NAME Archive::Builder - File generation and archiving framework SYNOPSIS # Make a builder with one section, and some files my $Builder = Archive::Builder->new(); my $Section = $Builder->new_section( 'html' ); $Section->add_file( 'one.html', 'string', qq~ Hello World! ~ ); $Section->add_file( 'two.html', 'file', './source/file.html' ); $Section->add_file( 'three.html', 'Custom::function', @args ); # Generate and save to disk $Builder->save( './somewhere' ); # Create an zip file from it and save it. my $Archive = $Builder->archive( 'zip' ). $Archive->save( '' ); # Create a tar.gz file of just one section my $Tar = $Section->archive( 'tar.gz' ); DESCRIPTION Perl is often used for applications that generate large numbers of files, and Archive::Builder is designed to assist in these sorts of tasks. It provides a framework for defining a set of files, and how they will be generated, and a series of methods for turning them into an Archive of varying types, or saving directly to disk. Structure Each "Archive::Builder" object consists of one or more "Archive::Builder::Section"s, which contain one or more "Archive::Builder::File"s. Each of these files know their location within the section, and are given a generation function, with a set of arguments specific to each generator. Some simple generators are provided built-in, or you can provide an function name as the generator. Generating Archives Once a Archive::Builder is fully defined, you can "save" it to disk, or get an "archive", containing the generated files, in one of several formats. You can also "save" and get the "archive" any of the individual sections within the builder. During the generation process for an entire "Archive::Builder" a subdirectory is created for each section matching the name of the section. So, for a builder with a Section name 'one', containing a single file 'two.txt', and a section 'three', containing files 'four.html' and 'five.dat', the following file structure would result one/two.txt three/four.html three/five.dat Caching Caching is dont of the generated files on a per-file basis. Two calls to the "content()" method of an "Archive::Builder::File" object will only result in the file being generated once, and the same contents returned twice. Generation on Demand Caveats During an output action, such as a "save()" or "archive()" method call, the contents of each file are generated only as needed. This means that if the generation of a file fails, an action may have already been taken ( especially in the case of "save()", where you may end up with only part of the files written to disk. Some procedures to address these limitations will be added as the module evolves. METHODS The methods for the three main classes involved in generation trees, "Archive::Builder", "Archive::Builder::Section" and "Archive::Builder::File" are documented below. For the archive handlers the builders generate, see Archive::Builder::Archive. For information on the built-in generators, and how to write your own generators, see Archive::Builder::Generators. Common Error Handlers Errors from any object of any type below Archive::Builder are set in the global $Archive::Builder::errstr variable. They can also be retrieved from the "errstr()" method called on any object. Archive::Builder new() The "new()" constructor takes no arguments, and returns a new "Archive::Builder" object. add_section( Archive::Builder::Section ) The "add_section" method takes as an argument an "Archive::Builder::Section" object, and adds it to the builder. Returns true if the section is added successfully. Returns undef on error, for example if another Section with the same name has already been added. new_section( name ) Creates a new "Archive::Builder::Section" object with the name provided, and immediately adds it to the builder. Returns the new Section object on success. Returns undef on error. section( name ) Finds and returns a "Archive::Builder::Section" object with the provided name within the builder and returns it. Returns undef if passed name does not exist. sections() Returns a hash containing all the sections, indexed by name. Returns 0 if no sections have been created in the builder. section_list() Returns all the sections in the builder as a list, sorted by section name. Returns a null list "()" if no sections are defined in the builder. remove_section( name ) Removes a section of a given name from the builder, if it exists. Returns "undef" if no such section exists. file_count() Returns the total number of files in ass sections in the builder save( directory ) Generates the file tree for the entire builder and attempts to save it below a given directory. The passed directory does not have to exist, it will be created on demand. Returns true if all files were generated and saved successfully. Returns "undef" if an error occurs, or the directory is bad. delete() Because of the structure used to support the parent methods, you should probably explicitly delete Builds when you are done with them to avoid memory leaks due to circular dependencies. The "delete" method always returns true. archive( type ) Creates a handle to an archive of a specified type related to the builder. Types can only be used if the modules that support them are installed. The following types are supported, and their prerequisites are listed. zip - Archive::Zip tar - Archive::Tar tar.gz - Archive::Tar tgz - Archive::Tar The tar.gz and tgz are aliases that produce the same thing with a different file extension. The "archive" method only returns a "Archive::Builder::Archive" handle to the object, not the object itself. Also, the files are not generated at the time that the archive is created, so generation errors cannot be guarenteed to have occurred by this time. To save or otherwise act on the archive, see the Archive::Builder::Archive section below. Archive::Builder::Section new( name ) Creates a new "Archive::Builder::Section" object of a given name. Although meant to be used in an "Archive::Builder" object, they can still be used effectively standalone, as they have both "save" and "archive" methods. Returns undef is an invalid section name is given. A section name must contain only word ( \w ) characters and be 1 to 31 characters long. As a side note, the reason that Sections exist at all is so that Builders can be defined containing multiple sections, where the sections will be saved to different locations, but should still be passed around as a single entity. name() Returns the name of the Section. path( [ path ] ) When used within the context of a Builder object, and set to the same value as the section's name by default, this method returns the path below the Builder root that will be used, or if passed a relative path, will set the path to a new value. You are not likely to need this, as in general, the same value will suffice for both the name and path. Builder() If the Section has been added to a Builder, the "Builder" method will return it. Returns a "Archive::Builder" object if added, or "undef" if not. add_file( Archive::Builder::File ) Adds an existing "Archive::Builder::File" object to the section. Returns true on success. Returns "undef" on error, or if the path of the file clashes with an existing file in the Section. This could happen if you try to add a file with the same name, of if your path contains a directory that is already in the Section as a file. For example, the two files could not exist in the same Section. first/second first/second/third Creation of the directory first/second would be blocked by the existing file first/second ( or vica versa ). This issue is caught for you now, rather than wait until we are halfway through writing the files to disk to find out. new_file( path, generator [, arguments ] ) Creates a new file, using the arguments provided, and immediately adds it to the current section. See the "new" method for Archive::Builder::File below for more details on the arguments. Returns true if the file is created and added successfuly. Returns "undef" if an error occurs during either the creation or addition of the file. file( path ) Finds the "Archive::Builder::File" object with the given path and returns it. Returns undef if no such file exists. files() Returns a reference to a hash containing all of the files objects, keyed by their paths. Returns 0 if no files exist within the section. file_list() Returns a list of all the file objects, sorted by path. Returns a null array "()" if no files exist within the section. remove_file( path ) Removes the file object with the given path from the section. Returns "undef" if no such path exists within the section. file_count() Returns the number of files contained in the section save( directory ) The "save()" method works the same as the "Archive::Builder" "save" method, generating the files and saving them below the directory provided. Again, the directory is created on demand. Returns "undef" if an error during generation or saving occurs. delete() The "delete" method deletes a Section, removing it from it's parent Builder if applicable, and removing all child Files from the Section. Always returns true. archive( type ) As for the "Archive::Builder" "acrhive" method, creates an archive handle of the given type. Returns a "Archive::Builder::Archive" object on success. Returns "undef" on error. Archive::Builder::File new( path, generator [, arguments ] ) Creates a new "Archive::Builder::File" object and returns it. This method is not normally used directly, with the "Archive::Builder::Section" method "new_file()" being more typically used. The path argument should be a valid looking relative path. That is, it cannot start with /. For safety, the use of escaping slashes and relative '..' paths are restricted for safety. The generator should be a string containing the name of the function to be used to generate the file contents. A check will be done to ensure that the module containing the function is installed, although the existance of the function itself will not be tested. For example, for the generator function "Foo::Bar::makeme", a test to make sure "Foo::Bar" is installed will be done. To specify a function in the the main package ( say in a script ), the format "main::function" MUST be used. A generator value that does not contain a package seperator will be assumed to be one of the default generators. The list of default generators, and instructions on how to write your own generators, are in the Archive::Builder::Generators documentation. Anything passed after the generator are assumed to be arguments to the generator function, and will be stored and passed as needed. Note that the arguments are not copied or cloned, so any objects passed as arguments and later modified, will be generated using the modified values. This is considered a feature. If you need to freeze a copy of the object for the generation, you are recommended to Clone it before passing. path() Returns the path for the file. This cannot be changed after creation. generator() Returns the generator for the file. This cannot be changed after creation arguments() Returns a reference to an array containing the arguments to be passed to the generator, or 0 if there are no arguments. The list of arguments cannot be changed after creation ( although of course objects passed can be changed outside the scope of this API ). binary() This method will analyse the file contents ( generating if needed ) to determine if the file is a binary file. While not 100% accurate, it should be good enough for most situations. executable() Calling this method will add a hint to the file that it should be considered as an executable file, should the need arise. This is most likely used in situations where permissions need to be set after generation. Section() If added to a Section, the "Section" method returns the Section to which we have been added. Returns a Archive::Builder::Section object if the File is added to one, or "undef" if not. contents() Generates and returns the contents of the file as a scalar reference. Returns "undef" if a generation error occurs. save( filename ) Bypassing the normal generation process and path name, the "save" method allows you to generate a single file object and save it to a specific filename. Any directories need to write the file will be created on demand. Returns "undef" if a generation permissions error occurs. delete() If added to a Section, the "delete" method allows us to remove and delete the file from the parent Section. Always returns true. TODO Better control over caching, more archive types, pre-generation testing. SUPPORT Contact the author AUTHOR Adam Kennedy ( maintainer ) SEE ALSO Archive::Builder::Archive, Archive::Builder::Generators, Archive::Tar, Archive::Zip. COPYRIGHT Copyright (c) 2002 Adam Kennedy. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of the license can be found in the LICENSE file included with this module.