grunt-assemble-less
Compile LESS to CSS. Adds experimental features that extend Less.js for maintaining UI components and themes. From Jon Schlinkert, core team member of Less.js.
This project is a fork of the popular grunt-contrib-less by the talented Tyler Kellen. Please use that plugin if you require something stable and dependable.
Getting Started
This plugin requires Grunt ~0.4.2
If you haven't used Grunt before, be sure to check out the Getting Started guide, as it explains how to create a Gruntfile as well as install and use Grunt plugins. Once you're familiar with that process, you may install this plugin with this command:
npm install assemble-less --save-dev
Once the plugin has been installed, it may be enabled inside your Gruntfile with this line of JavaScript:
grunt;
Less task
Run this task with the grunt less
command.
Task targets, files and options may be specified according to the grunt Configuring tasks guide.
Options
lessrc
Type: String
Default: null
A convenience option for externalizing task options into a .lessrc
or .lessrc.yml
file. If this file is specified, options defined therein will be used.
globalVars
Type: Object
Default: undefined
Prepend variables to source files.
modifyVars
Type: Object
Default: undefined
Append variables to source files.
metadata
Type: String|Array
Default: Empty string
Pass metadata as context to Lo-Dash templates embedded in LESS files. The name of the files is used as the first path in the template variables, so if you want to use data from palette.yml
, your templates would look something like: <%= palette.foo %>
.
Data may be formatted in JSON
, YAML
. See this YAML example and this LESS example.
Note that data passed into options.metadata
is merged at the task and target levels. You can turn this off by adding options: {merge: false}
, which then disables merging and allows targets to override any data passed in at the task-level.
imports
Type: Object
(each option accepts a String
or Array
)
Default: null
Prepend @import
statements to src
files using any of the new @import
directives released after Less.js v1.5.0, less
, css
, inline
, reference
(multiple
and once
probably aren't applicable here, but feel free to use them if you find a use case). See examples.
Any new import directives will be immediately available upon release by Less.js.
process
Type: Boolean|Object
Default: false
Process source files as templates before concatenating.
false
- No processing will occur.true
- Process source files using grunt.template.process defaults.options
object - Process source files using grunt.template.process, using the specified options.function(src, filepath)
- Process source files using the given function, called once for each file. The returned value will be used as source code.
(Default processing options are explained in the grunt.template.process documentation)
banner
Type: String
Default: Empty string
This string will be prepended to the beginning of the concatenated output. It is processed using grunt.template.process, using the default options.
(Default processing options are explained in the grunt.template.process documentation)
stripBanners
Type: Boolean|Object
Default: false
Strip JavaScript banner comments from source files.
false
- No comments are stripped.true
-/* ... */
block comments are stripped, but NOT/*! ... */
comments.options
object:- By default, behaves as if
true
were specified. block
- If true, all block comments are stripped.line
- If true, any contiguous leading//
line comments are stripped.
- By default, behaves as if
paths
Type: String|Array
Default: Directory of input file.
Specifies directories to scan for @import
directives when parsing. The default value is the directory of the specified source files. In other words, the paths
option allows you to specify paths for your @import statements in the less
task as an alternative to specifying a path on every @import
statement that appears throughout your LESS files. So instead of doing this:
;
you can do this:
;
rootpath
Type: String
Default: ""
A path to add on to the start of every url resource.
compress
Type: Boolean
Default: false
Compress output by removing some whitespaces.
cleancss
Type: Boolean
Default: false
Compress output using clean-css.
ieCompat
Type: Boolean
Default: true
Enforce the css output is compatible with Internet Explorer 8.
For example, the data-uri function encodes a file in base64 encoding and embeds it into the generated CSS files as a data-URI. Because Internet Explorer 8 limits data-uri
s to 32KB, the ieCompat option prevents less
from exceeding this.
optimization
Type: Integer
Default: null
Set the parser's optimization level. The lower the number, the less nodes it will create in the tree. This could matter for debugging, or if you want to access the individual nodes in the tree.
strictImports
Type: Boolean
Default: false
Force evaluation of imports.
strictMath
Type: Boolean
Default: false
When enabled, math is required to be in parenthesis.
strictUnits
Type: Boolean
Default: false
When enabled, less will validate the units used (e.g. 4px/2px = 2, not 2px and 4em/2px throws an error).
syncImport
Type: Boolean
Default: false
Read @import'ed files synchronously from disk.
dumpLineNumbers
Type: String
Default: false
Configures -sass-debug-info support.
Accepts following values: comments
, mediaquery
, all
.
relativeUrls
Type: Boolean
Default: false
Rewrite urls to be relative. false: do not modify urls.
urlArgs
Type: String
Default: none
Appends string to url tokens for cache busting.
customFunctions
Type: Object
Default: none
Define custom functions to be available within your LESS stylesheets. The function's name must be lowercase and return a primitive type (not an object or array). In the function definition, the first argument is the less object, and subsequent arguments are from the less function call. Values passed to the function are not simple primitive types, rather types defined within less. See the LESS documentation for more information on the available types.
report
Choices: false
|'min'
|'gzip'
Default: false
Either do not report anything, report only minification result, or report minification and gzip results. This is useful to see exactly how well Less is performing, but using 'gzip'
can add 5-10x runtime task execution.
Example ouput using 'gzip'
:
Original: 198444 bytes.
Minified: 101615 bytes.
Gzipped: 20084 bytes.
sourceMap
Type: Boolean
Default: false
Enable source maps.
sourceMapFilename
Type: String
Default: none
Write the source map to a separate file with the given filename.
sourceMapURL
Type: String
Default: none
Override the default url that points to the sourcemap from the compiled css file.
sourceMapBasepath
Type: String
Default: none
Sets the base path for the less file paths in the source map.
sourceMapRootpath
Type: String
Default: none
Adds this path onto the less file paths in the source map.
outputSourceFiles
Type: Boolean
Default: false
Puts the less files into the map instead of referencing them.
version
Type: String
Default: less
(current release)
Specify the directory containing the version of Less.js to use for compiling. You may specify a version at the task level or a different version for each target.
less: options: version: 'vendor/less' styles: files: 'css/style.css': 'src/style.less'
Useful for testing new features included in a beta or alpha release, or for comparing the compiled results from different versions of Less.js.
debug
Type: Boolean
Default: false
Generate some before/after files into a tmp directory so you can inspect what's happening. LESS source files will be saved with .less
extension, and any metadata that's processed will be saved with a .json
extension.
Usage Examples
Basic config for compiling LESS to CSS.
less: development: options: paths: "assets/css" files: "path/to/result.css": "path/to/source.less" production: options: paths: "assets/css" compress: true files: "path/to/result.css": "path/to/source.less"
lessrc
A .lessrc
file must contain valid JSON and look something like this:
A .lessrc.yml
must contain valid YAML and look something like this:
compress: truepaths:- vendor/bootstrap/less
Import directives
Prepend
@import
statements tosrc
files using any of the new@import
directives released after Less.js v1.5.0.
Options are:
reference
: use a less file but do not output itinline
: include the source file in the output but do not process as lessless
: treat the file as a less file, no matter what the file extensioncss
: treat the file as a css file, no matter what the file extension
less: options: paths: 'vendor/bootstrap/less' imports: reference: 'variables.less' 'mixins.less' inline: 'normalize.css' less: 'normalize.css' css: 'foo.css' 'bar.css' files: {}
Compile individual bootstrap components
Use import directives to compile each Bootstrap's LESS components separately.
Using the imports: {}
option and the "files array format" enables us to compile each Bootstrap LESS component without having to add @import "variables.less";
and @import "mixins.less";
to
every file.
less: options: paths: 'vendor/bootstrap/less' imports: reference: 'variables.less' 'mixins.less' components: files: expand: true cwd: 'vendor/bootstrap/less' src: '*.less' dest: 'assets/css/' ext: '.css'
Pass metadata to Lo-Dash templates
Use the metadata
option to pass context to Lo-Dash templates before compiling. For example, let's say you have a config like this:
less: options: metadata: 'src/*.{json,yml}' styles: files: 'css/style.css': 'src/style.less'
and a data file, palette.yml
, with some variables defined:
# palette.yml info: '#000'warning: '#111'danger: '#222'success: '#333'
Then in our LESS file, you can use Lo-Dash templates in LESS variables:
@palette-info: <%= palette.info %>;@palette-warning: <%= palette.warning %>; .swatch-info background: @palette-info;.swatch-warning background: @palette-warning;
Or use the templates in lieu of LESS variables:
.swatch-danger background: <%= palette.danger %>;.swatch-success background: <%= palette.success %>;
Release History
DATE VERSION CHANGES
- 2013-12-31 v0.7.0 Update to use the Less.js v1.6.0 API for
banner
,globalVars
and
modifyVars
. - 2013-12-17 v0.6.0 Adds
globalVars
andmodifyVars
options. See readme and Gruntfile for
examples.,SupportsourceMapURL
,SupportoutputSourceFiles
,Support
sourceMapFilename
,sourceMapBasepath
andsourceMapRootpath
,Upgrade to LESS 1.5 SupportstrictUnits
option,Support sourceMap option,Add
customFunctions
option for defining custom functions within LESS,Output
the source file name on error,yuicompress option now cleancss (Less changed underlying dependency) - 2013-07-29 v0.5.0 Completely refactored the plugin based on grunt-contrib-less.,Add examples
for all features to Gruntfile.,Removed the concat feature.,You can now use
.lessrc
or.lessrc.yml
for externalizing task options.,New
stripBanners
option - 2013-06-12 v0.4.7 Cleaned up a lot of the Gruntfile. Examples are more clear.,New
import
option for prepending import statements to LESS files before compiling.,Newbanner
option for adding banners to generated CSS files. - 2013-03-16 v0.3.0 New option to specify the version of less.js to use for compiling to CSS.
- 2013-03-13 v0.2.3 New options from Less.js 1.4.0
- 2013-02-26 v0.1.0 First commit.
Authors
This project is a fork of the popular grunt-contrib-less by Tyler Kellen. Please use that plugin if you require something stable and dependable.
This fork is maintained by:
Jon Schlinkert
Brian Woodward
License
Copyright (c) 2014 Tyler Kellen, contributors.
Copyright (c) 2014 Jon Schlinkert, contributors.
Released under the MIT license
This file was generated by grunt-verb on April 21, 2014.