Giter8 is a command line tool to generate files and directories from templates published on github. It's implemented in Scala and runs through the Simple Build Tool launcher, but it can produce output for any purpose.
You can install giter8 and other Scala command line tools with
Conscript. This will setup Conscript in ~/bin/cs:
curl https://raw.github.com/n8han/conscript/master/setup.sh | sh
(See Conscript's readme for a non-unixy option.) Once cs is
on your path, you can install (or upgrade) giter8 with this command:
cs n8han/giter8
To make sure everything is working, try running g8 with no
parameters. This should download giter8 and its dependencies, then print
a usage message.
When it's time to upgrade to a new version of giter8, just run the
same cs command again.
Giter8 is also installable with the OS X package manager Homebrew:
$ brew update && brew install giter8
Template repositories must reside on github and be named with the
suffix .g8. We're keeping a list of templates on the wiki.
To apply a template, for example, softprops/unfiltered.g8:
$ g8 softprops/unfiltered.g8
The .g8 suffix is assumed:
$ g8 softprops/unfiltered
Either way, giter8 resolves this to the softprops/unfiltered.g8
repository and queries github for the project's template
parameters. You'll be prompted for each parameter, with its default
value in square brackets:
name [My Web Project]:
Enter your own value or press enter to accept the default. After all values have been supplied, giter8 fetches the templates, applies the parameters, and writes them to your filesystem.
If the template has a name parameter, it will be used to create base
directory in the current directory (typical for a new project).
Otherwise, giter8 will output its files and directories into
the current directory, skipping over any files that already exist.
Once you become familiar with a template's parameters, you can enter them on the command line and skip the interaction:
$ g8 softprops/unfiltered.g8 --name=my-new-website
Any unsupplied parameters are assigned their default values.
Giter8 accesses GitHub anonymously by default, but for private templates you can authenticate.
$ g8 --auth yourname:yourpass
This stores a github OAuth
token in ~/.g8/config which is then used for future g8
invocations. The token can be revoked at any time in your
github settings.
If you wish to use basic authentication instead, you can specify a
github.user and github.password in your global git properties. The
OAuth token is preferred and will be used when both are present.
The g8 runtime looks for templates in the src/main/g8 directory of a
given github project. This structure is used so that it is easy (but
not required) for the template itself to be an sbt project. That way,
an sbt plugin can be employed to locally test templates before pushing
changes to github.
The easy way to start a new template project is with a giter8 template made expressly for that purpose:
$ g8 n8han/giter8
This will create an sbt project with stub template sources nested
under src/main/g8. The file default.properties defines template
fields and their default values using the Java properties file format.
Properties can be simple keys and values that replace them, but ls properties tell giter8 to query the ls.implicit.ly web API. Instead of supplying a particular version (and having to update the template with every release), specify a library and giter8 will set the value to the latest version according to ls.
The property value format is ls(library, user, repo). The second two
parameters are optional, but it is a good idea to specify the github
at least the user or organization that is bound to the library, in
case someone else ever publishing a library module with the same name.
The n8han/giter8.g8 template itself uses this feature to refer to the latest version of the giter8 sbt plugin.
name = My Template Project
description = Creates a giter8 project template.
giter8_version = ls(giter8-plugin, n8han)
StringTemplate, wrapped by Scalasti, is the engine
that applies giter8 templates, so template fields in source files are
bracketed with the $ character. For example, a "classname" field
might be referenced in the source as:
class $classname$ {
The name field, if defined, is treated specially by giter8. It is
assumed to be the name of a project being created, so the g8 runtime
creates a directory based off that name (with spaces and capitals
replaced) that will contain the template output. If no name field is
specified in the template, g8's output goes to the user's current
working directory. In both cases, directories nested under the
template's source directory are reproduced in its output. File and
directory names also participate in template expansion, e.g.
src/main/g8/src/main/scala/$classname$.scala
The package field, if defined, is assumed to be the package name
of the user's source. A directory named $package$ expands out to
package directory structure. For example, net.databinder becomes
net/databinder.
The verbatim field, if defined, is assumed to be the space delimited
list of file patterns such as *.html *.js. Files matching verbatim
pattern are excluded from string template processing.
Giter8 has built-in support for formatting template fields. Formatting options
can be added when referencing fields. For example, the name field can be
formatted in upper camel case with:
$name;format="Camel"$
The formatting options are:
upper | uppercase : all uppercase letters
lower | lowercase : all lowercase letters
cap | capitalize : uppercase first letter
decap | decapitalize : lowercase first letter
start | start-case : uppercase the first letter of each word
word | word-only : remove all non-word letters (only a-zA-Z0-9_)
Camel | upper-camel : upper camel case (start-case, word-only)
camel | lower-camel : lower camel case (start-case, word-only, decapitalize)
hyphen | hyphenate : replace spaces with hyphens
norm | normalize : all lowercase with hyphens (lowercase, hyphenate)
snake | snake-case : replace spaces with underscores
packaged | package-dir : replace dots with slashes (net.databinder -> net/databinder)
random | generate-random : appends random characters to the given string
A name field with a value of My Project could be rendered in several ways:
$name$ -> "My Project"
$name;format="camel"$ -> "myProject"
$name;format="Camel"$ -> "MyProject"
$name;format="normalize"$ -> "my-project"
$name;format="lower,hyphen"$ -> "my-project"
Note that multiple format options can be specified (comma-separated) which will be applied in the order given.
For file and directory names a format option can be specified after a double
underscore. For example, a directory named $organization__packaged$ will
change org.somewhere to org/somewhere like the built-in support for
package. A file named $name__Camel$.scala and the name awesome project
will create the file AwesomeProject.scala.
Giter8 supplies an sbt plugin for testing templates before pushing
them to a github branch. If you used the n8han/giter8.g8 template
recommended above, it should already be configured. If you need to
upgrade an existing template project to the current plugin, you can
add it as a source dependency in project/project/plugins.scala:
import sbt._
object PluginDef extends Build {
lazy val root = Project("plugins", file(".")) dependsOn( g8plugin )
lazy val g8plugin =
ProjectRef(uri("git://github.com/n8han/giter8#0.4.4"), "giter8-plugin")
}And settings must be applied in a build.sbt file in the project base:
seq(giter8Settings :_*)
When you enter sbt's interactive mode in the base directory of a
template project that is configured to use this plugin, the action
g8-test will apply the template in the default output directory
(under target/sbt-test) and run the scripted test for that project
in a forked process. You can supply the test scripted as
src/test/g8/test, otherwise >test is used. This is a good sanity
check for templates that are supposed to produce sbt projects.
But what if your template is not for an sbt project?
src/main/g8/default.properties
src/main/g8/TodaysMenu.html
You can still use sbt's interactive mode to test the template. The
lower level g8 action will apply default field values
to the template and write it to the same target/g8 directory.
As soon as you push your template to github (remember to name the
project with a .g8 extension) you can test it with the actual g8
runtime. When you're ready, add your template project to the
the wiki so other giter8 users can find it.