HTML::Mason::CGIHandleUser Contributed Perl DocumentHTML::Mason::CGIHandler(3)NAMEHTML::Mason::CGIHandler - Use Mason in a CGI environment
SYNOPSIS
In httpd.conf or .htaccess:
<LocationMatch "\.html$">
Action html-mason /cgi-bin/mason_handler.cgi
AddHandler html-mason .html
</LocationMatch>
<LocationMatch "^/cgi-bin/">
RemoveHandler .html
</LocationMatch>
<FilesMatch "(autohandler|dhandler)$">
Order allow,deny
Deny from all
</FilesMatch>
A script at /cgi-bin/mason_handler.pl :
#!/usr/bin/perl
use HTML::Mason::CGIHandler;
my $h = HTML::Mason::CGIHandler->new
(
data_dir => '/home/jethro/code/mason_data',
allow_globals => [qw(%session $u)],
);
$h->handle_request;
A .html component somewhere in the web server's document root:
<%args>
$mood => 'satisfied'
</%args>
% $r->err_header_out(Location => "http://blahblahblah.com/moodring/$mood.html");
...
DESCRIPTION
This module lets you execute Mason components in a CGI environment. It
lets you keep your top-level components in the web server's document
root, using regular component syntax and without worrying about the
particular details of invoking Mason on each request.
If you want to use Mason components from within a regular CGI script
(or any other Perl program, for that matter), then you don't need this
module. You can simply follow the directions in the Using Mason from a
standalone script section of the administrator's manual.
This module also provides an $r request object for use inside
components, similar to the Apache request object under
"HTML::Mason::ApacheHandler", but limited in functionality. Please
note that we aim to replicate the "mod_perl" functionality as closely
as possible - if you find differences, do not depend on them to stay
different. We may fix them in a future release. Also, if you need
some missing functionality in $r, let us know, we might be able to
provide it.
Finally, this module alters the "HTML::Mason::Request" object $m to
provide direct access to the CGI query, should such access be
necessary.
"HTML::Mason::CGIHandler" Methods
· new()
Creates a new handler. Accepts any parameter that the Interpreter
accepts.
If no "comp_root" parameter is passed to "new()", the component
root will be $ENV{DOCUMENT_ROOT}.
· handle_request()
Handles the current request, reading input from $ENV{QUERY_STRING}
or "STDIN" and sending headers and component output to "STDOUT".
This method doesn't accept any parameters. The initial component
will be the one specified in $ENV{PATH_INFO}.
· handle_comp()
Like "handle_request()", but the first (only) parameter is a
component path or component object. This is useful within a
traditional CGI environment, in which you're essentially using
Mason as a templating language but not an application server.
"handle_component()" will create a CGI query object, parse the
query parameters, and send the HTTP header and component output to
STDOUT. If you want to handle those parts yourself, see the Using
Mason from a standalone script section of the administrator's
manual.
· handle_cgi_object()
Also like "handle_request()", but this method takes only a CGI
object as its parameter. This can be quite useful if you want to
use this module with CGI::Fast.
The component path will be the value of the CGI object's
"path_info()" method.
· request_args()
Given an "HTML::Mason::FakeApache" object, this method is expected
to return a hash containing the arguments to be passed to the
component. It is a separate method in order to make it easily
overrideable in a subclass.
· interp()
Returns the Mason Interpreter associated with this handler. The
Interpreter lasts for the entire lifetime of the handler.
$r Methods
· headers_in()
This works much like the "Apache" method of the same name. In an
array context, it will return a %hash of response headers. In a
scalar context, it will return a reference to the case-insensitive
hash blessed into the "HTML::Mason::FakeTable" class. The values
initially populated in this hash are extracted from the CGI
environment variables as best as possible. The pattern is to merely
reverse the conversion from HTTP headers to CGI variables as
documented here:
http://cgi-spec.golux.com/draft-coar-cgi-v11-03-clean.html#6.1
<http://cgi-spec.golux.com/draft-coar-cgi-v11-03-clean.html#6.1>.
· header_in()
This works much like the "Apache" method of the same name. When
passed the name of a header, returns the value of the given
incoming header. When passed a name and a value, sets the value of
the header. Setting the header to "undef" will actually unset the
header (instead of setting its value to "undef"), removing it from
the table of headers returned from future calls to "headers_in()"
or "header_in()".
· headers_out()
This works much like the "Apache" method of the same name. In an
array context, it will return a %hash of response headers. In a
scalar context, it will return a reference to the case-insensitive
hash blessed into the "HTML::Mason::FakeTable" class. Changes made
to this hash will be made to the headers that will eventually be
passed to the "CGI" module's "header()" method.
· header_out()
This works much like the "Apache" method of the same name. When
passed the name of a header, returns the value of the given
outgoing header. When passed a name and a value, sets the value of
the header. Setting the header to "undef" will actually unset the
header (instead of setting its value to "undef"), removing it from
the table of headers that will be sent to the client.
The headers are eventually passed to the "CGI" module's "header()"
method.
· err_headers_out()
This works much like the "Apache" method of the same name. In an
array context, it will return a %hash of error response headers. In
a scalar context, it will return a reference to the case-
insensitive hash blessed into the "HTML::Mason::FakeTable" class.
Changes made to this hash will be made to the error headers that
will eventually be passed to the "CGI" module's "header()" method.
· err_header_out()
This works much like the "Apache" method of the same name. When
passed the name of a header, returns the value of the given
outgoing error header. When passed a name and a value, sets the
value of the error header. Setting the header to "undef" will
actually unset the header (instead of setting its value to
"undef"), removing it from the table of headers that will be sent
to the client.
The headers are eventually passed to the "CGI" module's "header()"
method.
One header currently gets special treatment - if you set a
"Location" header, you'll cause the "CGI" module's "redirect()"
method to be used instead of the "header()" method. This means
that in order to do a redirect, all you need to do is:
$r->err_header_out(Location => 'http://redirect.to/here');
You may be happier using the "$m->redirect" method, though, because
it hides most of the complexities of sending headers and getting
the status code right.
· content_type()
When passed an argument, sets the content type of the current
request to the value of the argument. Use this method instead of
setting a "Content-Type" header directly with "header_out()". Like
"header_out()", setting the content type to "undef" will remove any
content type set previously.
When called without arguments, returns the value set by a previous
call to "content_type()". The behavior when "content_type()"
hasn't already been set is undefined - currently it returns
"undef".
If no content type is set during the request, the default MIME type
"text/html" will be used.
· method()
Returns the request method used for the current request, e.g.,
"GET", "POST", etc.
· http_header()
This method returns the outgoing headers as a string, suitable for
sending to the client.
· send_http_header()
Sends the outgoing headers to the client.
· notes()
This works much like the "Apache" method of the same name. When
passed a $key argument, it returns the value of the note for that
key. When passed a $value argument, it stores that value under the
key. Keys are case-insensitive, and both the key and the value must
be strings. When called in a scalar context with no $key argument,
it returns a hash reference blessed into the
"HTML::Mason::FakeTable" class.
· pnotes()
Like "notes()", but takes any scalar as an value, and stores the
values in a case-sensitive hash.
· subprocess_env()
Works like the "Apache" method of the same name, but is simply
populated with the current values of the environment. Still, it's
useful, because values can be changed and then seen by later
components, but the environment itself remains unchanged. Like the
"Apache" method, it will reset all of its values to the current
environment again if it's called without a $key argument.
· params()
This method returns a hash containing the parameters sent by the
client. Multiple parameters of the same name are represented by
array references. If both POST and query string arguments were
submitted, these will be merged together.
Added $m methods
The $m object provided in components has all the functionality of the
regular "HTML::Mason::Request" object $m, and the following:
· cgi_object()
Returns the current "CGI" request object. This is handy for
processing cookies or perhaps even doing HTML generation (but is
that really what you want to do?). If you pass an argument to this
method, you can set the request object to the argument passed. Use
this with care, as it may affect components called after the
current one (they may check the content length of the request, for
example).
Note that the ApacheHandler class (for using Mason under mod_perl)
also provides a "cgi_object()" method that does the same thing as
this one. This makes it easier to write components that function
equally well under CGIHandler and ApacheHandler.
· cgi_request()
Returns the object that is used to emulate Apache's request object.
In other words, this is the object that $r is set to when you use
this class.
"HTML::Mason::FakeTable" Methods
This class emulates the behavior of the "Apache::Table" class, and is
used to store manage the tables of values for the following attributes
of <$r>:
headers_in
headers_out
err_headers_out
notes
subprocess_env
"HTML::Mason::FakeTable" is designed to behave exactly like
"Apache::Table", and differs in only one respect. When a given key has
multiple values in an "Apache::Table" object, one can fetch each of the
values for that key using Perl's "each" operator:
while (my ($k, $v) = each %{$r->headers_out}) {
push @cookies, $v if lc $k eq 'set-cookie';
}
If anyone knows how Apache::Table does this, let us know! In the
meantime, use "get()" or "do()" to get at all of the values for a given
key ("get()" is much more efficient, anyway).
Since the methods named for these attributes return an
"HTML::Mason::FakeTable" object hash in a scalar reference, it seemed
only fair to document its interface.
· new()
Returns a new "HTML::Mason::FakeTable" object. Any parameters
passed to "new()" will be added to the table as initial values.
· add()
Adds a new value to the table. If the value did not previously
exist under the given key, it will be created. Otherwise, it will
be added as a new value to the key.
· clear()
Clears the table of all values.
· do()
Pass a code reference to this method to have it iterate over all of
the key/value pairs in the table. Keys will multiple values will
trigger the execution of the code reference multiple times for each
value. The code reference should expect two arguments: a key and a
value. Iteration terminates when the code reference returns false,
to be sure to have it return a true value if you wan it to iterate
over every value in the table.
· get()
Gets the value stored for a given key in the table. If a key has
multiple values, all will be returned when "get()" is called in an
array context, and only the first value when it is called in a
scalar context.
· merge()
Merges a new value with an existing value by concatenating the new
value onto the existing. The result is a comma-separated list of
all of the values merged for a given key.
· set()
Takes key and value arguments and sets the value for that key.
Previous values for that key will be discarded. The value must be a
string, or "set()" will turn it into one. A value of "undef" will
have the same behavior as "unset()".
· unset()
Takes a single key argument and deletes that key from the table, so
that none of its values will be in the table any longer.
SEE ALSO
HTML::Mason, HTML::Mason::Admin, HTML::Mason::ApacheHandler
perl v5.14.2 2012-02-05 HTML::Mason::CGIHandler(3)