@subsection Goals

Organize scalable vector graphics (svg) to help describe the CentOS

web environment.

@subsection The CentOS web environment

Inside CentOS corporate identity, the CentOS web environment is

considered a promotion component. The CentOS web environment is formed

by a central web application ---to cover base needs (e.g., per-major

release information like release notes, lifetime, downloads,

documentation, support, security advisories, bugs, etc.)--- and many

different free web applications ---to cover specific needs (e.g.,

wiki, mailing lists, etc.)---. 

The CentOS web environment is addressed to solve the following issues:

@itemize

@item One unique name and one unique visual style to all web

applications used inside the web environment.

@item One-step navigation to web applications inside the environment.

@item High degree of customization to change the visual style of all

web applications with few changes (e.g, updating just two or three

images plus common style sheet [CSS] definitions).

@end itemize

The CentOS project is attached to a monolithic corporate visual

identity (@pxref{trunk Identity}), where all visual manifestations

have one unique name and one unique visual style. This way, the CentOS

web environment has one unique name (the CentOS brand) and one unique

visual style (the CentOS default theme) for all its visual

manifestations, the web applications in this case.

Since a maintainance point of view, achiving the one unique visual

style inside CentOS web environment is not a simple task. The CentOS

web environment is built upon many different web applications which

have different visual styles and different internal ways to customize

their own visual styles. For example: MoinMoin, the web application

used to support the CentOS wiki (@url{http://wiki.centos.org/}) is

highly customizable but Mailman (in its 2.x.x serie), the web

application used to support the CentOS mailing list, doesn't

support@footnote{The theme support of Mailman may be introduced in

mailman-3.x.x release.} a customization system that separates

presentation from logic, similar to that used by MoinMoin.

This visual style diversity complicates our goal of one unique visual

style for all web applications. So, if we want one unique visual style

for all web applications used, it is innevitable to modify the web

applications in order to implement the CentOS one unique visual style

customization in them. Direct modification of upstream applications is

not convenient because upstream applications come with their one

visual style and administrators take the risk of loosing all

customization changes the next time the application be updated (since

not all upstream web applications, used in CentOS web environment,

separate presentation from logic).

To solve the ``one unique visual style'' issue, installation and

actualization of web applications ---used inside CentOS web

environment--- need to be independent from upstream web applications

development line; in a way that CentOS web environment administrators

can install and update web applications freely without risk of loosing

the one unique visual style customization changes. 

At the surface of this issue we can see the need of one specific yum

repository to store CentOS web environment customized web applications.

@subsubsection Design model (without ads)

@subsubsection Design model (with ads)

@subsubsection HTML definitions

@subsubsection Controlling visual style

Inside CentOS web environment, the visual style is controlled by the

following compenents:

@table @strong

@item Webenv header background

@verbatim

trunk/Identity/Themes/Motifs/$THEME/Backgrounds/Img/1024x250.png

@end verbatim

@item CSS definitions

@verbatim

trunk/Identity/Themes/Models/Default/Promo/Web/CSS/stylesheet.css

@end verbatim

@end table

@subsubsection Producing visual style

The visual style of CentOS web environment is defined in the following

files:

@verbatim

trunk/Identity/Themes/Motifs/$THEME/Backgrounds/Xcf/1024x250.xcf

trunk/Identity/Themes/Motifs/$THEME/Backgrounds/Img/1024x250.png

trunk/Identity/Themes/Motifs/$THEME/Backgrounds/Img/1024x250-bg.png

trunk/Identity/Themes/Motifs/$THEME/Backgrounds/Tpl/1024x250.svg

@end verbatim

As graphic designer you use @file{1024x250.xcf} file to produce

@file{1024x250-bg.png} file. Later, inside @file{1024x250.svg} file,

you use the @file{1024x250-bg.png} file as background layer to draw

your vectorial design. When you consider you artwork ready, use the

@command{centos-art.sh} script, as described below, to produce the

visual style controller images of CentOS web environment.

@verbatim

centos-art render --entry=trunk/Identity/Themes/Motifs/$THEME/Backgrounds --filter='1024x250'

@end verbatim

Once you have rendered required image files, changing the visual style

of CentOS web environment is a matter of replacing old image files

with new ones, inside webenv repository file system structure. The

visual style changes will take effect the next time customization line

of CentOS web applications be packaged, uploded, and installed from

[webenv] or [webenv-test] repositories.

@subsubsection Navigation

Inside CentOS web environment, the one-step navegation between web

applications is addressed using the web environment navigation bar.

The web environment navigation bar contains links to main applications

and is always visible no matter where you are inside the web

environment.

@subsubsection Development and release cycle

The CentOS web environment development and relase cycle is described

below: 

@table @strong

@item Download

The first action is download the source code of web applications we

want to use inside CentOS web environment.

@quotation

@strong{Important} The source location from which web application are

downloaded is very important. Use SRPMs from CentOS @strong{[base]}

and @strong{[updates]} repositories as first choise, and third party

repositories (e.g. RPMForge, EPEL, etc.) as last resource.

@end quotation

@item Prepare 

Once web application source code has been downloaded, our duty is

organize its files inside @samp{webenv} version controlled repository.

When preparing the structure keep in mind that different web

applications have different visual styles, and also different ways to

implement it. A convenient way to organize the file system structure

would be create one development line for each web application we use

inside CentOS web environment. For example, consider the following

file system structure:

@verbatim

https://projects.centos.org/svn/webenv/trunk/

|-- WebApp1/

|   |-- Sources/

|   |   `-- webapp1-0.0.1/

|   |-- Rpms/

|   |   `-- webapp1-0.0.1.rpm

|   |-- Srpms/

|   |   `-- webapp1-0.0.1.srpm

|   `-- Specs/

|       `-- webapp1-0.0.1.spec

|-- WebApp2/

`-- WebAppN/

@end verbatim

@item Customize

Once web applications have been organized inside the version

controlled repository file system, use subversion to create the CentOS

customization development line of web applications source code.  For

example, using the above file system structure, you can create the

customization development line of @file{webapp1-0.0.1/} with the

following command:

@verbatim

svn cp trunk/WebApp1/Sources/webapp1-0.0.1 trunk/WebApp1/Sources/webapp1-0.0.1-webenv

@end verbatim

The command above creates the following structure:

@verbatim

https://projects.centos.org/svn/webenv/trunk/

|-- WebApp1/

|   |-- Sources/

|   |   |-- webapp1-0.0.1/

|   |   `-- webapp1-0.0.1-webenv/

|   |-- Rpms/

|   |   `-- webapp1-0.0.1.rpm

|   |-- Srpms/

|   |   `-- webapp1-0.0.1.srpm

|   `-- Specs/

|       `-- webapp1-0.0.1.spec

|-- WebApp2/

`-- WebAppN/

@end verbatim

In the above structure, the @file{webapp1-0.0.1-webenv/} directory is

the place where you customize the visual style of

@file{webapp1-0.0.1/} web application. 

@quotation

@strong{Tip} Use the @command{diff} command of Subversion between

CentOS customization and upstream development lines to know what you

are changing exactly.

@end quotation

@item Build packages

When web application has been customized, build the web application

RPM and SRPM using the source location with @samp{-webenv} prefix. 

@verbatim

https://projects.centos.org/svn/webenv/trunk/

|-- WebApp1/

|   |-- Sources/

|   |   |-- webapp1-0.0.1/

|   |   `-- webapp1-0.0.1-webenv/

|   |-- Rpms/

|   |   |-- webapp1-0.0.1.rpm

|   |   `-- webapp1-0.0.1-webenv.rpm

|   |-- Srpms/

|   |   |-- webapp1-0.0.1.srpm

|   |   `-- webapp1-0.0.1-webenv.srpm

|   `-- Specs/

|       |-- webapp1-0.0.1.spec

|       `-- webapp1-0.0.1-webenv.spec

|-- WebApp2/

`-- WebAppN/

@end verbatim

@item Release for testing

When the customized web application has been packaged, make packages

available for testing and quality assurance. This can be achives using

a [webenv-test] yum repository. 

@quotation

@strong{Note} The [webenv-test] repository is not shipped inside

CentOS distribution default yum configuraiton. In order to use

[webenv-test] repository you need to configure it first.

@end quotation

If some problem is found to install/update/use the customized version

of web application, the problem is notified somewhere (a bugtracker

maybe) and the customization face is repated in order to fix the

problem. To release the new package add a number after @samp{-webenv}

prefix. For example, if some problem is found in

@file{webapp1-0.0.1-webenv.rpm}, when it be fixed the new package will

be named @file{webapp1-0.0.1-webenv-1.rpm}. If a problem is found in

@file{webapp1-0.0.1-webenv-1.rpm}, when it be fixed the new package

will be named @file{webapp1-0.0.1-webenv-2.rpm}, and so on.

The ``customization --- release for testing'' process is repeated

until CentOS quality assurance team considers the package is ready for

production.

@item Release for production

When customized web application packages are considered ready for

production they are moved from [webenv-test] to [webenv] repository.

This action is commited by CentOS quality assurance team.

@quotation

@strong{Note} The [webenv] repository is not shipped inside CentOS

distribution default yum configuraiton. In order to use [webenv]

repository you need to configure it first.

@end quotation

@end table

@subsubsection The [webenv-test] repository

@verbatim

/etc/yum.repos.d/CentOS-Webenv-test.repo

@end verbatim

@verbatim

[webenv-test]

name=CentOS-$releasever - Webenv-test

mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=webenv-test

#baseurl=http://mirror.centos.org/centos/$releasever/webenv-test/$basearch/

gpgcheck=1

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-$releasever

enabled=1

priority=10

@end verbatim

@subsubsection The [webenv] repository

@verbatim

/etc/yum.repos.d/CentOS-Webenv.repo

@end verbatim

@verbatim

[webenv]

name=CentOS-$releasever - Webenv

mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=webenv

#baseurl=http://mirror.centos.org/centos/$releasever/webenv/$basearch/

gpgcheck=1

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-$releasever

enabled=1

priority=10

@end verbatim

@subsubsection Priority configuration

Both [webenv] and [webenv-test] repositories update packages inside

CentOS [base] and CentOS [updates] repositories.

@subsection Usage

@itemize

@item ...

@end itemize

@subsection See also

@menu

* trunk Identity Models Img Promo Web::

@end menu