This is Info file pm.info, produced by Makeinfo version 1.68 from the input file bigpm.texi.  File: pm.info, Node: Apache/Language/Constants, Next: Apache/Language/DBI, Prev: Apache/Language, Up: Module List Apache::Language constants for use by LanguageHandlers ****************************************************** NAME ==== Apache::Language::Constants - Apache::Language constants for use by LanguageHandlers SYNOPSIS ======== use Apache::Language::Constants; DESCRIPTION =========== These are constants LanguageHandlers can use to return status information to Apache::Language. The constants and their respective signification are as follow: L_OK Return with this value whenever something correctly ends L_ERROR Return with this value whenever something bad has happened. By bad, I mean something that will prevent you to complete the required task and that some form of error should be generated in the logs. L_DECLINED return with this value in the initialize routine to indicate you are not interested in being called to answer queries for that package. How you decide this is up to you. Remember to return undef when a search retrieves nothing and all will be ok. SEE ALSO ======== perl(1), *Note Apache: Apache,(3), *Note Apache/Language: Apache/Language,(3). SUPPORT ======= Please send any questions or comments to the Apache modperl mailing list or to me at AUTHOR ====== Philippe M. Chiasson COPYRIGHT ========= Copyright (c) 1999 Philippe M. Chiasson. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.  File: pm.info, Node: Apache/Language/DBI, Next: Apache/Language/PlainFile, Prev: Apache/Language/Constants, Up: Module List DBI interface for Apache::Language ********************************** NAME ==== Apache::Language::DBI - DBI interface for Apache::Language SYNOPSIS ======== PerlSetVar Language::DBI::Datasource DBI:Pg:dbname=database;host=database.host PerlSetVar Language::DBI::Username webserver PerlSetVar Language::DBI::Password unguessable PerlSetVar Language::DBI::TableName language [default] Language::DBI::TableKey key [column for the key] Language::DBI::TableLang lang [column for the lang] Language::DBI::TableValue value [column for the value] LanguageHandler Apache::Language::DBI DESCRIPTION =========== This LanguageHandler implements a per-location DBI dictionnary. It looks-up a given table for a matching language/key pair and returns the best possible match. The configurable directives are pretty self-explanatory. TODO ==== Some sort of caching could be done. SEE ALSO ======== perl(1), *Note Apache: Apache,(3), *Note Apache/Language: Apache/Language,(3) *Note Apache/Language/Constants: Apache/Language/Constants,(3), and all `Apache::Language::*' in this node. SUPPORT ======= Please send any questions or comments to the Apache modperl mailing list or to me at NOTES ===== This code was made possible by : * Doug MacEachern Creator of mod_perl. That should mean enough. * Andreas Koenig The one I got the idea from in the first place. * The mod_perl mailing-list at for all your mod_perl related problems. AUTHOR ====== Philippe M. Chiasson COPYRIGHT ========= Copyright (c) 1999 Philippe M. Chiasson. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.  File: pm.info, Node: Apache/Language/PlainFile, Next: Apache/Language/SW, Prev: Apache/Language/DBI, Up: Module List Default LanguageHandler under Apache::Language ********************************************** NAME ==== Apache::Language::PlainFile - Default LanguageHandler under Apache::Language SYNOPSIS ======== Since it's the default handler, it never needs to be activated. DESCRIPTION =========== This is the default LanguageHandler under Apache::Language. It searches language definitions for a specific script/module in a file with a corresponding name. For a script, it's the scriptname with a .dic added. For a module, simply replace the .pm with a .dic That file must reside in the same directory as the script/module it describes, and be readable by the web-server process. The format of that file is as follows: language-tag:Key Content for 'language' version of 'Key' language-tag:Key [...] The only really important thing is to make sure that entries are separated with completely blank lines. TODO ==== Nothing for now. SEE ALSO ======== perl(1), *Note Apache: Apache,(3), *Note Apache/Language: Apache/Language,(3) *Note Apache/Language/Constants: Apache/Language/Constants,(3), and all `Apache::Language::*' in this node. SUPPORT ======= Please send any questions or comments to the Apache modperl mailing list or to me at NOTES ===== This code was made possible by : * Doug MacEachern Creator of mod_perl. That should mean enough. * Andreas Koenig The one I got the idea from in the first place. * The mod_perl mailing-list at for all your mod_perl related problems. AUTHOR ====== Philippe M. Chiasson COPYRIGHT ========= Copyright (c) 1999 Philippe M. Chiasson. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.  File: pm.info, Node: Apache/Language/SW, Next: Apache/Layer, Prev: Apache/Language/PlainFile, Up: Module List LanguageHandler for SmartWorker Applications ******************************************** NAME ==== Apache::Language::SW - LanguageHandler for SmartWorker Applications SYNOPSIS ======== sub new { my $classname = shift; my $self = $classname->SUPER::new(@_); $self->{Language} = new Apache::Language($self); [...] } [...] -text => $self->{Language}{"keyName1"}, [...] #outside a FormPanel $Panel->addElement(x,y,$self->{Language}->getLanguagePicker()); #inside a FormPanel $Panel->addElement(x,y,$self->{Language}->getLanguagePicker("formPanel1)); [...] DESCRIPTION =========== This is the new way to handle Language in SW::Applications. The interface is a tied hash, so you can use the object returned by Apache::Language like any other hash reference. There are also a few function calls you can make on it, like the getLanguagePicker() sub that returns a Language picker panel ready to insert in your application. The only restriction with this module is that it uses the 'Lang' key to find wanted languages. So it sets it in the Session/Data stuff. So don't do this: $self->{Lang} = "I love perl"; or $self->setSessionValue("Lang","I love perl"); ok ? But you can look at it if you want to know what language are requested by the user, but I advise against it. METHODS ======= getLanguagePicker - Returns a formpanel with a correct language picker for the current user. Arguments : if already in form context, call it with the name of the formpanel you are adding it to. AUTHOR ====== Philippe M. Chiasson HBE gozer@hbe.ca Sept 9/99 REVISION HISTORY ================ $Log$ SEE ALSO ======== perl(1). Apache::Language(3). Apache::Language::*(3).  File: pm.info, Node: Apache/Layer, Next: Apache/Leak, Prev: Apache/Language/SW, Up: Module List Layer content tree over one or more others. ******************************************* NAME ==== Apache::Layer - Layer content tree over one or more others. SYNOPSIS ======== #httpd.conf PerlTransHandler Apache::Layer # anywhere you can configure a location PerlSetVar apache_layer_location /project/images PerlSetVar apache_layer_path /dir1/root;/dir2/root DESCRIPTION =========== This module is designed to allow multiple content trees to be layered on top of each other within the Apache server. I developed this module because we produce lots of web sites where a high proportion of the site content is common. But where specific pages / images are tailored to the specific project. This module allows us to layer a sparse directory tree on top of the main complete tree without requiring redirects. The essence is that it will cause Apache to deliver content from a series of directories in turn. In some ways Apache::Layer is similar to Apache::Stage however it does not require redirects. COMMON PROBLEMS =============== Apache::Layer is relatively simple. The most common problem is not setting the apache_layer_location parameter correctly. As a rule this parameter should ALWAYS match the parameter within the location i.e. . AUTHOR ====== Simon Matthews REVISION ======== $Revision: 1.7 $ COPYRIGHT ========= Copyright (C) 1998 Simon Matthews. All Rights Reserved. This module is free software; you can distribute it and/or modify it under the same terms as Perl itself. SEE ALSO ======== Apache::Stage  File: pm.info, Node: Apache/Leak, Next: Apache/Log, Prev: Apache/Layer, Up: Module List Module for tracking memory leaks in mod_perl code ************************************************* NAME ==== Apache::Leak - Module for tracking memory leaks in mod_perl code SYNOPSIS ======== use Apache::Leak; leak_test { my $obj = Foo->new; $obj->thingy; }; #now look in error_log for results DESCRIPTION =========== "Under Construction." SEE ALSO ======== Devel::Leak AUTHOR ====== Doug MacEachern Leak.xs derived from Nick Ing-Simmons' Devel::Leak  File: pm.info, Node: Apache/Log, Next: Apache/LogFile, Prev: Apache/Leak, Up: Module List Interface to Apache logging *************************** NAME ==== Apache::Log - Interface to Apache logging SYNOPSIS ======== use Apache::Log (); my $rlog = $r->log; $rlog->debug("You only see this if `LogLevel' is set to `debug'"); my $slog = $r->server->log; DESCRIPTION =========== The Apache::Log module provides an interface to Apache's *ap_log_error* and *ap_log_rerror* routines. emerg alert crit error warn notice info debug AUTHOR ====== Doug MacEachern SEE ALSO ======== mod_perl(3), Apache(3).  File: pm.info, Node: Apache/LogFile, Next: Apache/MP3, Prev: Apache/Log, Up: Module List Interface to Apache's logging routines ************************************** NAME ==== Apache::LogFile - Interface to Apache's logging routines SYNOPSIS ======== #in httpd.conf PerlModule Apache::LogFile PerlLogFile |perl/mylogger.pl My::Logger #in a Perl script print My::Logger "a message to the Log" DESCRIPTION =========== The *PerlLogFile* directive can be used to hook a Perl filehandle to a piped logger or to a file open for appending. If the first character of the filename is a |, the file handle is opened as a pipe to the given program. The file or program can be relative to the *ServerRoot*. The method interface was written before mod_perl directive handlers were introduced, but it still works so the documentation remains below: The new method should be called by a server startup script or module. The last argument to new is optional, it is simply a name that can be used to retrive the filehandle via the handle method. #in a startup file use Apache::LogFile (); Apache::LogFile->new("|perl/mylogger.pl", "MyLogger"); #in a request-time file use Apache::LogFile (); my $fh = Apache::LogFile->handle("MyLogger"); print $fh "a message to the log"; If this argument is not present, the filename will be used the handle key, which can also be retrived via the handle method. The new method will return a reference to the filehandle if you wish to store it elsewhere, e.g.: $MyLog::Pipe = Apache::LogFile->new("|perl/mylogger.pl"); $MyLog::Append = Apache::LogFile->new("logs/my_log"); AUTHOR ====== Doug MacEachern SEE ALSO ======== Apache(3), mod_perl(3)  File: pm.info, Node: Apache/MP3, Next: Apache/MP3/Playlist, Prev: Apache/LogFile, Up: Module List Generate streamable directories of MP3 files ******************************************** NAME ==== Apache::MP3 - Generate streamable directories of MP3 files SYNOPSIS ======== # httpd.conf or srm.conf AddType audio/mpeg mp3 MP3 AddType audio/playlist m3u M3U # httpd.conf or access.conf SetHandler perl-script PerlHandler Apache::MP3 # Or use the Apache::MP3::Sorted subclass to get sortable directory listings SetHandler perl-script PerlHandler Apache::MP3::Sorted # Or use the Apache::MP3::Playlist subclass to get persistent playlists SetHandler perl-script PerlHandler Apache::MP3::Playlist A *demo version* can be browsed at http://www.modperl.com/Songs/. DESCRIPTION =========== This module makes it possible to browse a directory hierarchy containing MP3 files, sort them on various fields, download them, stream them to an MP3 decoder like WinAmp, and construct playlists. The display is configurable and subclassable. NOTE: This version of Apache::MP3 is substantially different from the pre-2.0 version described in The Perl Journal. Specifically, the format to use for HREF links has changed. See *Linking* for details. Installation ------------ This section describes the installation process. 1. Prequisites This module requires mod_perl and MP3::Info, both of which are available on CPAN. 2. Configure MIME types Apache must be configured to recognize the mp3 and MP3 extensions as MIME type audio/mpeg. Add the following to httpd.conf or srm.conf: AddType audio/mpeg mp3 MP3 AddType audio/playlist m3u M3U 3. Install icons and stylesheet This module uses a set of icons and a cascading stylesheet to generate its song listings. By default, the module expects to find them at the url /apache_mp3. Create a directory named apache_mp3 in your document root, and copy into it the contents of the `apache_mp3' directory from the Apache-MP3 distribution. You may change the location of this directory by setting the BaseDir configuration variable. See the Customizing section for more details. 4. Set Apache::MP3 to be the handler for the MP3 directory In httpd.conf or access.conf, create a or section, and make Apache::MP3 the handler for this directory. This example assumes you are using the URL /Songs as the directory where you will be storing song files: SetHandler perl-script PerlHandler Apache::MP3 If you would prefer an MP3 file listing that allows the user to sort it in various ways, set the handler to use the Apache::MP3::Sorted subclass instead. A further elaboration is Apache::MP3::Playlist, which uses cookies to manage a persistent playlist for the user. 5. Load MP3::Info in the Perl Startup file (optional) For the purposes of faster startup and memory efficiency, you may load the MP3::Info module at server startup time. If you have a mod_perl "startup" file, enter these lines: use MP3::Info; use Apache::MP3; 6. Set up MP3 directory Create a directory in the web server document tree that will contain the MP3 files to be served. The module recognizes and handles subdirectories appropriately. I suggest organizing directories hierarchically by artist and/or album name. If you place a file named "cover.jpg" in any of the directories, that image will be displayed at the top of the directory listing. You can use this to display cover art. If you place a list of .mp3 file names in a file with the .m3u extension, it will be treated as a playlist and displayed to the user with a distinctive icon. Selecting the playlist icon will download the playlist and stream its contents. The playlist must contain relative file names, but may refer to subdirectories, as in this example: # file: folk_favorites.m3u Never_a_Moment_s_Thought_v2.mp3 Peter Paul & Mary - Leaving On A Jet Plane.mp3 Simon and Garfunkel/Simon And Garfunkel - April Come She Will.mp3 7. Set up an information cache directory (optional) In order to generate its MP3 listing, Apache::MP3 must open each sound file, extract its header information, and close it. This is time consuming, particularly when recursively generating playlists across multiple directories. To speed up this process, Apache::MP3 has the ability cache MP3 file information in a separate directory area. To configure this, choose a directory that the Web server has write access for, such as /usr/tmp. Then add a configuration variable like the following to the directive: PerlSetVar CacheDir /usr/tmp/mp3_cache If the designated directory does not exist, Apache::MP3 will attempt to create it, limited of course by the Web server's privileges. You may need to create the mp3_cache directory yourself if /usr/tmp is not world writable. Open up the MP3 URL in your favorite browser. You should be able to see directory listings, and download and stream your songs. If things don't seem to be working, checking the server error log for messages. CUSTOMIZING =========== Apache::MP3 can be customized in three ways: (1) by changing per-directory variables; (2) changing settings in the Apache::MP3 cascading stylesheet; and (3) subclassing Apache::MP3 or Apache::MP3::Sorted. Per-directory configuration variables ------------------------------------- Per-directory variables are set by PerlSetVar directives in the Apache::MP3 or section. For example, to change the icon displayed next to subdirectories of MP3s, you would use PerlSetVar to change the DirectoryIcon variable: PerlSetVar DirectoryIcon big_cd.gif This following table summarizes the configuration variables. A more detailed explanation of each follows in the subsequent sections. Table 1: Configuration Variables Name Value Default ---- ----- ------- GENERAL OPTIONS AllowDownload yes|no yes AllowStream yes|no yes AllowPlayLocally yes|no yes CheckStreamClient yes|no no ReadMP3Info yes|no yes StreamTimeout integer 0 DIRECTORY OPTOINS BaseDir URL /apache_mp3 CacheDir path -none- HelpURL URL apache_mp3_help.gif:614x498 StreamBase URL -none- DISPLAY OPTIONS ArrowIcon URL right_arrow.gif CoverImage filename cover.jpg DescriptionFormat string -see below- DirectoryIcon URL cd_icon_small.gif PlaylistIcon URL playlist.gif Fields list title,artist,duration,bitrate HomeLabel string "Home" LongList integer 10 PathStyle Staircase|Arrows Staircase SongIcon URL sound.gif SubdirColumns integer 3 Stylesheet URL apache_mp3.css TitleIcon URL cd_icon.gif General Configuration Variables ------------------------------- AllowDownload *yes|no* You may wish for users to be able to stream songs but not download them to their local disk. If you set AllowDownload to "no", Apache::MP3 will not generate a download link for MP3 files. It will also activate some code that makes it inconvenient (but not impossible) for users to download the MP3s. The module recognizes the arguments "yes", "no", "true" and "false". The default is "yes". Note that this setting only affects MP3 files. Other files, including cover art and playlists, can still be downloaded. AllowStream *yes|no* If you set AllowStream to "no", users will not be able to stream songs or generate playlists. I am not sure why one would want this feature, but it is included for completeness. The default is "yes." AllowPlayLocally *yes|no* If you set AllowPlayLocally to "yes", then the playlists generated by the module will point to the physical files when handling requests from a user that happens to be working on the same machine. This is more efficient, and allows the user to pause playback, fast forward, and so on. Otherwise, the module will treat local users and remote users the same. The default is "no". CheckStreamClient *yes|no* Setting CheckStreamClient to "yes" enables code that checks whether the client claims to be able to accept streaming MPEG data. This check isn't foolproof, but supports at least the most popular MP3 decoders (WinAmp, RealPlayer, xmms, mpg123). It also makes it harder for users to download songs by pretending to be a streaming player. The default is "no". ReadMP3Info *yes|no* This controls whether to extract field information from the MP3 files. The default is "yes". If "no" is specified, all fields in the directory listing will be blank except for filename and description, which will both be set to the physical filename of the MP3 file. StreamTimeout integer For demo mode, you can specify a stream timeout in seconds. Apache::MP3 will cease streaming the file after the time specified. Because this feature uses the average bitrate of the song, it may be off by a second or two when streaming variable bitrate MP3s. Configuration Variables Affecting Paths and Directories ------------------------------------------------------- BaseDir URL The BaseDir variable sets the URL in which Apache::MP3 will look for its icons and stylesheet. You may use any absolute local or remote URL. Relative URLs are not accepted. The default is "/apache_mp3." CacheDir path This variable sets the directory path for Apache::MP3's cache of MP3 file information. This must be an absolute path in the physical file system and be writable by Apache. HelpURL *URL:widthxheight* The URL of the page to display when the user presses the "Quick Help Summary" link at the bottom of the page. In the current implementation, the module pops up a plain window containing a marked-up GIF of a typical page. You can control the size of this page by adding ":WxH" to the end of the URL, where W and H are the width and height, respectively. Default: apache_mp3_help.gif:614x498 Note: I prepared this image on an airplane, so it isn't as clean as I would like. Volunteers to make a better help page are welcomed! StreamBase URL A URL to use as the base for streaming. The default is to use the same host for both directory listings and streaming. This may be of use for transparent reverse proxies or for situations in which you want one server to generate the index, and the other to service the stream requests. Example: If the song requested is http://www.foobar.com/Songs/Madonna_live.m3u?stream=1 and StreamBase is set to *http://streamer.myhost.net*, then the URL placed in the playlist will be http://streamer.myhost.net/Songs/Madonna_live.m3u?stream=1 The path part of the URL is simply appended to StreamBase. If you want to do more sophisticated URL processing, use *mod_rewrite* or equivalent. Configuration Variables Affecting the Visual Display ---------------------------------------------------- ArrowIcon URL Set the icon used for the arrows displayed between the components of the directory path at the top of the directory listing. CoverImage filename Before displaying a subdirectory, Apache::MP3 will look inside the directory for an image file. This feature allows you to display digitized album covers or other customized icons. The default is "cover.jpg", but the image file name can be changed with CoverImage. If the file does not exist, the image specified by TitleIcon will be displayed instead. DescriptionFormat string The "Description" field, which is used both in the Description column of the directory index and in the metadata sent to the player during streaming, has a default format of title-artist-album. The description is constructed in such a way that the hyphen is omitted if the corresponding field of the song's MP3 tag is empty. You can customize this behavior by providing a DescriptionFormat string. These strings combine constant characters with %x format codes in much the way that sprintf() does. For example, the directive shown below will create descriptions similar to *[Madonna] Like a Virgin (1980)*. PerlSetVar DescriptionFormat "[%a] %t (%y)" The full list of format codes follows: Table 2: DescriptionFormat Field Codes Code Description ---- ----------- %a Artist name %c Comment %d Duration, in format 00m00s %f Name of physical file (minus path) %g Genre %l Album name %m Minutes portion of duration, usually used with %s %n Track number %q Sample rate, in kHz %r Bitrate, in kbps %s Seconds portion of duration, usually used with %m %S Duration, expressed as total seconds %t Title %y Year DirectoryIcon URL Set the icon displayed next to subdirectories in directory listings, "cd_icon_small.gif" by default. PlaylistIcon URL Set the icon displayed next to playlists in the playlist listings, "playlist.gif" by default. Fields *title,artist,duration,bitrate* Specify what MP3 information fields to display in the song listing. This should be a list delimited by commas, "|" symbols, or any other non-word character. The following are valid fields: Table 3: Field Names For use with the Fields Configuration Variable Field Description ----- ----------- album The album artist The artist bitrate The bitrate, expressed in kbps comment The comment field duration Duration of the song in hour, minute, second format description Description as specified by DescriptionFormat filename The physical name of the .mp3 file genre The genre min The minutes portion of the duration seconds Total duration of the song in seconds sec The seconds portion of the duration samplerate The sampling rate, in KHz title The title of the song track The track number year The album year Note that MP3 rip and encoding software differ in what fields they capture and the exact format of such fields as the title and album. Field names are case insensitive. Previous versions of this module used "kbps" instead of "bitrate". This has been changed. HomeLabel string This is the label for the link used to return to the site's home page. You may use plain text or any fragment of HTML, such as an tag. LongList integer The number of lines in the list of MP3 files after which it is considered "long". In long lists, the control buttons are placed at the top as well as at the bottom of the table. Defaults to 10. PathStyle *Staircase|Arrows* Controls the style with which the parent directories are displayed. The options are "Staircase" (the default), which creates a staircase-style display (each child directory is on a new line and offset by 0.3 em). The other is "Arrows", in which the entire directory list is on a single line and separated by graphic arrows. Try them both and choose the one you prefer. SongIcon URL Set the icon displayed at the beginning of each line of the MP3 file list, "sound.gif" by default. SubdirColumns integer The number of columns in which to display subdirectories (the small "CD icons"). Default 3. PlaylistColumns integer The number of columns in which to display playlists. Default 3. Stylesheet URL Set the URL of the cascading stylesheet to use, "apache_mp3.css" by default. If the URL begins with a slash it is treated as an absolute URL. Otherwise it is interpreted as relative to the BaseDir directory. TitleIcon URL Set the icon displayed next to the current directory's name in the absence of a coverimage, "cd_icon.gif" by default. In this, and the other icon-related directives, relative URLs are treated as relative to BaseDir. Stylesheet-Based Configuration ------------------------------ You can change the appearance of the page by changing the cascading stylesheet that accompanies this module, *apache_mp3.css*. The following table describes the tags that can be customized: Table 4: Stylesheet Class Names Class Name Description ---------- ---------- BODY General defaults H1 Current directory path H2 "CD Directories" and "Song List" headings TR.title Style for the top line of the song listing TR.normal Style for odd-numbered song listing lines TR.highlight Style for even-numbered song listing lines .directory Style for the title of the current directory .subdirectory Style for the title of subdirectories P Ordinary paragraphs A Links INPUT Fill-out form fields Subclassing this Module ----------------------- For more extensive customization, you can subclass this module. The Apache::MP3::Sorted module illustrates how to do this. Briefly, your module should inherit from Apache::MP3 (or Apache::MP3::Sorted) either by setting the `@ISA' package global or, in Perl 5.6 and higher, with the `use base' directive. Your module can then override existing methods and define new ones. This module uses the mod_perl method invocation syntax for handler invocation. Because of this, if you override the handler() method, be sure to give it a prototype of ($$). If you override new(), be sure to place the Apache::Request object in an instance variable named 'r'. See the MP3.pm module for details. One implication of using the method invocation syntax is that the Apache::MP3 object is created at server configuration time. This means that you cannot tweak the code and simply restart the server, but must formally stop and relaunch the server every time you change the code or install a new version. This disadvantage is balanced by a savings in memory consumption and performance. See The Apache::MP3 API below for more information on overriding Apache::MP3 methods. Linking to this module ====================== You may wish to create links to MP3 files and directories manually. The rules for creating HREFs are different from those used in earlier versions of Apache::MP3, a decision forced by the fact that the playlist format used by popular MP3 decoders has changed. The following rules apply: Download an MP3 file Create an HREF using the unchanged name of the MP3 file. For example, to download the song at /songs/Madonna/like_a_virgin.mp3, use: Like a Virgin Stream an MP3 file Replace the MP3 file's extension with .m3u and add the query string "play=1". Apache::MP3 will generate a playlist for the streaming MP3 decoder to load. Example: Like a streaming Virgin Stream a directory Append "/playlist.m3u?Play+All=1" to the end of the directory name: Madonna Lives! The capitalization of "Play All" is significant. Apache::Mp3 will generate a playlist containing all MP3 files within the directory. Stream a directory heirarchy recursively Append "/playlist.m3u?Play+All+Recursive=1" to the end of the directory name: Rock me The capitalization of "Play All Recursive" is significant. Apache::MP3 will generate a playlist containing all MP3 files within the directory and all its subdirectories. Shuffle and stream a directory Append "/playlist.m3u?Shuffle+All=1" to the end of the directory name: Rock me Apache::MP3 will generate a playlist containing all MP3 files within the directory and all its subdirectories, and then randomize its order. Shuffle an entire directory heirarchy recursively Append "/playlist.m3u?Shuffle+All+Recursive=1" to the end of the directory name: Rock me Apache::MP3 will generate a playlist containing all MP3 files within the directory and all its subdirectories, and then randomize its order. Play a set of MP3s within a directory Append "/playlist.m3u?Play+Selected=1;file=file1;file=file2..." to the directory name: Two favorites Again, the capitalization of "Play Selected" counts. Display a sorted directory Append "?sort=field" to the end of the directory name, where field is any of the MP3 field names: Madonna lives! The Apache::MP3 API =================== The Apache::MP3 object is a blessed hash containing a single key, r, which points at the current request object. This can be retrieved conveniently using the r() method. Apache::MP3 builds up its directory listing pages in pieces, using a hierarchical scheme. The following diagram summarizes which methods are responsible for generating the various parts. It might help to study it alongside a representative HTML page: list_directory() ------------------------- page top -------------------------------- directory_top() -> -> [Shuffle All] [Stream All] list_subdirs() subdir_list_top() ------------------------------------------------------------ subdir_list() <cdicon> <title> <cdicon> <title> <cdicon> <title> <cdicon> <title> <cdicon> <title> subdir_list_bottom() # does nothing ------------------------------------------------------------ list_playlists() playlist_list_top() ------------------------------------------------------------ <CD Playlists (6)> playlist_list() <cdicon> <title> <cdicon> <title> <cdicon> <title> <cdicon> <title> <cdicon> <title> <cdicon> <title> playlist_list_bottom() # does nothing ------------------------------------------------------------ list_mp3s() mp3_list_top() ------------------------------------------------------------ <Song List (4)> mp3_list() mp3_list_top() mp3_table_header() <Select> Title Kbps format_song() # called for each row <icon>[] [fetch][stream] Like a virgin 128 <icon>[] [fetch][stream] American Pie 128 <icon>[] [fetch][stream] Santa Evita 96 <icon>[] [fetch][stream] Boy Toy 168 mp3_list_bottom() [Play Selected] [Shuffle All] [Play All] directory_bottom() ------------------------- page bottom ----------------------------- Method Calls ------------ This section lists each of the Apache::MP3 method calls briefly. $response_code = handler($request) This is a the standard mod_perl handler() subroutine. It creates a new Apache::MP3 object, and then invokes its run() method. $mp3 = Apache::MP3->new(@args) This is a constructor. It stores the passed args in a hash and returns a new Apache::MP3 object. If a single argument is passed it assumes that it is an Apache::Request object and stores it under the key "r". You should not have to modify this method. $request = $mp3->r() Return the stored request object. $boolean = $mp3->is_local() Returns true if the requesting client is on the same machine as the server. $response_code = $mp3->run() This is the method that interprets the CGI parameters and dispatches to the routines that draw the directory listing, generate playlists, and stream songs. $response_code = $mp3->process_directory($dir) This is the top-level method for generating the directory listing. It performs various consistency checks on the passed directory URL and returns an Apache response code. The list_directory() method actually does most of the formatting work. $response_code = $mp3->download_file($file) This method is called to download a file (not stream it). It is passed the URL of the requested file and returns an Apache response code. It checks whether downloads are allowed and if so allows Apache to take its default action. $response_code = $mp3->stream($file) This method is called to stream an MP3 file. It is passed the URL of the requested file and returns an Apche response code. It checks whether streaming is allowed and then passes the request on to send_stream(). $mp3->send_playlist($urls,$shuffle) This method generates a playlist that is sent to the browser. It is called from various places. `$urls' is an array reference containing the MP3 URLs to incorporate into the playlist, and `$shuffle' is a flag indicating that the order of the playlist should be randomized prior to sending it. No return value is returned. $mp3_info = $mp3->find_mp3s($recurse) This method searches for all MP3 files in the currently requested directory. `$recurse', if true, causes the method to recurse through all subdirectories. The return value is a hashref in which the keys are the URLs of the found MP3s, and the values are hashrefs containing the MP3 tag fields recovered from the files ("title", etc.). @urls = $mp3->sort_mp3s($mp3_info) This method sorts the hashref of MP3 files returned from find_mp3s(), returning an array. The implementation of this method in Apache::MP3 sorts by physical file name only. Apache::MP3::Sorted has a more sophisticated implementation. @mp3s = $mp3->load_playlist($playlist) This method loads a playlist file (.m3u) from disk and returns a list of MP3 files contained in the playlist. $mp3->playlist_list_bottom($playlists) This method generates the footer at the bottom of the list of playlists given by `$playlists'. Currently it does nothing. $mp3->playlist_list($playlists) This method displays the playlists given by `$playlists' in a nicely formatted table. $html = $mp3->format_playlist($playlist) This method formats the indicated playlist by creating a fragment of HTML containing the playlist icon, the stream links and the playlist name. It returns a HTML fragment used by playlist_list(). $response_code = $mp3->list_directory($dir) This is the top level formatter for directory listings. It is passed the URL of a directory and returns an Apache response code. $mp3->directory_top($dir) This method lists the top part of the directory, including the title, the directory navigation list, and the big CD Icon in the upper left. $mp3->generate_navpath_staircase($dir) This method generates the list of parent directories, displaying them as links so that the user can navigate. It takes the URL of the current directory and returns no result. $mp3->generate_navpath_arrows($dir) This method does the same, except that the parent directories are displayed on a single line, separated by arrows. $mp3->directory_bottom($dir) This method generates the bottom part of the directory listing, including the module attribution and help information. $mp3->subdir_list_top($directories) This method generates the heading at the top of the list of subdirectories. `$directories' is an arrayref containing the subdirectories to display. $mp3->subdir_list_bottom($directories) This method generates the footer at the bottom of the list of subdirectories given by `$directories'. Currently it does nothing. $mp3->subdir_list($directories) This method invokes sort_subdirs() to sort the subdirectories given by `$directories' and displays them in a nicely-formatted table. @directories = $mp3->sort_subdirs($directories) This method sorts the subdirectories given in `$directories' and returns a sorted list (not an arrayref). $html = $mp3->format_subdir($directory) This method formats the indicated subdirectory by creating a fragment of HTML containing the little CD icon, the shuffle and stream links, and the subdirectory's name. It returns an HTML fragment used by subdir_list(). $mp3->get_help This subroutine generates the "Quick Help Summary" link at the bottom of the page. $mp3->list_subdirs($subdirectories) This is the top-level subroutine for listing subdirectories (the part of the page in which the little CD icons appears). `$subdirectories' is an array reference containing the subdirectories to display $mp3->list_playlists($playlists) This is the top-level subroutine for listing playlists. `$playlists' is an array reference containing the playlists to display. $mp3->list_mp3s($mp3s) This is the top-level subroutine for listing MP3 files. `$mp3s' is a hashref in which the key is the path of the MP3 file and the value is a hashref containing MP3 tag info about it. This generates the buttons at the top of the table and then calls mp3_table_header() and mp3_list_bottom(). $mp3->mp3_table_header This creates the first row (table headers) of the list of MP3 files. $mp3->mp3_list_bottom($mp3s) This method generates the buttons at the bottom of the MP3 file listing. `$mp3s' is a hashref containing information about each file. $mp3->mp3_list($mp3s) This routine sorts the MP3 files contained in `$mp3s' and invokes format_song() to format it for the table. @buttons = $mp3->control_buttons Return the list of buttons printed at the bottom of the MP3 file listing. $arrayref = $mp3->format_song($song,$info,$count) This method is called with three arguments. `$song' is the path to the MP3 file, $info is a hashref containing tag information from the song, and $count is an integer containing the song's position in the list (which currently is unusued). The method invokes format_song_controls() and format_song_fields() to generate a list of elements to be incorporated into cells of the table, and returns an array reference. @array = $mp3->format_song_controls($song,$info,$count) This method is called with the same arguments as format_song(). It returns a list (not an arrayref) containing the "control" elements of one row of the MP3 list. The control elements are all the doo-dads on the left-hand side of the display, including the music icon, the checkbox, and the [fetch] and [stream] links. @array = $mp3->format_song_fields($song,$info,$count) This method is called with the same arguments as format_song(). It returns a list (not an arrayref) containing the rest of a row of the MP3 file display. This will include the title, artist, and so forth, depending on the values of the Fields configuration. variable. ($directories,$mp3s) = $mp3->read_directory($dir) This method reads the directory in $dir, generating an arrayref containing the subdirectories and a hashref containing the MP3 files and their information, which are returned as a two-element list. $hashref = $mp3->fetch_info($file) This method fetches the MP3 information for $file and returns a hashref containing the MP3 tag information as well as some synthesized fields. The synthesized fields are track, which contains the same information as tracknum; description, which contains the title, album and artist merged together; and *duration*, which contains the duration of the song expressed as hours, minutes and seconds. Other fields are taken directly from the MP3 tag, but are downcased (for convenience to other routines). Apache::MP3->path_escape($scalarref) This is a limited form of CGI::escape which does not escape the slash symbol ("/"). This allows URIs that correspond to directories to be escaped safely. The escape is done inplace on the passed scalar reference. @fields = $mp3->fields Return the fields to display for each MP3 file. Reads the Fields configuration variable, or uses a default list. $hashref = $mp3->read_cache($file) Reads the cache for MP3 information about the indicated file. Returns a hashref of the same format used by fetch_info(). $boolean = $mp3->write_cache($file,$info) Writes MP3 information to cache. $file and $info are the path to the file and its MP3 tag information, respectively. Returns a boolean indicating the success of the operation. $result_code = $mp3->send_stream($file,$uri) The send_stream() method generates an ICY (shoutcast) header for the indicated file (given by physical path $file and URI $uri) and streams it to the client. It returns an Apache result code indicating the success of the operation. $boolean = $mp3->download_ok Returns true if downloading files is allowed. $boolean = $mp3->stream_ok Returns true if streaming files is allowed. $boolean = $mp3->check_stream_client Returns true if the module should check the browser/MP3 player for whether it accepts streaming. $boolean = $mp3->is_stream_client Returns true if this MP3 player can accept streaming. Note that this is not a foolproof method because it checks a variety of non-standardized headers and user agent names! $boolean = $mp3->read_mp3_info Returns true if the module should read MP3 info (true by default). $seconds = $mp3->stream_timeout Returns the number of seconds after which streaming should time out. Used for "demo mode". $lines = $mp3->file_list_is_long Returns the number of lines in the MP3 file listing after which the list is considered to be "long". When a long list is encountered, the module places the control buttons at both the top and bottom of the MP3 file table, rather than at the bottom only. This method $html = $mp3->home_label Returns a fragment of HTML to use as the "Home" link in the list of parent directories. $style = $mp3->path_style Returns the style of the list of parent directories. Either "arrows" or "staircase". $path = $mp3->cache_dir Returns the directory for use in caching MP3 tag information $int = $mp3->subdir_columns Returns the number of columns to use in displaying subdirectories (little CD icons). $dir = $mp3->default_dir Returns the base directory used for resolving relative paths in the directories to follow. miscellaneous directories and files The following methods return the values of their corresponding configuration variables, resolved against the base directory, if need be: stylesheet() URI to the stylesheet file parent_icon() URI to the icon to use to move up in directory hierarchy (no longer used) cd_icon URI for the big CD icon printed in the upper left corner cd_list_icon URI for the little CD icons in the subdirectory listing playlist_icon URI for the playlist icon song_icon URI for the music note icons printed for each MP3 file arrow_icon URI for the arrow used in the navigation bar help_url URI of the document to display when user asks for help $boolean = $mp3->skip_directory($dir) This method is called during directory listings. It returns true if the directory should not be displayed. Currently it skips directories beginning with a dot and various source code management directories. You may subclass this to skip over other directories. BUGS ==== Although it is pure Perl, this module relies on an unusual number of compiled modules. Perhaps for this reason, it appears to be sensitive to certain older versions of modules. Can't find Apache::File at run time ----------------------------------- David Wheeler <dwheeler@salon.com> has reported problems relating to Apache::File, in which the module fails to run, complaining that it can't find Apache::File in @INC. This affects Apache/1.3.12 mod_perl/1.24. Others have not yet reported this problem. This can be worked around by replacing all occurrences of Apache::File with IO::File. Random segfaults in httpd children ---------------------------------- Before upgrading to Apache/1.3.6 mod_perl/1.24, I would see random segfaults in the httpd children when using this module. This problem disappeared when I installed a newer mod_perl. If you experience this problem, I have found that one workaround is to load the MP3::Info module at server startup time using the mod_perl perl.startup script made the problem go away. This is an excerpt from my perl.startup file: # the !/usr/local/bin/perl ... use Apache::Registry (); use Apache::Constants(); use MP3::Info; use Apache::MP3; use CGI(); use CGI::Carp (); Can't use -d $r->finfo ---------------------- Versions of mod_perl prior to 1.22 crash when using the idiom -d $r->finfo (or any other idiom). Since there are many older versions still out there, I have replaced $r->finfo with $r->filename and marked their locations in comments. To get increased performance, change back to $r->finfo. Misc ---- In the directory display, the alignment of subdirectory icon with the subdirectory title is a little bit off. I want to move the title a bit lower using some stylesheet magic. Can anyone help? SEE ALSO ======== *Note Apache/MP3/Sorted: Apache/MP3/Sorted,, *Note Apache/MP3/Playlist: Apache/MP3/Playlist,, *Note MP3/Info: MP3/Info,, *Note Apache: Apache, ACKNOWLEDGEMENTS ================ Tim Ayers <tayers@bridge.com> found and fixed a misfeature in the way that playlists were sorted. Chris Nandor identified various bugs in the module and provided patches. AUTHOR ====== Copyright 2000, Lincoln Stein <lstein@cshl.org>. This module is distributed under the same terms as Perl itself. Feel free to use, modify and redistribute it as long as you retain the correct attribution.