leiningen/doc/TEMPLATES.md

Writing Templates

Suppose you've written a fabulously popular library, used the world over by adoring fans. For the purposes of this document, let's say this library is called "liquid-cool". If using liquid-cool takes a bit of setup, or if you'd just like to give your users a little guidance on how one might best create a new project which uses liquid-cool, you might want to provide a template for it (just like how lein already provides built-in templates for "app", "plugin", and so on).

Let's assume your library's project dir is ~/dev/liquid-cool. Create a template for it like so:

cd ~/dev
lein new template liquid-cool --to-dir liquid-cool-template

Note that you'll now have a new and separate project named "liquid-cool-template". It will have a group-id of "liquid-cool", and an artifact-id of "lein-template".

All lein templates have an artifact-id of "lein-template", and are differentiated by their group-id, which always should match the project for which they provide a template.

Structure

The files that your template will provide to users are in src/leiningen/new/liquid_cool. lein-newnew starts you off with just one, named "foo.clj". You can see it referenced in src/leiningen/new/liquid_cool.clj, right underneath the ->files data line.

You can delete foo.clj if you like (and it's corresponding line in liquid_cool.clj), and start populating that src/leiningen/new/liquid_cool directory with the files you wish to be part of your template. For everything you add, make sure the liquid_cool.clj file receives corresponding entries in that ->files call. For examples to follow, have a look inside the *.clj files for the built-in templates.

While developing a template, if you're in the template project lein-newnew will pick it up and you'll be able to test it. However, if you want to use it on your system without putting it on clojars, just lein install your template.

Distributing your template

Templates are just maven artifacts. Particularly, they need only be on the classpath when lein new is called. So, as a side-effect, you can just put your templates in a jar and toss them on clojars and have people install them like normal Leiningen plugins.

In Leiningen 2.x, templates get dynamically fetched if they're not found. So for instance lein new heroku myproject will find the latest version of the heroku/lein-template project from Clojars and use that.

Users of Leiningen 1.x (1.6.2 or later) can also use the template if they install the lein-newnew plugin:

$ lein plugin install lein-newnew 0.3.6
$ lein new foo
$ lein new plugin lein-foo