© 2011, Inventium Systems♣ dool.in

Version Control for the Uninitiated

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Tuesday, May 31, 20116:00 PM

Automattic Lounge711 The Embarcadero San Francisco, CA

WordPress Out Of (version) Control

A presentation by David M. Doolin

for

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© 2011, Inventium Systems♣ dool.in

Bona Fides

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• Who am I?

• Consulting: Interdisciplinary science and engineering software development.

• Inventium Systems: hibernating.

• Website In A Weekend: Pivoting out of internet-space into local-space; working with Tech Liminal, Oakland.

• Landing page: ♣ dool.in

I’ve used version control, starting with Concurrent Version System (CVS), since 1997. I’ve operated my own CVS repository, and I manage several remotely hosted Subversion (SVN) repositories. I have too many projects on Github.

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Quick overview

• What is version control?

• Why you need version control.

• Version control tools Subversion and Git.

• Learning version control.

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All this in 12 minutes or less!

Disclaimer: this presentation was designed for entertainment purposes only, and abounds in vague generalizations, spurious analogies and metaphors which don’t. Use common sense. Verify the information in this presentation from original sources. Do not cite. Thank you.

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© 2011, Inventium Systems♣ dool.in

What is version control?

• A suite of software methodologies.

• Keeps track of changes in files. Forever.

• Promotes collaboration between people across time and space.

• A philosophy for software engineering.

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IMPORTANT: Version control is its own thing

No metaphor, analogy, figure of speech, long winded explanation or slide deck can adequately convey modern version control. You have to do it for yourself.

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Almost 40 years of version control...

1974: Source Code Control System (SCCS). (Written in SNOBOL4!)

1982: Revision Control System (RCS).

1986: Concurrent Version System, (CVS).

2000: Subversion

2005: Git

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When I first looked in to this version control thing, I asked a Real Hacker “Which one, CVS or SCCS, should I learn?”

His reply: “Learn both, then choose for yourself.”

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Why use version control?

• Collaboration with yourself & others across time.

• Collaboration with yourself & others across space.

• Automatic revisioning. You don’t have to dream up (and remember) some hair-brained scheme for organizing revisions of all your files. (“What was the name of that last file?”)

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"It's a good idea." - Sarah Allen

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Version Control - What you need to know

• Version control is leverage for collaboration. People can easily work separated by geography and time zone.

• Leverage works 2 ways...

• Positive leverage: A good team becomes excellent. An excellent team becomes phenomenal.

• Negative leverage: Teams with problems may find those problems getting worse via version control.

• Communication is key: Version control enhances collaborator’s ability to communicate.

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Version control does NOT replace communicationVersion control is not magic pixie dust.

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(CVS) Subversion at-a-glance

• CVS is sort of like C, Which makes Subversion (“a better CVS”) sort of like C++.

• SVN: Use for any text or binary file: LaTeX, WordPress source code, images, this presentation, &c.

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Subversion operates from a centralized repository

http://core.trac.wordpress.org/browser

Beau Pete Ma.tt

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© 2011, Inventium Systems♣ dool.in

Git at-a-glance

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© 2011, Inventium Systems♣ dool.in

Git after your first week

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Unicorns courtesy of Cornify

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© 2011, Inventium Systems♣ dool.in

Jazz lover’s guide to Git versus SVN

• SVN Closed hole flute: Easier to play, sound quality good. Not as cool.

• Git Open hole flute: Harder to play, more flexible (microtones, glissados, etc), sound quality superb. Ineffably cooler.

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“Yes, but how does git feel...?”

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Centralized versus distributed repository

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Image courtesy Coaching to Greatness

Git like distributed cans of worms

SVN root

MeYouMa.tt

You

Me

Ma.tt

Beau

Pete

SVN like the mighty oak

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© 2011, Inventium Systems♣ dool.in

Some pros and cons

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Pros Cons

SVN

• Branching (subtree checkout) remotely is easier.

• Easier to organize unrelated projects.• Handles large numbers of unrelated

projects with ease.• Only commit branch you’re working on.

• Global commits.• Centralized repository.• More prone to conflicts.• Easier to bork local checkout.

Git

• Local commits; reduces conflicts.• Deployment can be trivial, host git repo on

server, commit and push. Eliminates rsync.• Handles large complicated projects with

ease. (Designed for Linux kernel dev.)• Nacin, Jaquith, Mall, etc.

• Project promiscuity.• Must commit whole tree.• Difficult to check out subtree

(this is a problem for WP theme and plugin development).

• Cannot commit stub (empty) directory.

SVN evolved. Git was designed.

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Git Project Proliferation (not that cute)

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Git’s distributed repository model can induce large numbers of small projects.

This is surprisingly inconvenient for WordPress plugin and theme development.

Be wary of project overindulgence. Starting with Git, It all seems so innocent

Creating projects is simple, easy & fun!But projects seem to proliferate :(

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Which one is better, Git or Subversion?

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1st: There is no one-size-fits-all tool which is “better” than every other tool.

2d: Git and Subversion are going to be around a long, long time. The closer you are to developers, the more likely you’re going to learn both anyway.

3d: If your main interest is WordPress development, learn Subversion now. Yesterday. Seriously. Then learn Git.

4th: If you’re riding Rails, you probably already know you need to learn Git. Mandatory.

My opinion: if you work with information, you won’t escape learning version control. It’s inevitable.

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Bruce Lee’s Kung Fu guide to learning version control

1. Novice stage: At first, version control is just “version control.” Get a repository, make some changes, save the changes.

2. Practitioner stage: Committing, pushing, rebasing, rolling back, branching, merging, moving, renaming... the pros and cons of a dozen systems to explore.

3. Mastery stage: Version control is just version control. It’s easy and fun!

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Image courtesy Wikipedia

Don’t wait. Start learning version control now.

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With a little help from...

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‘Cause version control is a little like voodoo, doncha know.

portable motivation.

so cool.

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Find this presentation on Slideshare

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