NAME
Apache2::PodBrowser - show your POD in a browser
INSTALLATION
perl Makefile.PL
make
make test
make install
DESCRIPTION
Yet another mod_perl2 handler to view POD in a HTML browser. See
"HISTORY" for more information.
Direct Mode
"Apache2::PodBrowser" can run in *direct* and *perldoc* modes. In direct
mode apache takes care of the URI to filename translation. So,
"$r->filename" points to a regular file when the request hits
"Apache2::PodBrowser"'s handler. Use this mode if your POD files are
installed in one directory tree which is accessible through the WEB
server. You'll perhaps need an additional directory index handler.
Perldoc Mode
In *perldoc* mode you specify a "Location" where the handler resides. If
you append a module name to the location URL as in
http://localhost/location/Apache2::PodBrowser
you'll get its documentation.
Further, in perldoc mode you can ask for documentation for a given perl
function similar to "perldoc -f open" at the command line. Simply call
the location and give the wanted function as CGI keyword:
http://localhost/location/?open
The same works also for special variables. Try
http://localhost/location/?$_
and you'll see the documentation for $_.
Usually you want to use perldoc mode. It allows you to access PODs at
their natural locations. On the downside, it is of course a bit slower.
Indexes
Also in perldoc mode, there are 2 indexes available, one of all
installed modules and scripts that come with POD and one of built-in
functions and variables.
The the handler location itself shows the module index:
http://localhost/location/
If a single question mark "?" is given as CGI keyword the function and
variable index is shown:
http://localhost/location/??
Don't worry you don't have to remember all these URLs. The pages are
properly linked together.
CONFIGURATION
Direct Mode
Direct mode's basic configuration look like this:
<Directory /...>
Options +Indexes
<Files ~ "\.p(od|m|l)">
SetHandler modperl
PerlResponseHandler Apache2::PodBrowser
PerlSetVar STYLESHEET /path/to/style.css
PerlSetVar PARSER Apache2::PodBrowser::DirectMode
</Files>
</Directory>
All *.pod, *.pm and *.pl files will magically be converted to HTML.
Perldoc Mode
For perldoc mode add the following lines to your httpd.conf:
<Location /perldoc>
SetHandler modperl
PerlHandler Apache2::PodBrowser
PerlFixupHandler Apache2::PodBrowser::Fixup
PerlSetVar STYLESHEET fancy
</Location>
You can then get documentation for module "Apache2::PodBrowser" at
<http://localhost/perldoc/Apache2::PodBrowser>.
Finally, a particular Perl built-in function's or variable's
documentation is at
<http://localhost/perldoc/?function_or_variable_name>. For example
<http://localhost/perldoc/?open> or <http://localhost/perldoc/?$_>.
At <http://localhost/perldoc/> you'll see a module index and at
<http://localhost/perldoc/??> an index over all built-in functions and
variables.
Configuration Variables
The following variables affect the work of "Apache2::PodBrowser". They
are all set by "PerlSetVar" or "PerlAddVar". See t/conf/extra.conf.in
for example configurations.
STYLESHEET
Specifies the stylesheet to use with the output HTML file.
PerlSetVar STYLESHEET /path/to/style.css
There are 2 stylesheets *auto* and *fancy* that come with this module.
They are installed alongside in @INC. To use them either teach your
Apache to look for them or use the provided fixup handler:
PerlFixupHandler Apache2::PodBrowser::Fixup
PerlSetVar STYLESHEET fancy # or auto
If you want to use your own stylesheet simply specify its URL.
To use one of the built in styles in direct mode you have to teach
apache where it is located. One way is to use an "Alias" and make the
file accessible. Another is to use the provided fixup handler. For
example
<Directory /some/directory>
Options +Indexes
<Files ~ "\.p(od|m)">
SetHandler modperl
PerlResponseHandler Apache2::PodBrowser
PerlSetVar STYLESHEET /auto.css
PerlSetVar PARSER Apache2::PodBrowser::DirectMode
</Files>
<Files *.css>
PerlFixupHandler Apache2::PodBrowser::Fixup
</Files>
</Directory>
In direct mode the stylesheet must be given as a complete URL not just
"auto" or "fancy".
INDEX
When INDEX is true, a table of contents is added at the top of the HTML
document.
PerlSetVar INDEX 1
By default, this is off.
The "fancy" stylesheet places the index into a sort of drop-down menu
that is placed fixed at the right top corner of the page. So, it is
always at hand if you want to jump to another part of the document. This
works in most browsers with the necessary CSS support. Notably, the
Internet Explorer is not among them.
GZIP
When GZIP is true, the whole HTTP body is compressed. The browser must
accept gzip, and Compress::Zlib must be available. Otherwise, GZIP is
ignored.
An appropriate "Vary" header is issued to make proxy servers happy.
Also the environment variables "no-gzip" and "gzip-only-text/html" that
can be set for example by the "BrowserMatch" directive are regarded. See
the mod_deflate documentation
<http://httpd.apache.org/docs/2.2/mod/mod_deflate.html#recommended> for
more information
PerlSetVar GZIP 1
By default, this is off.
PODDIR
This variable is useful only in perldoc mode.
It declares additional directories to look for PODs. This can be given
multiple times. Directories given this way are searched before @INC.
PerlAddVar PODDIR /path/to/project1
PerlAddVar PODDIR /path/to/project2
NOINC
In perldoc mode POD files are normally looked up in @INC plus in the
directories given by "PODDIR". If "NOINC" is set then the @INC search is
skipped. That means only the directories specifed in httpd.conf are
scanned:
PerlAddVar NOINC 1
For documentation requests for perl functions via
<http://localhost/perldoc/?functionname> @INC is used nevertheless to
locate "perlfunc.pod" if it is not found in one of the given
directories.
In direct mode this variable is ignored.
CACHE
When in perldoc mode "Apache2::PodBrowser" uses Pod::Find::pod_find to
generate a list of available POD files. This may take quite a while
depending upon the number of directories and files to scan for POD.
To avoid to repeat this for each POD index request one can set up a
cache.
PerlSetVar CACHE /path/to/cache.mmdb
The cache file itself is created on the first access to the index. The
POD index page then contains a link to update the cache. So, if a POD
file is added or removed from the system this link is to be clicked to
keep the POD index page up to date.
The cache file itself is a MMapDB object. If this module is not
available you'll probably get a "404 - NOT FOUND" response the next time
the POD index page is requested if "CACHE" is set.
The directory containing the cache file must be writable by the "httpd".
CONTENTTYPE
You'll probably need that only for plain text output with the
Pod::Simple::Text parser. Here one can set the content type of the
output.
PerlSetVar CONTENTTYPE "text/plain; charset=UTF-8"
PARSER and LINKBASE
"PARSER" sets the POD-to-HTML converter class that is used. It should
support at least the interface that Pod::Simple::Text provides.
The Pod::Simple::Text parser gives you plain text.
If Pod::Simple::HTML is used as parser one gets almost usable output
except for the missing "DOCTYPE" HTML header and the broken linkage to
other modules.
The default "PARSER" is "Apache2::PodBrowser::Formatter" and is suitable
for perldoc mode. It derives from Pod::Simple::HTML but overrides the
constructor "new" to provide a "DOCTYPE" and "resolve_pod_page_link" to
fix the linkage.
If "LINKBASE" is not set or empty "resolve_pod_page_link" creates
relative links to other modules of the type:
./Other::Module
If "LINKBASE" is set it is prepended before "Other::Module" instead of
"./". For example you could set
PerlSetVar LINKBASE http://search.cpan.org/perldoc?
to generate links to CPAN.
For perldoc mode an empty "LINKBASE" is best choice.
In direct mode an other parser "Apache2::PodBrowser::DirectMode" should
be used. It derives from "Apache2::PodBrowser::Formatter" but overrides
"resolve_pod_page_link".
This time the link generator searches for the link destination POD by
the module name with one of the following extensions appended: ".pod",
".pm" and ".pl". If none is found it resorts to its base class. And now
"LINKBASE" makes sense.
If you know of a "Apache2::PodBrowser" running in perldoc mode you can
point "LINKBASE" to that address. This way modules that does not exist
in the local tree would be looked up there or on CPAN if "LINKBASE"
points there.
If all that is unsuitable for you you can implement your own "PARSER"
class. Have a look at the source code of this module. It is quite
straight forward regarding the 2 parser classes.
The Fixup Handler
If you use your own stylesheet or teach apache to find one of the
provided styles in the file system you don't need the fixup handler.
It simply does the file lookup for you.
If you don't like it just find the style sheet in your file system:
find $(perl -e 'print "@INC"') -type f -name fancy.css
copy it into your "DocumentRoot" and set "STYLESHEET" to find it.
WHISHLIST
* speed up POD index generation
HISTORY
As you may know there is already Apache2::Pod::HTML. This module has
borrowed some ideas from it but is implemented anew. In fact, I had
started by editing Apache2::Pod::HTML 0.27 but at a certain moment I had
patched it into something that only vaguely remembered the original
code. When the HTML functionality was ready I discovered that
Apache2::Pod::Text had also to be taken care of. That was too much to
bear.
Differences from Apache2::Pod::HTML as of version 0.01
* POD index
an index of all PODs found in the given scan directories is returned
if the handler is called in "perldoc" mode without a module
argument.
* NOINC variable
* PODDIR variable
* PARSER variable
* CONTENTTYPE variable
new configuration variables
* proper HTTP protocol handling
Apache2::Pod::HTML does not issue a "Vary" HTTP header in GZIP mode.
It does not support turning off GZIP for certain browsers by
"BrowserMatch". And it does not sent "Content-Length",
"Last-Modified" or "ETag" headers.
"Apache2::PodBrowser" issues correct headers when GZIP is on. It
also sends "ETag", "Last-Modified" and "Content-Length" headers. And
it checks if a conditional GET request meets its conditions and
answers with HTTP code 304 (NOT MODIFIED) if so.
* using CGI keywords instead of "PATH_INFO"
how to pass function names to the handler in "perldoc -f" mode
* proper HTTP error codes
Apache2::Pod::HTML returns HTTP code 200 even if there is no POD
found by a given name
* CSS: fancy stylesheet
"Apache2::PodBrowser" comes with 2 stylesheets, see above
* CSS: sent by default handler
"Apache2::PodBrowser" uses a fixup handler to reconfigure apache to
ship included stylesheets by it's default response handler.
* much better test suite
"Apache2::PodBrowser" uses the Apache::Test framework to test its
work. Apache2::Pod::HTML tests almost only the presence of POD.
Embedding HTML in POD
POD provides the
=begin html
...
=end html
or
=for html ...
syntax. This module supports it. If you look at this document via this
module you'll probably see a picture of me on the right side.
Example:
=begin html
<img align="right"
alt="Picture of ..."
src="http://host.name/image.jpg"
border="0">
=end html
You might notice that the image URL is absolute. Wouldn't it be good to
bundle the images with the module, install them somewhere beside it in
@INC and reference them relatively?
It is possible to do that in perldoc mode. Just strip off the ".pm" or
".pod" suffix from the installed perl module file name and make a
directory with that name. For example assuming that this module is
installed as:
/perl/lib/Apache2/PodBrowser.pm
create the directory
/perl/lib/Apache2/PodBrowser
and place the images there.
To include them in POD write:
=begin html
<img align="right"
alt="Picture of ..."
src="./Apache2::PodBrowser/torsten-foertsch.jpg"
border="0">
=end html
If the POD file name doesn't contain a dot (".") the last path component
is stripped off to get the directory name.
Note that you need to write the package name again. You also need to
either escape the semicolons as in
"src="Apache2%3A%3APodBrowser/torsten-foertsch.jpg"" or put a "./" in
front of the link.
A note about the content type of linked documents. "Apache::PodBrowser"
does not enter a new request cycle to ship these documents. So, the
normal Apache Content-Type guessing does not take place.
"Apache::PodBrowser" knows a few file name extensions ("png", "jpg",
"jpeg", "gif", "js", "pdf" and "html"). For those it sends the correct
Content-Type headers. All other documents are shipped as
"application/octet-stream".
If a document needs a different Content-Type header it can be passed as
CGI parameter:
src="Apache2%3A%3APodBrowser/torsten-foertsch.jpg?ct=text/plain"
The link above will ship the image as "text/plain".
SEE ALSO
Apache2::Pod::HTML
Pod::Simple
Pod::Simple::HTML
Pod::Simple::Text
AUTHOR
Torsten Förtsch "<torsten.foertsch@gmx.net>"
LICENSE
This package is licensed under the same terms as Perl itself.