Managing project builds does not have to be an endless fight with XML. Using Leiningen for Clojure projects allows you to define the project in Clojure as well.

1. L e in in g e n 2
H u m a n e b u ild
m a na g e m e n t fo r
ClojureMadeSimple.co.uk

2. slideshare.net/jr0cket
This slide deck is available to follow along with on slideshare.net

5. of Java build
management

6. ...there was Ant,
Ant begat Ivy,
Ant begat Maven

7. … and there was much XML all around

8. Here end'eth the
lesson..
(except of course this is just the end
of the beginning)

13. Human verses Computer readable build jobs

14. build
management

15. Leiningen
… more fun than Maven
… easy way to kick-start your Clojure
addiction

16. Installing Leiningen
Download the Leiningen 2 install script from
leiningen.org
Move the lein file to an executable location, eg.
~/bin
Make the install script executable and run the
install
chmod u+x ~/bin/lein

17. All the usual tasks,
and then some
lein new Create a new clojure project
lein deps Download all dependencies
lein run Run your application
lein jar Deploy your app as a jar
lein uberjar Deploy your app & clojure
libraries
lein repl Start the interactive shell (repl)
lein jack-in Start repl server and connect (in
Emacs)

18. Fire up the REPL
REPL: read, evaluate, print loop – dynamic
lein repl environment for Clojure and other lisps

19. View function documentation
(doc map)

20. Show function source code
(source map)

21. REPL driven development
Develop functions and data structures on the fly
REPL: read, evaluate, print loop – dynamic environment for Clojure and other lisps

22. Loading code into the REPL
Develop functions and data structures on the fly
REPL: read, evaluate, print loop – dynamic environment for Clojure and other lisps

23. Create a new project
lein new my-project
cd my-project
lein deps
Lein deps will check your project.clj configuration file and
download any libraries (jar files) that are required by the project

24. Anatomy of a new project

25. Create a new project
lein new my-project
cd my-project
lein deps
Lein deps will check your project.clj configuration file and
download any libraries (jar files) that are required by the project

26. Version your project with Git
cd my-project
git init
Create a repo on github & add it to your project
git remote add origin
git@github.com/account/project.git
git push -u origin master
You may want to edit your .git-ignore file also

27. Open project in emacs
cd my-project
emacs project.clj

28. project.clj - project definition
Lein deps will check this project.clj configuration file and
download any libraries (jar files) that are required by the project

29. Dev Dependencies
Add libraries only needed for development
Not packaged when code deployed

30. https://clojars.org/

31. http://search.maven.com

32. Add a REPL server
REPL: read, evaluate, print, loop – dynamic environment for Clojure
and other lisps

33. Add REPL server to all projects
~/.lein/profiles.clj

34. Fire up the REPL in Emacs
M – x
clojure-
jack-in
M – x represents the keyboard combination of the meta key followed by x.
Then the command clojure-jack-in is entered.

35. Define your own Global short-cut
Open your .emacs.d/init.el file and add:
(global-set-key
(kbd "C-c C-j") 'clojure-jack-
in)
In Emacs, start the REPL with
C – c C – j

36. REPL in Emacs

37. Add web based REPL
~/.lein/profiles.clj
REPL: read, evaluate, print, loop – dynamic environment for Clojure
and other lisps

38. Leiningen WebRepl plugin

39. Local Repositories
(just like Maven)

40. Libraries kept in local .m2 folder

41. Nexus / Artefactory repositories
https://github.com/technomancy/leiningen/blob/pr
eview/sample.project.clj

42. Running your
project

43. Create a new project
lein run
Runs the main function, or specify main with -m
option

44. Long running processes
lein trampoline run
-m my-stuff.server 5000

45. Running Tests
lein tests
lein tests my.proj.code

46. Deployment

47. Jars & Uber Jars
lein uberjar

48. Leiningen Plug-ins

49. Running scripts
Copying files
DVCS (git)
Continuous
Integration server
(Jenkins)

51. Leiningen.org
- Tutorials
- Github Repository
- News
- Bug reporting

52. Choose Life...
… choose Clojure

53. Th a n k yo u
LondonClojurians.org
@ r 0c ket
j
ClojureMadeSimple.co.uk
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