boot-new

A Boot task that generates projects from Leiningen templates or Boot templates.

Getting Started

Create a basic application:

boot -d boot/new new -t app -n myapp
cd myapp
boot run

Built-in templates are:

• app -- A minimal Hello World! application. Comes with build, run, test tasks. build creates a runnable "uberjar" in the target folder.
• default -- A minimal library. Comes with build, test tasks. build installs a JAR of the project into your local Maven cache so you can use boot watch build while you're developing to have the latest version always available to other projects.
• task -- An example set of Boot tasks. Provides *-pass-thru, *-post, *-pre, *-simple task examples for you to build on, as well as build, test tasks. build works as for default above.
• template -- A minimal Boot template. Provides build, new, test tasks. build works as for default above. new will create a new project based on the template itself.

General Usage

You can specify a template and a project name:

boot -d boot/new new -t template-name -n project-name

boot-new will look for template-name/boot-template (on Clojars and Maven Central). If it doesn't find a Boot Template (see below), it will look for template-name/lein-template instead. boot-new should be able to run any existing Leiningen template (if you find one that doesn't work, please tell me about it!). boot-new will then generate a new project folder called project-name containing files generated from the specified template-name.

If the folder project-name already exists, boot-new will not overwrite it unless you specify the -f / --force option. You can override the folder name used with the -o / --to-dir option. By default, boot-new will look for the most recent stable release of the specified template. You can tell it to search for snapshots with the -S / --snapshot option, and you can specify a particular version to use with the -V / --template-version option. In general, the long-form option follows the naming used by Leiningen's new task for familiarity.

You can pass arguments through to the underlying template with the -a / --args option (Leiningen uses -- to separate template arguments from other options but Boot already parses options a little differently).

For a full list of options, ask new for help:

boot -d boot/new new -h

The intent is that all of the basic options from Leiningen's new task are supported, along with Boot-specific versions of the built-in templates (app, default, task -- instead of Leiningen's plugin, and template).

Boot Templates

Boot templates are very similar to Leiningen templates but have an artifact name based on boot-template instead of lein-template and uses boot instead of leiningen in all the namespace names. In particular the boot.new.templates namespace provides functions such as renderer and ->files that are the equivalent of the ones found in leiningen.new.templates when writing a Leiningen Template. The built-in templates are Boot templates, that produce Boot projects.

To develop a new template, run boot -d boot/new new -t template -n my-template. This will generate a project whose build.boot has (def project 'my-template/boot-template), with version 0.1.0-SNAPSHOT. To test it, you will need to build and install it locally (the generated build.boot contains a build task for this purpose) and then use it to create a project, using either --snapshot or --template-version so boot-new will know which version to use. By default, it looks for the most recent non-SNAPSHOT release on clojars.org.

Arguments

Previous sections have revealed that it is possible to pass arguments to templates. For multiple arguments, use one -a for each argument. For example:

# Inside custom-template folder, relying on that template's boot new task.
boot new -t custom-template -n project-name -a arg1 -a arg2 -a arg3

These arguments are accessible in the custom-template function as a second argument.

(defn custom-template
  [name & args]
  (println name " has the following arguments: " args))

Boot Generators

Whereas Boot templates will generate an entire new project in a new directory, Boot generators are intended to add / modify code in an existing project. boot-new will run a generator with the -g type or -g type=name options. The type specifies the type of generator to use. The name is the main argument that is passed to the generator.

A Boot generator can be part of a project or a template. A generator foo, has a boot.generate.foo/generate function that accepts at least two arguments, prefix and the name specified in the -g / --generate option (which will be nil if no name was specified -- the generator should validate that). prefix specifies the directory in which to perform the code generation and defaults to src. It can be overridden with the -p / --prefix option, but a generator is also free to simply ignore it anyway. In addition, any arguments specified by the -a / --args option are passed as additional arguments to the generator.

There are currently a few built-in generators:

• file
• ns
• def
• defn
• edn

The file generator creates files relative to the prefix. It optionally accepts a body, file extension, and append? argument.

boot -d boot/new new -g file=foo.bar -a "(ns foo.bar)" -a "clj"

The ns generator creates a clojure namespace by using the file generator and providing a few defaults.

boot -d boot/new new -g ns=foo.bar

This will generate src/foo/bar.clj containing (ns foo.bar) (and a placeholder docstring). It will not replace an existing file unless you specify -f / --force (so ns generators are safe-by-default.

boot -d boot/new new -g defn=foo.bar/my-func

If src/foo/bar.clj does not exist, it will be generated as a namespace first (using the ns generator above), then a definition for my-func will be appended to that file (with a placeholder docstring and a dummy argument vector of [args]). The generator does not check whether that defn already exists so it always appends a new defn.

Both the def and defn generators create files using the ns generator above.

The edn generator uses the file generator internally, with a default extension of "edn".

boot -d boot/new new -g edn=foo.bar -a "(ns foo.bar)"

Roadmap

• Improve the built-in template template so that it can be used to seed a new Boot project.

License

Copyright © 2016-2018 Sean Corfield and the Leiningen Team for much of the code -- thank you!

Distributed under the Eclipse Public License version 1.0.