PHP, a small group of SMX fans decided to re-implement the language itself as an Apache module.

A good example of a macro is %counter(). This embeds a simple incremental counter on an HTML page. To include the results of a SQL query on a page, you can simply type %sql(<dsn>,<query>,%col(1)<br />) in the middle of an XHTML page.

Owing to the high-level nature of the language, SMX can greatly reduce the programming effort required to build dynamic or database-driven web sites.

Syntax

Unlike many programming languages, SMX syntax is simple and consistent. All functions begin with a % sign, followed by the name of the function, followed either a single % sign or a parenthetical list of arguments.

Arguments can be quoted using double-quotes. Backslashes can be used to escape commas and double-quotes. A single quote at the beginning of an argument turns off interpretation of code in that argument (similar to LISP).

Everything that is not code, is, by default, output. To change this behavior, use the %nil or %null macros.

Sample code

Hello World

Here is a Hello World code example:

%expand%
Hello World!

Using variables to create output

%expand%
%set(name,World)
Hello %name%!

Forms processing

%expand%
%if(%form(expr)
    ,<p>Result is: %expr(%form(expr))</p>
)
<form action="%client-url%" method=post>
Simple math expression: <input name=expr>
</form>

Page counter

%expand%
%counter(hits) hits

Database guestbook

%expand%
%if(%not(%exists(/tmp/gbook.sq3))
        ,%sql(sqlite:/tmp/gbook.sq3,CREATE TABLE guests (name text, comment text))
)
%if(%and(%form(name),%form(comment))
    ,%sql(sqlite:/tmp/gbook.sq3,"INSERT INTO guests (name, comment) VALUES (%sqlq(%form(name)),%sqlq(%form(comment)))")
)
%sql(sqlite:/tmp/gbook.sq3,SELECT * FROM guests
        ,<p>%html-quote(%col(name)) said %html-quote(%col(comment))<hr>
         <p>
         <form action="%client-url%" method=post>
         <br>Name: <input name=name>
         <br>Comment: <input name=comment>
         <br><input type=submit>
         </form>
)

External links

• http://www.smxlang.org/ (open source implementation of SMX in C++)
• http://www.gjt.org/javadoc/org/opensmx/opensmx/ (open source implementation of SMX in Java)
• http://www.strom.com/pubwork/iwcb.html (review of the original commerce builder)