Article
Embedding Perl Into Web Pages
'Apache::ASP'
Apache::ASP is an implementation of Active Server Pages (see Chapter 9 for more on ASP) for the Apache web server using Perl as the scripting engine – for more details, see the web site at http://www.apache-asp.org/. After installation of the module, directives such as the following samples are inserted into Apache's httpd.conf file:
PerlModule Apache::ASP
Alias /asp/ "/home/www/asp/"
<Location /asp>
SetHandler perl-script
PerlHandler Apache::ASP
PerSetVar Global /tmp
PerlSetVar CookiePath /
</Location>
This assumes a mod_perl-enabled server. Any file placed in the /asp directory will be parsed by the Apache::ASP Apache handler.
As with Mason and Embperl, we give the simple example of printing out the values of the various environment variables:
<!--#include file=header.inc-->
<H3>Environment Variables</H3>
<CENTER>
<TABLE BORDER=1>
<TR><TH COLSPAN=2 ALIGN="left">Environment Variables</th></tr>
<% @colors = ("#FFFFFF", "#CCCCCC");
$x = 0;
sub _color{
return $x++ % 2 ? $colors[0] : colors[1];
}%>
<% for(sort keys %{$Request->ServerVariables()}) {
next unless /HTTP|SERVER|REQUEST/; %>
<TR BGCOLOR=<%=_color()%>>
<TD><TT><%=$_%></TT> </TD>
<TD><TT><%=$Request->ServerVariables($_)%></TT></TD>
</TR>
<% } %>
</TABLE>< /CENTER>
<!--#include file=footer.inc-->
The invoked file, header.inc, is:
<%
$title = 'My Apache::ASP demo'; %> <HTML>
<HEAD>
<TITLE><%=$title%></TITLE><
/HEAD>
<BODY BGCOLOR="#ffffff" link="#ff5599" vlink="#993399">
<BR />
The footer.inc file is given by:
<P>
Comments to
<A HREF="mailto:me@my.address.com">me</a>
are welcome.
</BODY>
</HTML>
In Apache::ASP, Perl code is enclosed within <%...%> blocks. Variables to be printed out use the <%=$variable_name %> syntax. The environment variables themselves are contained within $Request->ServerVariables – note that we restrict the variables to match the regular expression /HTTP|SERVER|REQUEST/. If the file above is called environ3.html, a screenshot of the result of calling http://localhost/asp/environ3.html appears below:
In the above example, $Request->ServerVariables was used to access the server environment variables. As the syntax indicates, $Request is an object and ServerVariables is a method available for that object. Apache::ASP supports a number of such (global) objects; the current ones available are:
$Session– user session state$Response– output to browser$Request– input from browser$Application– application state$Server– general support methods
There are many methods available for each of these objects – consult the documentation for a full description.