@subsection Goals

This section exists to organize files related to @code{path}
functiontionality.  The @code{path} functionality standardizes
movement, syncronization, branching, tagging, and general file
maintainance inside the repository. 

@subsection Description

@emph{''CentOS like trees, has roots, trunk, branches, leaves and
flowers.  Day by day they work together in freedom, ruled by the laws
of nature and open standards, to show the beauty of its existence.''}

@subsubsection Repository layout

The repository layout describes organization of files and directories
inside the repository. The repository layout provides the standard
backend required for automation scripts to work correctly. If such
layout changes unexpectedly, automation scripts may confuse themselves
and stop doing what we expect from them to do.

As convenction, inside CentOS Artwork Repository, we organize files
and directories related to CentOS corporate visual identity under
three top level directories named: @file{trunk/}, @file{branches/},
and @file{tags/}. 

The @file{trunk/} directory (@pxref{Filesystem trunk}) organizes the main
development line of CentOS corporate visual identity. Inside
@file{trunk/} directory structure, the CentOS corporate visual
identity concepts are implemented using directories.  There is one
directory level for each relevant concept inside the repository. The
@file{trunk/} directory structure is mainly used to perform
development tasks related to CentOS corporate visual identity.

The @file{branches/} directory () oranizes
parallel development lines to @file{trunk/} directory. The
@file{branches/} directory is used to set points in time where
develpment lines are devided one from another taking separte and
idependent lives that share a common past from the point they were
devided on. The @file{branches/} directory is mainly used to perform
quality assurance tasks related to CentOS corporate visual identity.

The @file{tags/} directory (@pxref{Filesystem tags}) organizes parallel frozen
lines to @file{branches/} directory.  The parallel frozen lines are
immutable, nothing change inside them once they has been created.  The
@file{tags/} directory is mainly used to publish final releases of
CentOS corporate visual identity.

The CentOS Artwork Repository layout is firmly grounded on a
Subversion base.  Subversion (@url{http://subversion.tigris.org}) is a
version control system, which allows you to keep old versions of files
and directories (usually source code), keep a log of who, when, and
why changes occurred, etc., like CVS, RCS or SCCS.  Subversion keeps a
single copy of the master sources.  This copy  is called the source
``repository''; it contains all the information to permit extracting
previous versions of those files at any time.

@subsubsection Repository name convenctions

Repository name convenctions help us to maintain consistency of names
inside the repository.

Repository name convenctions are applied to files and directories
inside the repository layout. As convenction, inside the repository
layout, file names are all written in lowercase
(@samp{01-welcome.png}, @samp{splash.png}, @samp{anaconda_header.png},
etc.) and directory names are all written capitalized (e.g.,
@samp{Identity}, @samp{Themes}, @samp{Motifs}, @samp{TreeFlower},
etc.).

Repository name convenctions are implemented inside the
@code{cli_getRepoName} function of @file{centos-art.sh} script. With
@code{cli_getRepoName} function we reduce the amount of commands and
convenctions to remember, concentrating them in just one single place
to look for fixes and improvements.

@subsubsection Repository work flow

Repository work flow describes the steps and time intervals used to
produce CentOS corporate visual identity inside CentOS Artwork
Repository.  

To illustrate repository work flow let's consider themes' development
cycle. 

Initially, we start working themes on their trunk development line
(e.g., @file{trunk/Identity/Themes/Motifs/TreeFlower/}), here we
organize information that cannot be produced automatically (i.e.,
background images, concepts, color information, screenshots, etc.).

Later, when theme trunk development line is considered ``ready'' for
implementation (e.g.,  all required backgrounds have been designed),
we create a branch for it (e.g.,
@file{branches/Identity/Themes/Motifs/TreeFlower/1/}).  Once the
branch has been created, we forget that branch and continue working
the trunk development line while others (e.g., an artwork quality
assurance team) test the new branch for tunning it up. 

Once the branch has been tunned up, and considered ``ready'' for
release, it is freezed under @file{tags/} directory (e.g.,
@file{tags/Identity/Themes/Motifs/TreeFower/1.0/}) for packagers,
webmasters, promoters, and anyone who needs images from that CentOS
theme the tag was created for.

Both branches and tags, inside CentOS Artwork Repository, use
numerical values to identify themselves under the same location.
Branches start at one (i.e., @samp{1}) and increment one unit for each
branch created from the same trunk development line.  Tags start at
zero (i.e., @samp{0}) and increment one unit for each tag created from
the same branch development line.

@quotation
@strong{Convenction} Do not freeze trunk development lines using tags
directly.  If you think you need to freeze a trunk development line,
create a branch for it and then freeze that branch instead.
@end quotation

The trunk development line may introduce problems we cannot see
immediatly. Certainly, the high changable nature of trunk development
line complicates finding and fixing such problems. On the other hand,
the branched development lines provide a more predictable area where
only fixes/corrections to current content are commited up to
repository. 

If others find and fix bugs inside the branched development line, we
could merge such changes/experiences back to trunk development line
(not visversa) in order for future branches, created from trunk, to
benefit.

Time intervals used to create branches and tags may vary, just as
different needs may arrive. For example, consider the release schema
of CentOS distribution: one major release every 2 years, security
updates every 6 months, support for 7 years long. Each time a CentOS
distribution is released, specially if it is a major release, there is
a theme need in order to cover CentOS distribution artwork
requirements. At this point, is where CentOS Artwork Repository comes
up to scene. 

Before releasing a new major release of CentOS distribution we create
a branch for one of several theme development lines available inside
the CentOS Artwork Repository, perform quality assurance on it, and
later, freeze that branch using tags. Once a the theme branch has been
frozen (under @file{tags/} directory), CentOS Packagers (the persons
whom build CentOS distribution) can use that frozen branch as source
location to fulfill CentOS distribution artwork needs. The same
applies to CentOS Webmasters (the persons whom build CentOS websites),
and any other visual manifestation required by the project.

@subsubsection Parallel directories

Inside CentOS Artwork Repository, parallel directories are simple
directory entries built from a common parent directory and placed in a
location different to that, the common parent directory is placed on.
Parallel directories are useful to create branches, tags,
translations, documentation, pre-rendering configuration script, and
similar directory structures.

Parallel directories take their structure from one unique parent
directory. Inside CentOS Artwork Repository, this unique parent
directory is under @file{trunk/Identity} location.  The
@file{trunk/Identity} location must be considered the reference for
whatever information you plan to create inside the repository.

In some circumstances, parallel directories may be created removing
uncommon information from their paths. Uncommon path information
refers to those directory levels in the path which are not common for
other parallel directories.  For example, when rendering
@file{trunk/Identity/Themes/Motifs/TreeFlower/Distro} directory
structure, the @file{centos-art.sh} script removes the
@file{Motifs/TreeFlower/} directory levels from path, in order to
build the parallel directory used to retrived translations, and
pre-rendering configuration scripts required by @code{render}
functionality.

Another example of parallel directory is the documentation structure
created by @code{manual} functionality. This time,
@file{centos-art.sh} script uses parallel directory information with
uncommon directory levels to build the documentation entry required by
Texinfo documentation system, inside the repository.

Othertimes, parallel directories may add uncommon information to their
paths. This is the case we use to create branches and tags. When we
create branches and tags, a numerical identifier is added to parallel
directory structure path. The place where the numerical identifier is
set on is relevant to corporate visual identity structure and should
be carefully considered where it will be.

When one parent directory changes, all their related parallel
directories need to be changed too. This is required in order for
parallel directories to retain their relation with the parent
directory structure.  In the other hand, parallel directories should
never be modified under no reason but to satisfy the relation to their
parent directory structure.  Liberal change of parallel directories
may suppresses the conceptual idea they were initially created for;
and certainly, things may stop working the way they should do.

@subsubsection Syncronizing path information

Parallel directories are very useful to keep repository organized but
introduce some complications.  For instance, consider what would
happen to functionalities like @code{manual} (@samp{trunk Scripts Bash
Functions Manual}) that rely on parent directory structures to create
documentation entries (using parallel directory structures) if one of
those parent directory structures suddenly changes after the
documentation entry has been already created for it? 

In such cases, functionalities like @code{manual} may confuse
themselves if path information is not updated to reflect the relation
with its parent directory.  Such functionalities work with parent
directory structure as reference; if a parent directory changes, the
functionalities dont't even note it because they work with the last
parent directory structure available in the repository, no matter what
it is. 

In the specific case of documentation (the @code{manual}
functionality), the problem mentioned above provokes that older parent
directories, already documented, remain inside documentation directory
structures as long as you get your hands into the documentation
directory structure (@file{trunk/Manuals}) and change what must be
changed to match the new parent directory structure.

There is no immediate way for @code{manual}, and similar
functionalities that use parent directories as reference, to know when
and how directory movements take place inside the repository. Such
information is available only when the file movement itself takes
place inside the repository. So, is there, at the moment of moving
files, when we need to syncronize parallel directories with their
unique parent directory structure.

@quotation
@strong{Warning} There is not support for URL reference inside
@file{centos-art.sh} script.  The @file{centos-art.sh} script is
designed to work with local files inside the working copy only.
@end quotation

As CentOS Artwork Repository is built over a version control system,
file movements inside the repository are considered repository
changes. In order for these repository changes to be versioned, we
need to, firstly, add changes into the version control system, commit
them, and later, perform movement actions using version control system
commands. This configuration makes possible for everyone to know about
changes details inside the repository; and if needed, revert or update
them back to a previous revision.

Finally, once all path information has been corrected, it is time to
take care of information inside the files. For instance, considere
what would happen if you make a reference to a documentation node, and
later the documentation node you refere to is deleted. That would make
Texinfo to produce error messages at export time. So, the
@file{centos-art.sh} script needs to know when such changes happen, in
a way they could be noted and handled without producing errors.

@subsubsection What is the right place to store it?

Occasionly, you may find that new corporate visual identity components
need to be added to the repository. If that is your case, the first
question you need to ask yourself, before start to create directories
blindly all over, is: What is the right place to store it?

The CentOS Community different free support vains (see:
@url{http://wiki.centos.org/GettingHelp}) are the best place to find
answers to your question, but going there with hands empty is not good
idea. It may give the impression you don't really care about. Instead,
consider the following suggestions to find your own comprehension and
so, make your propositions based on it.

When we are looking for the correct place to store new files, to bear
in mind the corporate visual identity structure used inside the CentOS
Artwork Repository (@pxref{Filesystem trunk Identity}) would be probaly the best
advice we could offer, the rest is just matter of choosing appropriate
names.  To illustrate this desition process let's consider the
@file{trunk/Identity/Themes/Motifs/TreeFlower} directory as example.
It is the trunk development line of @emph{TreeFlower} artistic motif.
Artistic motifs are considered part of themes, which in turn are
considered part of CentOS corporate visual identity.

When building parent directory structures, you may find that reaching
an acceptable location may take some time, and as it uses to happen
most of time; once you've find it, that may be not a definite
solution.  There are many concepts that you need to play with, in
order to find a result that match the conceptual idea you try to
implement in the new directory location. To know which these concepts
are, split the location in words and read its documentation entry from
less specific to more specific.

For example, the @file{trunk/Identity/Themes/Motifs/TreeFlower}
location evolved through several months of contant work and there is
no certain it won't change in the future, even it fixes quite well the
concept we are trying to implement.  The concepts used in
@file{trunk/Identity/Themes/Distro/Motifs/TreeFlower} location are
described in the following commands, respectively:

@verbatim
centos-art manual --read=turnk/
centos-art manual --read=turnk/Identity/
centos-art manual --read=turnk/Identity/Themes/
centos-art manual --read=turnk/Identity/Themes/Motifs/
centos-art manual --read=turnk/Identity/Themes/Motifs/TreeFlower/
@end verbatim

Other location concepts can be found similary as we did above, just
change the location we used above by the one you are trying to know
concepts for.

@subsection Usage

@table @command
@item centos-art path --copy='SRC' --to='DST'

Copy @option{SRC} to @option{DST} and schedule @option{DST} for
addition (with history).  In this command, @file{SRC} and @file{DST}
are both working copy (WC) entries.

@item centos-art path --delete='SRC'

Delete @option{DST}. In order for this command to work the file or
directory you intend to delete should be under version control first.
In this command, @file{SRC} is a working copy (WC) entry.  

@end table

@subsection See also

@menu
* Filesystem trunk Scripts Bash::
@comment --- Removed(* Filesystem trunk Scripts Bash Functions::) ---
@end menu