1HTML::Mason(3) User Contributed Perl Documentation HTML::Mason(3)
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6 Mason - High-performance, dynamic web site authoring system
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9 PerlModule HTML::Mason::ApacheHandler
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11 <Location />
12 SetHandler perl-script
13 PerlHandler HTML::Mason::ApacheHandler
14 </Location>
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17 Mason is a tool for building, serving and managing large web sites. Its
18 features make it an ideal backend for high load sites serving dynamic
19 content, such as online newspapers or database driven e-commerce sites.
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21 Actually, Mason can be used to generate any sort of text, whether for a
22 web site or not. But it was originally built for web sites and since
23 that's why most people are interested in it, that is the focus of this
24 documentation.
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26 Mason's various pieces revolve around the notion of "components''. A
27 component is a mix of HTML, Perl, and special Mason commands, one
28 component per file. So-called "top-level" components represent entire
29 web-pages, while smaller components typically return HTML snippets for
30 embedding in top-level components. This object-like architecture
31 greatly simplifies site maintenance: change a shared component, and you
32 instantly changed all dependant pages that refer to it across a site
33 (or across many virtual sites).
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35 Mason's component syntax lets designers separate a web page into
36 programmatic and design elements. This means the esoteric Perl bits can
37 be hidden near the bottom of a component, preloading simple variables
38 for use above in the HTML. In our own experience, this frees content
39 managers (i.e., non-programmers) to work on the layout without getting
40 mired in programming details. Techies, however, still enjoy the full
41 power of Perl.
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43 Mason works by intercepting innocent-looking requests (say,
44 http://www.yoursite.com/index.html) and mapping them to requests for
45 Mason components. Mason then compiles the component, runs it, and
46 feeds the output back to the client.
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48 Consider this simple Mason component:
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50 % my $noun = 'World';
51 Hello <% $noun %>!
52 How are ya?
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54 The output of this component is:
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56 Hello World!
57 How are ya?
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59 In this component you see a mix of standard HTML and Mason elements.
60 The bare '%' prefixing the first line tells Mason that this is a line
61 of Perl code. One line below, the embedded <% ... %> tag gets replaced
62 with the return value of its contents, evaluated as a Perl expression.
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64 Beyond this trivial example, components can also embed serious chunks
65 of Perl code (say, to pull records from a database). They can also call
66 other components, cache results for later reuse, and perform all the
67 tricks you expect from a regular Perl program.
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70 Mason has been tested under Linux, FreeBSD, Solaris, HPUX, and Win32.
71 As an all-Perl solution, it should work on any machine that has working
72 versions of Perl 5.00503+, mod_perl, and the required CPAN modules.
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74 Mason has a standard MakeMaker-driven installation. See the README file
75 for details.
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78 This section assumes that you are able to install and configure a
79 mod_perl server. Relevant documentation is available at
80 http://www.apache.org (Apache) and http://perl.apache.org (mod_perl).
81 The mod_perl mailing list, archive, and guide are also great resources.
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83 The simplest configuration of Mason requires a few lines in your
84 httpd.conf:
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86 PerlModule HTML::Mason::ApacheHandler
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88 <Location />
89 SetHandler perl-script
90 PerlHandler HTML::Mason::ApacheHandler
91 </Location>
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93 The PerlModule directive simply ensures that the Mason code is loaded
94 in the parent process before forking, which can save some memory when
95 running mod_perl.
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97 The <Location> section routes all requests to the Mason handler, which
98 is a simple way to try out Mason. A more refined setup is discussed in
99 the Controlling Access via Filename Extension section of the
100 administrator's manual.
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102 Once you have added the configuration directives, restart the server.
103 First, go to a standard URL on your site to make sure you haven't
104 broken anything. If all goes well you should see the same page as
105 before. If not, recheck your Apache config files and also tail your
106 server's error log.
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108 If you are getting "404 Not Found" errors even when the files clearly
109 exist, Mason may be having trouble with your document root. One
110 situation that will unfortunately confuse Mason is if your document
111 root goes through a symbolic link. Try expressing your document root in
112 terms of the true filesystem path.
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114 Next, try adding the tag <% 2+2 %> at the top of some HTML file. If you
115 reload this page and see a "4", Mason is working!
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118 Once Mason is on its feet, the next step is to write a component or
119 two. The Mason Developer's Manual is a complete tutorial for writing,
120 using, and debugging components. A reference companion to the
121 Developer's Manual is the Request API documentation,
122 HTML::Mason::Request.
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124 Whoever is responsible for setting up and tuning Mason should read the
125 Administrator's Manual, though developers will also benefit from
126 reading it as well. This document covers more advanced configuration
127 scenarios and performance optimization. The reference companion to the
128 Administrator's manual is the Parameters Reference, which describes all
129 the parameters you can use to configure Mason.
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131 Most of this documentation assumes that you're running Mason on top of
132 mod_perl, since that is the most common configuration. If you would
133 like to run Mason via a CGI script, refer to the
134 HTML::Mason::CGIHandler documentation. If you are using Mason from a
135 standalone program, refer to the Using Mason from a Standalone Script
136 section of the administrator's manual.
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138 There is also a book about Mason, Embedding Perl in HTML with Mason, by
139 Dave Rolsky and Ken Williams, published by O'Reilly and Associates.
140 The book's website is at http://www.masonbook.com/. This book goes
141 into detail on a number of topics, and includes a chapter of recipes as
142 well as a sample Mason-based website.
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145 Jonathan Swartz <swartz@pobox.com>, Dave Rolsky <autarch@urth.org>, Ken
146 Williams <ken@mathforum.org>, John Williams <williams@tni.com>
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149 Copyright (c) 1998-2005 Jonathan Swartz. All rights reserved. This
150 program is free software; you can redistribute it and/or modify it
151 under the same terms as Perl itself.
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153 The full text of the license can be found in the LICENSE file included
154 with this module.
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157 HTML::Mason::Devel, HTML::Mason::Admin
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161perl v5.12.0 2010-05-03 HTML::Mason(3)