Generate new projects from Leiningen or Boot templates, or clj-template
projects, using just the clojure
command-line installation of Clojure!
For support, help, general questions, use the #deps-new channel on the Clojurians Slack.
Note: these instructions assume you are using the Clojure CLI version 1.10.3.933 or later! See Clojure Tools Releases for details about the functionality in recent CLI releases. Projects generated by
clj-new
also assume at least version 1.10.3.933!
If you want to create basic application or library projects, or you want to develop your own templates, I recommend looking at
deps-new which is a simpler, newer project, based around tools.build
.
The easiest way to use clj-new
is by installing it as a "tool" instead of updating your deps.edn
file and then invoke it using the following commands:
# one-off to install clj-new as a tool:
clojure -Ttools install-latest :lib com.github.seancorfield/clj-new :as clj-new
Note: older versions of this documentation -- and some public templates' documentation -- showed installation
:as new
but that is the alias recommended fordeps-new
so this project now recommends:as clj-new
instead, to avoid conflicts.
# commands to create new projects:
# create a new app:
clojure -Tclj-new app :name myname/myapp
# create a new library:
clojure -Tclj-new lib :name myname/mylib
# create a new template:
clojure -Tclj-new template :name myname/mytemplate
# create a new project from a public template:
clojure -Tclj-new create :template electron-app :name myname/myelectron-app
Note: if you have created a new project from a public template, follow the instructions for that template on how to use and run the project -- all templates are different! The built-in
app
,lib
, andtemplate
projects are described briefly below but also have their own README files in their newly created projects.
You can get help about the functions available in clj-new
:
clojure -A:deps -Tclj-new help/doc
Note: if you are on Windows, read Quoting keys and values in the official Deps and CLI Reference documentation to understand how the above commands need to look on Powershell. Or take a look at the Babashka CLI library support.
If you don't want to install clj-new
as a "tool", you can add an alias to your ~/.clojure/deps.edn
file (or ~/.config/clojure/deps.edn
file) like this:
;; add this inside your :aliases map:
:clj-new {:extra-deps {com.github.seancorfield/clj-new
{:mvn/version "1.3.415"}}
:exec-fn clj-new/create
:exec-args {:template "app"}}
A minimal, complete deps.edn
file with just this :clj-new
alias would look like this:
{:aliases
{:clj-new {:extra-deps {com.github.seancorfield/clj-new {:mvn/version "1.3.415"}}
:exec-fn clj-new/create
:exec-args {:template "app"}}}}
Now you can create a basic application:
clojure -X:clj-new :name myname/myapp
cd myapp
clojure -M -m myname.myapp
Run the tests:
clojure -T:build test
or you can create a basic library:
clojure -X:clj-new :template lib :name myname/mylib
cd mylib
Run the tests:
clojure -T:build test
If you think you are going to be creating more libraries than applications, you could specify :template "lib"
in the :exec-args
hash map, to specify the default. Or you could provide different aliases, such as:
;; add these into your :aliases map:
:new-app {:extra-deps {com.github.seancorfield/clj-new
{:mvn/version "1.3.415"}}
:exec-fn clj-new/create
:exec-args {:template "app"}}
:new-lib {:extra-deps {com.github.seancorfield/clj-new
{:mvn/version "1.3.415"}}
:exec-fn clj-new/create
:exec-args {:template "lib"}}}
Now you can use those as follows:
clojure -X:new-app :name myname/myapp
clojure -X:new-lib :name myname/mylib
The babashka CLI library allows you to call
an -X
(exec) function in a more Unixy way, without writing EDN on the command
line. If you are dealing with quoting issues in your shell, this could be a
viable alternative:
:clj-new {:deps {org.babashka/cli {:mvn/version "0.2.14"}
com.github.seancorfield/clj-new {:mvn/version "1.3.415"}}
:exec-fn clj-new/create
:exec-args {:template "app"
:env {:group io.github.myuser}}
:main-opts ["-m" "babashka.cli.exec"]}
Note that we no longer need quotes to call the same exec function:
$ clj -M:clj-new --name foo/bar --args 1 2 3 --query
Will create the folder: bar
From the template: app
Passing these arguments: 1 2 3
The following substitutions will be used:
{:date "2022-06-05",
:group io.github.myuser,
:name "bar",
:sanitized "bar",
:year 2022,
:scm-domain "github.com",
:template-nested-dirs "{{nested-dirs}}",
:artifact "bar",
:developer "Borkdude",
:nested-dirs "foo/bar",
:version "0.1.0-SNAPSHOT",
:namespace "foo.bar",
:user "borkdude",
:scm-user "foo",
:raw-name "foo/bar"}
The following :exec-args
can be provided for clj-new/create
:
:name
-- the name of the project (as a symbol or a string); required; must be a qualified project name or a multi-segment dotted project name:template
-- the name of the template to use (as a symbol or a string); required:args
-- an optional vector of strings (or symbols) to pass to the template itself as command-line argument strings:edn-args
-- an optional EDN expression to pass to the template itself as the arguments for the template; takes precedence over:args
; nearly all templates expect a sequence of strings so:args
is going to be the easiest way to pass arguments:env
-- a hash map of additional variable substitutions in templates (see The Generatedpom.xml
File below for a list of "built-in" variables that can be overridden):force
-- iftrue
, will force overwrite the target directory if it exists:help
-- iftrue
, will provide a summary of these options as help:output
-- specify the project directory to create (the default is to use the project name as the directory):query
-- iftrue
, instead of actually looking up the template and generating the project, output an explanation of whatclj-new
will try to do:snapshot
-- iftrue
, look for -SNAPSHOT version of the template (not just a release version):verbose
-- 1, 2, or 3, indicating the level of debugging in increasing detail:version
-- use this specific version of the template, e.g.,'"1.2.3"'
(remember that strings need to be 'quoted' as exec args)
Unlike Leiningen, clj-new
requires that you use either a qualified
name for your project, such as <username>/<project-name>
or
<org-name>/<project-name>
, or a dotted name, such as my.project
.
If you are going to publish a library, it will have a group ID and an artifact ID (e.g.,
com.github.seancorfield/clj-new
) and the group ID should be something unique to you or your
organization -- most people use their GitHub username or their company name (i.e., their domain
name in reverse, e.g., com.stuartsierra/component
). The qualified name you provide to
clj-new
is effectively group/artifact
(but keep reading!). clj-new
uses that to create the main namespace:
src/group/artifact.clj
containing (ns group.artifact ...)
-- this ensures that when someone
uses your library, it's not going to clash with other code because the first portion of the
namespace should be something unique to you or your organization.
If you plan on publishing your library to clojars.org your project
should have a group ID that follows the Clojars Verified Group Names policy.
If you use myname/mylib
as your project name, clj-new
will generate a pom.xml
file
with a group ID of net.clojars.myname
and assume the library source will live at
https://github.com/myname/mylib
(so that clojure -T:build ci
and clojure -T:build deploy
will "do the right thing" by default). The main namespace will be myname.mylib
,
in src/myname/mylib.clj
. See The Generated pom.xml
File
below for more details about group and artifact IDs.
If you use com.github.myname/mylib
as your project name, clj-new
will use com.github.myname
as the group ID and mylib
as the artifact ID but will use myname.mylib
as the primary
namespace, in src/myname/mylib.clj
, rather than src/com/github/myname/mylib.clj
(and com.github.myname.mylib
). You should think about whether myname.mylib
is unique
enough that users of your library will not encounter conflicts with namespaces in other
libraries. clj-new
also understands io.github.myname
, com.gitlab.myname
, and
io.gitlab.myname
in project names.
It's good practice to follow this convention even if you are creating an application, or a library that you don't plan to publish, because it will mean that your code is much less likely to clash with any libraries your code uses.
If you're unsure about how clj-new
will compute the group, artifact, main namespace, and so on,
you can use the :query true
option, and clj-new
will print out what it will do:
$ clojure -Tclj-new lib :query true :name myname/myproj
Will create the folder: myproj
From the template: app
The following substitutions will be used:
{:date "2021-03-02",
:group "net.clojars.myname",
:name "myproj",
:sanitized "myproj",
:year 2021,
:scm-domain "github.com",
:template-nested-dirs "{{nested-dirs}}",
:artifact "myproj",
:developer "Seanc",
:nested-dirs "myname/myproj",
:version "0.1.0-SNAPSHOT",
:namespace "myname.myproj",
:user "seanc",
:scm-user "myname",
:raw-name "myname/myproj"}
# or:
$ clojure -X:clj-new :query true :name myname/myproj
You can use the :env
option to pass in a hash map of substitutions to override any of these.
Note:
lein new myapp
will treatmyapp
as both the group ID and the artifact ID, which is why a lot of older Clojure libs just have an unqualified lib name, likering
-- but really it'sring/ring
and recent versions of the Clojure CLI display a deprecation warning on justring
: see the Deprecated unqualified lib names section near the end of this Inside Clojure post about the-X
option. Leiningen also stuck.core
onto your project name to create the main namespace, which is why a lot of older Clojure libs have asomething.core
namespace: just because Leiningen did that by default. Both default behaviors here are bad because they're likely to lead to conflicts with other libraries.
You can get something close to Leiningen's default behavior by specifying a dotted project
name that ends in .core
, e.g., clojure -Tclj-new lib :name foo.core
. That will create a folder
called foo.core
and the project will have a group ID of net.clojars.foo
and an artifact ID of
foo.core
-- which is similar behavior to running lein new foo.core
but complies with Clojars'
Verified Group Names policy -- with a main namespace of foo.core
in src/foo/core.clj
.
[lein new foo
creates a folder called foo
and the project has a group ID of foo
and an artifact ID of foo
, even though the main namespace will be foo.core
].
Built-in templates are:
app
-- A minimal Hello World! application withdeps.edn
. Can run it viaclojure -M -m
and can test it withclojure -T:build test
.lib
-- A minimal library withdeps.edn
. Can test it withclojure -T:build test
.polylith
-- A minimal Polylith workspace with a minimal application project and a minimal library project (new in 1.1.293).template
-- A minimalclj-new
template.
Third-party templates can be used like this:
clojure -Tclj-new create :template clj-py-r-template :name myname/mylib
This requires that the naming conventions for templates are followed, and one of the following templates exists in the remote repository (Maven, Clojars, etc):
clj-py-r-template/clj-template
clj-py-r-template/lein-template
clj-py-r-template/boot-template
If your template name is a qualified symbol, such as us.technomancy/liquid-cool
, the following templates are searched for:
us.technomancy/clj-template.liquid-cool
us.technomancy/lein-template.liquid-cool
us.technomancy/boot-template.liquid-cool
Leiningen's documentation has a detailed explanation of how template names map to group and artifact IDs. Boot does not yet support qualified template names.
Note: you can currently find third-party templates on Clojars using these searches
<template-name>/clj-template
,<template-name>/lein-template
or<template-name>/boot-template
. The project created from each template is likely to be different -- maybeproject.clj
, maybedeps.edn
, maybe something else -- consult the template's documentation on how to use the newly created project!
As noted above, the project name should be a qualified Clojure symbol, where the first part is typically your GitHub account name or your organization's domain reversed, e.g., com.acme
, and the second part is the "local" name for your project (and is used as the name of the folder in which the project is created), e.g., com.acme/my-cool-project
. This will create a folder called my-cool-project
and the main namespace for the new project will be com.acme.my-cool-project
, so the file will be src/com/acme/my_cool_project.clj
. In the generated pom.xml
file, the group ID will be com.acme
and the artifact ID will be my-cool-project
-- following this pattern means you are already set up for publishing to Clojars (or some other Maven-like repository).
An alternative is to use a multi-segment project name, such as com.acme.another-project
. This will create a folder called com.acme.another-project
(compared to above, which just uses the portion after the /
). The main namespace will be com.acme.another-project
in src/com/acme/another_project.clj
, similar to the qualified project name above. In the generated pom.xml
file, the group ID will be the "stem" of the project name (com.acme
) and the artifact ID will be the full project name (com.acme.another-project
) -- again, you'll be set up for publishing to Clojars etc, but be aware of the difference between how dotted names and qualified names affect the generated project.
As noted above, you can override any of these subsitutions using the :env
option, if you need to.
$ clojure -Tclj-new create :query true :name com.acme.another-project
Will create the folder: com.acme.another-project
From the template: app
The following substitutions will be used:
{:date "2021-03-02",
:group "com.acme",
:name "com.acme.another-project",
:sanitized "com.acme.another_project",
:year 2021,
:scm-domain "github.com",
:template-nested-dirs "{{nested-dirs}}",
:artifact "com.acme.another-project",
:developer "Seanc",
:nested-dirs "com/acme/another_project",
:version "0.1.0-SNAPSHOT",
:namespace "com.acme.another-project",
:user "seanc",
:scm-user "com.acme",
:raw-name "com.acme.another-project"}
You can, of course, modify the generated pom.xml
file to have whatever group and artifact ID you want, if you don't like these defaults.
The generated project is an application. It has a -main
function in the main project
namespace, with a (:gen-class)
class in the ns
form. In addition to being able to
run the project directly (with clojure -M -m myname.myapp
) and run the tests, you can
also build an uberjar for the project with clojure -T:build ci
, which you can then
run with java -jar target/myapp-0.1.0-SNAPSHOT.jar
.
The generated project is a library. It has no -main
function. In addition to
being able to run the tests, you can also build a jar file for deployment
with clojure -T:build ci
. You will probably need to adjust some of the information
inside the generated pom.xml
file before deploying the jar file.
The generated project includes a pom.xml
file on the assumption that you will be deploying
the library to Clojars or a similar repository. It will be kept in sync with deps.edn
automatically whenever you run clojure -T:build ci
to build the library and it will be added
to the JAR file. If you do not intend to
deploy the library, you can delete the pom.xml
file.
If you are going to deploy the library, you'll probably want to review and adjust some
of the fields in the pom.xml
(developer information, group/artifact, version, SCM,
licensing etc) -- although the defaults should mostly be suitable out of the box.
Once you've updated the pom.xml
file, you can install it locally with
clojure -T:build install
or deploy it to Clojars with
clojure -T:build deploy
. For that you need these environment variables set:
CLOJARS_USERNAME
-- your Clojars usernameCLOJARS_PASSWORD
-- your Clojars password
Whilst you can create a new Polylith workspace with the poly create workspace
command,
that produces a completely empty workspace skeleton. This clj-new
template produces
a workspace that has some example code in it:
bases
-- contains a command-line API (cli
)components
-- contains a simple component (greeter
interface and implementation)projects
-- contains a simple application, based oncli
andgreeter
, and a simple library, based ongreeter
The generated README shows how you can run tests, build an uberjar, and build a library JAR.
See the Polylith documentation for more details.
The generated project is a very minimal clj-template
. It has no -main
function and has no tests. You can however build a jar file for deployment
with clojure -T:build ci
. You will probably need to adjust some of the information
inside the generated pom.xml
file before deploying the jar file.
Note: when you create a template project called myname/mytemplate, you will get a folder called
mytemplate
and thepom.xml
file will specify the group/artifact asnet.clojars.myname/clj-template.mytemplate
which is a convention supported byclj-new
.
As with the lib
template, this template includes a pom.xml
to make it easier
to deploy the template as a library. Once you have reviewed and possibly updated
the pom.xml
file, you can install it locally or deploy it to Clojars, via the
appropriate aliases.
Each of the built-in templates produces a project that contains a pom.xml
file, which is used to build the uberjar (app
) or jar file (lib
and template
),
as well as guide the deployment of the latter two. If you don't plan to deploy the
library or template, or you just don't want a pom.xml
lying around for your application,
you can delete it.
The goal is such that if you used an appropriate myname/myapp
style name for the
project that you asked clj-new
to create, then most of the fields in the
pom.xml
file should be usable as-is.
You can override the default value of several fields in the pom.xml
file
using the :env
exec-arg to clj-new/create
as a hash map:
:group
-- defaults to themyname
portion ofmyname/myapp
(but see below),:artifact
-- defaults to themyapp
portion ofmyname/myapp
,:version
-- defaults to"0.1.0-SNAPSHOT"
,:description
-- defaults to"FIXME: my new ..."
(application
,library
, ortemplate
),:developer
-- defaults to a capitalized version of your computer's logged in username.:scm-domain
-- defaults github.com
(but see below); used in all the SCM links in the generated projects:https://{{scm-domain}}/{{scm-user}}/{{artifact}}
:scm-user
-- defaults to (part of) the group name (but see below); used in all the SCM links in the generated projects:https://{{scm-domain}}/{{scm-user}}/{{artifact}}
Note:
clj-new
tries to conform to the Clojars Verified Group Names policy -- which is similar to Maven Central's policy about group IDs -- by setting the default for:group
to be something that seems to be a reverse domain name. If you usemyname/myapp
for your project name, the default for:group
will benet.clojars.myname
,:artifact
will bemyapp
,:scm-domain
will begithub.aaakk.us.kg
, and:scm-user
will bemyname
. If you usecom.github.myname/myapp
for your project name, the default for:group
will becom.github.myname
,:artifact
will bemyapp
,:scm-domain
will begithub.aaakk.us.kg
, and:scm-user
will bemyname
.clj-new
also recognizesio.github
,com.gitlab
, andio.gitlab
prefixes. The latter two will cause:scm-domain
to default togitlab.com
. If your project name seems to have a group name that could be a reverse domain name, then it will be accepted as is, e.g.,com.acme/myapp
would produce:group "com.acme", :artifact "myapp", :scm-domain "github.com", :scm-user "com.acme"
.
The :description
field is also used in the generated project's README.md
file.
Example:
clojure -Tclj-new app :name myname/myapp :env '{:group "com.acme" :artifact my-cool-app :version "1.2.3" :scm-user myusername}'
This creates the same project structure as in the earlier myname/myapp
example except that the generated pom.xml
file will contain:
<groupId>com.acme</groupId>
<artifactId>my-cool-app</artifactId>
<version>1.2.3</version>
<name>myname/myapp</name>
<description>FIXME: my new application.</description>
<url>https://github.com/myusername/my-cool-app</url>
...
<scm>
<url>https://github.com/myusername/my-cool-app</url>
<connection>scm:git:git://github.com/myusername/my-cool-app.git</connection>
<developerConnection>scm:git:ssh://[email protected]/myusername/my-cool-app.git</developerConnection>
<tag>v1.2.3</tag>
</scm>
The generated projects (from the built-in app
, lib
, and template
templates) all
contain a LICENSE
file which is the Eclipse Public License (version 1.0) and that
is also mentioned in the generated README.md
files. This is a tradition that started
with Leiningen's lein new
and carried over into boot new
and now clj-new
. The
idea is that it's better to ensure any open source projects created have a valid
license of some sort, as a starting point, and historically most Clojure projects use
the EPLv1.0 because Clojure itself and the Contrib libraries have all used this license
for a long time.
You are not required to open source your generated project! Just because the projects
are generated with an open source LICENSE
file and have a License section in their
README.md
files does not mean you need to keep that license in place.
You are not required to use EPLv1.0 for your project! If you prefer a different license,
use it! Replace the LICENSE
file and update the README.md
file to reflect your personal
preference in licensing (I have tended to use the Apache License 2.0 in most of my open source projects, prior to working with Clojure,
but see Prefer the MIT License for an alternative
viewpoint from the folks who wrote XTDB).
Note: if you incorporate any source code from other people's open source projects, be aware of the legal implications and that you must respect whatever license they have used for that code (which may require you to release your enhancements under the same license and will, most likely, require you to include their copyright notices, etc). Do not copy other people's code without attribution!
The general form of the command is:
clojure -Tclj-new create :template template-name :name project-name :args '[arg1 arg2 arg3 ...]'
As noted above, project-name
should be a qualified symbol, such as mygithubusername/my-new-project
, or a multi-segment symbol, such as my.cool.project
. Some templates will not work with the former but it is recommended you try that format first.
If template-name
is not one of the built-in ones (or is not already on the classpath), clj-new
will attempt to find it on Clojars or Maven Central (or any other :mvn/repos
you have configured) in the following manner:
- If
template-name
is a qualified name,some.group/example
, look for:some.group/clj-template.example
, thensome.group/boot-template.example
, thensome.group/lein-template.example
,
- Else, for an unqualified name, look for:
template-name/clj-template
, thentemplate-name/boot-template
, thentemplate-name/lein-template
.
Currently, Boot and Leiningen only support the second form, with an
unqualified template-name
(Leiningen is adding support for the qualified form).
Historically, clj-new
also only
supported the unqualified template-name
but as of 1.1.264 the
qualified name is also supported so that templates can have group
names that follow the Clojars Verified Group Names policy
and artifact names that start with clj-template.
.
clj-new
should be able to run any existing Leiningen or Boot templates (if you find one that doesn't work, please tell me about it!) -- with the caveat that some Leiningen and Boot templates do not accept a qualified project name and so you must use a dotted project name instead.
clj-new
will generate a new project folder based on the project-name
containing files generated from the specified template-name
. It does that by requiring clj.new.<template-name>
(or boot.new.<template-name>
or leiningen.new.<template-name>
) and invoking the <template-name>
function inside that namespace, passing in <project-name>
and those arguments from the command line.
Alternatively, template-name
can be a :git/url
and :sha
like this:
clojure -Tclj-new create :template '"https://github.com/somename/someapp@c1fc0cdf5a21565676003dbc597e380467394a89"' \
:name project-name :args '[arg1 arg2 arg3 ...]'
In this case, clj.new.someapp
must exist in the template and clj.new.someapp/someapp
will be invoked to generate the template. A GitHub repository may include multiple templates, so you can also use this form:
clojure -Tclj-new create :template '"https://github.com/somename/somerepo/someapp@c1fc0cdf5a21565676003dbc597e380467394a89"' \
:name project-name :args '[arg1 arg2 arg3 ...]'
somename/somerepo
here contains templates in subdirectories, including someapp
. Again, clj.new.someapp
must exist in the template in that subdirectory and clj.new.someapp/someapp
will be invoked to generate the template.
Or, template-name
can be a :local/root
and template name like this:
clojure -Tclj-new create :template '"/path/to/clj-template::new-app"' \
:name project-name :args '[arg1 arg2 arg3 ...]'
In this case, clj.new.new-app
must exist in the template and clj.new.new-app/new-app
will be invoked to generate the template.
Note: since the
:git/url
and:local/root
forms of:template
cannot be provided as Clojure symbols, they must be provided as Clojure strings, with"..."
, and those must be quoted for the shell correctly, with'...'
around the string.
If the folder for project-name
already exists, clj-new
will not overwrite it unless you specify the :force
option.
Here are some examples, generating projects from existing templates:
clojure -Tclj-new create :template luminus :name yourname/example.webapp :output mywebapp :args '[+http-kit +h2 +reagent +auth]'
This creates a folder called mywebapp
with a Luminus web application that will use http-kit
, the H2 database, the Reagent ClojureScript library, and the Buddy library for authentication. The -main
function is in yourname.example.webapp.core
, which is in the mywebapp/src/clj/yourname/example/webapp/core.clj
file. Note that the Luminus template produces a Leiningen-based project, not a CLI/deps.edn
one, but you can also tell it to produce a Boot-based project (with +boot
).
clojure -Tclj-new create :template re-frame :name yourname.spa :output front-end :args '[+garden "+10x" +routes]'
This creates a folder called front-end
with a ClojureScript Single Page Application that uses re-frame for state management, Garden for CSS, re-frame-10x for debugging, and bidi + pushy for routing. The entry point is in the yourname.spa.core
namespace which is in the front-end/src/cljs/yourname/spa/core.cljs
file. The re-frame
template produces a shadow-cljs project, not a CLI/deps.edn
one. Note that +10x
needs to be quoted, because it is not a valid EDN symbol.
Note: the
re-frame
template (a Leiningen template) does not support qualified project names so you have to use a dotted name instead --yourname/spa
would produce an invalidshadow-cljs.edn
file in the project.
clojure -Tclj-new create :template electron-app :name yourname/example
This creates a folder called example
with a skeleton Electron application, using Figwheel and Reagent. The entry point is in the example.main.core
namespace which is in the example/src/main/example/main/core.cljs
file. This Electron template produces a CLI/deps.edn
-based project.
In general, consult the documentation for the template you used for how the newly created
project works. Generally, Leiningen templates produce Leiningen projects (with a
project.clj
file), Boot templates produce Boot projects, and a clj-template
will
produce a CLI / deps.edn
project. Some templates support multiple build tools. Some
projects don't support any of these and use some other build tool.
clj
templates are very similar to Leiningen and Boot templates but have an artifact name based on clj-template
instead of lein-template
or boot-template
and use clj
instead of leiningen
or boot
in all the namespace names. In particular the clj.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 (or boot.new.templates
when writing a Boot Template). The built-in templates are clj
templates, that produce clj
projects with deps.edn
files.
If your template project name is myname/foo-bar
, then you should have clj.new.foo-bar
as the main namespace and it should contain a foo-bar
function that will render the template:
;; src/clj/new/foo_bar.clj:
(ns clj.new.foo-bar ,,,)
(defn foo-bar
"Generate a cool new foo bar project!"
[name & args]
,,,)
When you publish it to Clojars, it should have an appropriate
(reverse domain name) group ID and the artifact ID should match
the template name preceded by clj-template.
:
net.clojars.myname/clj-template.foo-bar
. If you expect people
to depend on the template via GitHub, you should also name the
repo foo-bar
so that https://github.com/<username>/foo-bar
is the :git/url
people will use.
A minimal example, using the default bare bones template:
$ clojure -Tclj-new create :template template :name myname/mytemplate
Generating a project called mytemplate that is a 'clj-new' template
You will now have a folder called mytemplate
that is a very minimal template.
To create a new project based on that template, you need to have it on the classpath (just as if it were a library) and you also need clj-new
on the classpath since you are using it to generate a project from that template:
$ clojure -Sdeps '{:deps {myname/mytemplate {:local/root "mytemplate"}}}' -Tclj-new create :template mytemplate :name myname/myproject
Generating fresh 'clj new' mytemplate project.
$ tree myproject
myproject
|____deps.edn
|____src
| |____myname
| | |____myproject
| | | |____foo.clj
This example uses a local template project structure, which is probably a good idea when you are developing your template, because the only real way to test a template is by trying to use it to generate a new project.
Once you have it working, you can publish it to GitHub or Clojars just like a regular library.
Previous sections have revealed that it is possible to pass arguments to templates. For example:
clojure -Tclj-new create :template custom-template :name project-name \
:args '[arg1 arg2 arg3]'
These arguments are accessible in the custom-template
function as a second argument.
(ns clj.new.custom-template ,,,)
(defn custom-template
[name & args]
(println name " has the following arguments: " args))
Nearly all templates will expect these to be strings but you can use symbols and clj-new
will coerce them to strings for you:
clojure -Tclj-new create :template custom-template :name project-name \
:args '["arg1" "arg2" "arg3"]'
# can usually be written as:
clojure -Tclj-new create :template custom-template :name project-name \
:args '[arg1 arg2 arg3]'
# unless the arguments cannot be represented as Clojure symbols
Note: conversion of
:args
(and:output
) from symbols to strings was added inclj-new
1.1.297.
Since you can depend on clj-new
as a library, you can invoke clj-new/create
programmatically,
such as in a build/test pipeline. By default, clj-new/create
calls shutdown-agents
when it
completes, which is reasonable for a "tool" but is not conducive to programmatic use. An otherwise
undocumented dynamic Var exists which lets you override this behavior:
(require 'clj-new)
(binding [clj-new.helpers/*shutdown* nil]
(clj-new/create {:template "app" :name 'example/four}))
This will suppress the call to shutdown-agents
.
Note: the
clj-new.helpers
namespace is undocumented and contains implementation details that are subject to change. Only this*shutdown*
Var and behavior should be relied on.
Whereas clj templates will generate an entire new project in a new directory, clj generators are intended to add / modify code in an existing project.
You can either say clojure -Tclj-new generate ...
or add an alias for it:
;; add this inside your :aliases map:
:generate {:extra-deps {com.github.seancorfield/clj-new
{:mvn/version "1.3.415"}}
:exec-fn clj-new/generate}}
Given the alias above, you can say clojure -X:generate
to run one or more generators, based on a :generate
vector argument that you provide. Each generator in the vector is a string -- either "type"
or "type=name"
. The type
specifies the type of generator to use. The name
is the main argument that is passed to the generator.
A clj generator can be part of a project or a template. A generator foo
, has a clj.generate.foo/generate
function that accepts at least two arguments, prefix
and the name
specified as the main argument. prefix
specifies the directory in which to perform the code generation and defaults to src
(it cannot currently be overridden). In addition, any additional arguments 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, and file extension, supplied via an :args
vector of strings. Those default to nil
and "clj"
respectively.
# Inside project folder, relying on the clj-new dependency.
clojure -Tclj-new generate :generate '["file=foo.bar"]' :args '["(ns foo.bar)" "clj"]'
The ns
generator creates a clojure namespace by using the file
generator and providing a few defaults.
clojure -Tclj-new generate :generate '["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.
clojure -Tclj-new generate :generate '["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"
.
clojure -Tclj-new generate :generate '["edn=foo.bar"]' :args '["(ns foo.bar)"]'
You can provide as many generators as you want in the :generate
vector, but if you provide an :args
vector then those arguments will be passed into each of the generator functions, so you may still need to run multiple clojure -Tclj-new generate
commands.
The exec-args available for the generate
function are:
:generate
-- a (non-empty) vector of generator strings to use:args
-- an optional vector of string to pass to the generator itself as command-line arguments:edn-args
-- an optional EDN expression to pass to the generator itself as the arguments for the generator; takes precedence over:args
; nearly all generators expect a sequence of strings so:args
is going to be the easiest way to pass arguments:force
-- iftrue
, will force overwrite the target directory/file if it exists:help
-- iftrue
, will provide a summary of these options as help:prefix
-- specify the project directory in which to run the generator (the default issrc
but:prefix '"."'
will allow a generator to modify files in the root of your project):snapshot
-- iftrue
, look for -SNAPSHOT version of the template (not just a release version):template
-- load this template (using the same rules as forclj-new/create
above) and then run the specified generator:version
-- use this specific version of the template
An emacs package is available which provides a Magit-style interface to clj-new
and deps-new
. It includes some community templates and welcomes for recommendations for more.
This project follows the version scheme MAJOR.MINOR.COMMITS where MAJOR and MINOR provide some relative indication of the size of the change, but do not follow semantic versioning. In general, all changes endeavor to be non-breaking (by moving to new names rather than by breaking existing names). COMMITS is an ever-increasing counter of commits since the beginning of this repository.
Latest stable release: 1.3.415
- Improve the built-in template
template
so that it can be used to seed a newclj
project.
Copyright © 2016-2021 Sean Corfield and the Leiningen Team for much of the code -- thank you!
Distributed under the Eclipse Public License version 1.0.