NAME
File::Tasks - A set of file tasks to be executed in a directory
SYNOPSIS
# Create a script
my $Script = File::Tasks->new;
# Add some new files
$Script->add( 'Foo' );
DESCRIPTION
File::Tasks allows you to define a set of file tasks to be done to a
local filesystem. There are three basic tasks, Add, Edit, and Remove.
A single File::Tasks object is used to assemble a collection of these
tasks, and then execute them on a new or existing directory somewhere on
the local filesystem.
The File::Tasks will take care of making sure that the task paths are
all compatible with their resulting location, and that the tasks match
the current state of the filesystem.
Once fully verified, it will execute the tasks and make the changes to
the filesystem.
METHODS
new @params
Create and return a new "File::Tasks" object. Takes as argument a number
of parameters in "<Key =" $value>> form.
provider
Provide a custom Data Provider. The passed object must be a
sub-class of File::Tasks::Provider.
Returns a new "File::Tasks" object.
provider
Returns the Provider object for the File::Tasks
ignore
Returns the original "File::Find::Rule" for the files to be ignore
provided to the constructor.
paths
Returns as a sorted list the file paths of all of the Tasks
tasks
Returns all of the Tasks as a list, in the same order as for paths.
task $path
Access a single File::Tasks::Task object by its path
add $path, $source
The "add" method creates an "Add" task and adds it to the File::Tasks.
An Add task creates a new file where no file currently exists. Upon
execution of the File::Tasks, if a file already exists at the location,
execution will fail.
Returns the new File::Tasks::Add object as a convenience. Returns
"undef" if the path clashes, or the source is not valid.
edit $path, $source
The "edit" method creates as "Edit" task and adds it to the File::Tasks.
An Edit task replaces the contents of an existing file. Upon execution
of the File::Tasks, if no file exists the execution will fail.
Returns the File::Tasks::Edit object as a convenience. Returns "undef"
if the path clashes, or the source is not valid.
remove $path
The "remove" method creates a "Remove" task and adds it to the
File::Tasks. A Remove task deletes a file currently on the filesystem.
If no file exists, execution will fail.
Returns the File::Tasks::Remove object as a convenience. Returns "undef"
if the path clashes.
remove_dir $dir [, $Rule ]
The "remove_dir" method is specifically designed to remove an entire
directory. The directory passed as the first argument is scanned using
File::Find::Rule to find all the files in it, and then a series if
"Remove" tasks are created and added based on the relative location of
the files in the existing directory.
A pre-built Rule object can be provided as the second argument to modify
the behaviour of File::Find::Rule when searching for files. In one
example, you might want to add Remove tasks for all the files in a CVS
checkout, without removing the .cvs directories.
# Create the "leave .cvs dirs intact" rule
my $Rule = File::Find::Rule->new;
$Rule = $Rule->or(
$Rule->new->directory->name('.cvs')->prune,
$Rule->new->file
);
# Add the Remove tasks
$Script->remove_dir($dir, $Rule);
Returns the number of Remove tasks added, which may validly be zero. On
error, such as a bad directory, bad second argument, or failed Remove
Task addition, returns "undef".
set $Task
For a File::Tasks::Task object created outside of File::Tasks, the "set"
method attempts to add it to the Script.
Returns the Task object as a convenience, or "undef" on error.
clashes $path
The "clashes" method is used to determine if a path clashes with an
existing Task in the File::Tasks object. Generally this is because a
file already exists for a directory you want to add, or vica versa.
Returns true if the path clashes, or false if not.
test $dir
The "test" method does a complete dry run of the execution of the
File::Tasks object. This includes:
- Ensuring that no paths clash
- Checking that all files that should exist do
- Checking that all files that shouldn't exist don't
- Checking we have the correct permissions
Returns true if the test run was successful, or "undef" otherwise.
execute $dir
Executes the File::Tasks. This will create, modify or remove files as
described in the Tasks.
Due to the delicate and somewhat complex nature of the installation, you
almost certainly will want to do a test run with "<-"test($dir)>> before
the live call.
Returns true if completed successfully, or "undef" otherwise.
overlay $Under, $Over
To keep complexity down, a great way of generating File::Tasks objects
that will "overwrite" a previous installation is to do it in two parts.
# Create a script to remove the old installation
my $Old = File::Tasks->new;
$Old->remove_dir($dir);
# Script for a fresh install spat out by some module
my $Install = My::Module->build->Script;
# Overlay the new install over the old removal to create
# a combined script that will "shift" the current files as needed.
my $Script = $Old->overlay($Install);
Where this gets really cool is that if the new file is the same as the
old file, the Task will be optimised away.
This means that if the underlying data for a process changes, and you
rerun a generator of some sort, the only output files that are touched
are the ones that will actually change as a result of the underlying
data changing.
Given two File::Tasks objects, will create and return a new Script that
represents the combination of the two. Returns "undef" on error.
The + operator is also effectively overloaded to this method
# The explicit way
my $Script = $Old->overlay($Install);
# Via the overload
my $Script = $Old + $Install;
TO DO
- Much more detailed unit testing
- Add various caching options
SUPPORT
Bugs should be reported via the CPAN bug tracker at
<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=File-Tasks>
For other issues, contact the author.
AUTHOR
Adam Kennedy <adamk@cpan.org>, <http://ali.as/>
COPYRIGHT
Copyright 2005, 2006 Adam Kennedy.
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.