Broccoli
A fast, reliable asset pipeline, supporting constant-time rebuilds and compact
build definitions. Comparable to the Rails asset pipeline in scope, though it
runs on Node and is backend-agnostic. For background and architecture, see the
introductory blog post.
For the command line interface, see
broccoli-cli.
This is 0.x beta software.
Windows support is still spotty. Our biggest pain point is unreliable file
deletion (see rimraf#72).
Installation
npm install --save-dev broccoli
npm install --global broccoli-cli
Brocfile.js
A Brocfile.js
file in the project root contains the build specification. It
should export a tree.
A tree can be any string representing a directory path, like 'app'
or
'src'
. Or a tree can be an object conforming to the Plugin API
Specification. A Brocfile.js
will usually
directly work with only directory paths, and then use the plugins in the
Plugins section to generate transformed trees.
The following simple Brocfile.js
would export the app/
subdirectory as a
tree:
module.exports = 'app'
With that Brocfile, the build result would equal the contents of the app
tree in your project folder. For example, say your project contains these
files:
app
├─ main.js
└─ helper.js
Brocfile.js
package.json
…
Running broccoli build the-output
(a command provided by
broccoli-cli) would generate
the following folder within your project folder:
the-output
├─ main.js
└─ helper.js
Using plugins in a Brocfile.js
The following Brocfile.js
exports the app/
subdirectory as appkit/
:
var pickFiles = require('broccoli-static-compiler')
module.exports = pickFiles('app', {
srcDir: '/',
destDir: 'appkit'
})
That example uses the plugin
broccoli-static-compiler
.
In order for the require
call to work, you must first put the plugin in
your devDependencies
and install it, with
npm install --save-dev broccoli-static-compiler
With the above Brocfile.js
and the file tree from the previous example,
running broccoli build the-output
would generate the following folder:
the-output
└─ appkit
├─ main.js
└─ helper.js
A larger example
You can see a full-featured Brocfile.js
in
broccoli-sample-app.
Plugins
You can find plugins on broccoliplugins.com or under the broccoli-plugin keyword on npm.
Running Broccoli, Directly or Through Other Tools
Helpers
Shared code for writing plugins.
Plugin API Specification
Broccoli defines a single plugin API: a tree. A tree object represents a tree
(directory hierarchy) of files that will be regenerated on each build.
By convention, plugins will export a function that takes one or more input
trees, and returns an output tree object. Usually your plugin will be
implemented as a class representing a tree, but it is recommended to make the
new
operator optional
(example).
A tree object must supply two methods that will be called by Broccoli:
tree.read(readTree)
The .read
method must return a path or a promise for a path, containing the
tree contents.
It receives a readTree
function argument from Broccoli. If .read
needs to
read other trees, it must not call otherTree.read
directly. Instead, it must
call readTree(otherTree)
, which returns a promise for the path containing
otherTree
's contents. It must not call readTree
again until the promise
has resolved; that is, it cannot call readTree
on multiple trees in
parallel.
Broccoli will call the .read
method repeatedly to rebuild the tree, but at
most once per rebuild; that is, if a tree is used multiple times in a build
definition, Broccoli will reuse the path returned instead of calling .read
again.
The .read
method is responsible for creating a new temporary directory to
store the tree contents in. Subsequent invocations of .read
should remove
temporary directories created in previous invocations.
tree.cleanup()
For every tree whose .read
method was called one or more times, the
.cleanup
method will be called exactly once. No further .read
calls will
follow .cleanup
. The .cleanup
method should remove all temporary
directories created by .read
.
Debugging
Errors
When it is known which file caused a given error, plugin authors can make errors
easier to track down by setting the .file
property on the generated error.
This .file
property is used by both the console logging, and the server middleware
to display more helpful error messages.
Descriptive Naming
As of 0.11 Broccoli prints a log of any trees that took a significant amount of the total
build time to assist in finding which trees are consuming the largest build times.
To determine the name to be printed Broccoli will first look for a .description
property on the plugin instance then fall back to using the plugin constructor's name.
Security
- Do not run
broccoli serve
on a production server. While this is
theoretically safe, it exposes a needlessly large amount of attack surface
just for serving static assets. Instead, use broccoli build
to precompile
your assets, and serve the static files from a web server of your choice.
Get Help
- IRC:
#broccolijs
on Freenode. Ask your question and stick around for a few
hours. Someone will see your message eventually. - Twitter: mention @jo_liss with your question
- GitHub: Open an issue on a specific plugin repository, or on this
repository for general questions.
License
Broccoli was originally written by Jo Liss and is
licensed under the MIT license.
The Broccoli logo was created by Samantha Penner
(Miric) and is licensed under CC0
1.0.