assemble-less
Version:
Compile LESS to CSS. Adds experimental features that extend Less.js for maintaining UI components, 'bundles' and themes. From Jon Schlinkert, core team member of Less.js. This project is a fork of the popular grunt-contrib-less plugin by the talented Tyler Kellen. Please use that plugin if you require something stable and dependable.
334 lines (285 loc) • 10.2 kB
JavaScript
/*
* NOTE that most of this code is from grunt-contrib-less. PLEASE USE
* THAT PROJECT IF YOU REQUIRE SOMETHING STABLE AND RELIABLE. This
* project is focused on testing experimental features, some of which
* may be removed in the future.
*
*
* grunt-contrib-less
* http://gruntjs.com/
* Copyright (c) 2013 Tyler Kellen, contributors
* Licensed under the MIT license.
*
*
* assemble-less
* http://github.com/assemble/assemble-less
* Copyright (c) 2013 Jon Schlinkert, Brian Woodward, contributors
* Licensed under the MIT license.
*/
;
// Node.js
var path = require('path');
// node_modules
var async = require('async');
var _ = require('lodash');
module.exports = function(grunt) {
// Internal lib.
var contrib = require('grunt-lib-contrib').init(grunt);
var comment = require('./lib/comment').init(grunt);
var less = false;
var lessOptions = {
parse: [
'dumpLineNumbers',
'filename',
'optimization',
'paths',
'relativeUrls',
'rootpath',
'strictImports',
'syncImport'
],
render: [
'cleancss',
'compress',
'ieCompat',
'outputSourceFiles',
'sourceMap',
'sourceMapBasepath',
'sourceMapFilename',
'sourceMapRootpath',
'sourceMapURL',
'strictMath',
'strictUnits'
]
};
grunt.registerMultiTask('less', 'Compile LESS files to CSS, with experimental features.', function() {
var done = this.async();
// Task options.
var options = this.options({
banner: '',
imports: {},
mergeMetadata: true,
metadata: [],
process: true,
stripBanners: false,
version: 'less'
});
// Less.js defaults.
var defaults = {
globalVariables: '',
modifyVariables: '',
processImports: true,
strictMath: false,
strictUnits: false,
verbose: true
};
// By default, metadata at the task and target levels is merged.
// Set `mergeMetadata` to false if you do not want metadata to be merged.
if (options.mergeMetadata !== false) {
options.metadata = mergeOptionsArrays(this.target, 'metadata');
}
// Process banner.
options.banner = grunt.template.process(options.banner) || '';
// Read Less.js options from a specified lessrc file.
if (options.lessrc) {
var fileType = options.lessrc.split('.').pop().toLowerCase();
if (fileType === 'yaml' || fileType === 'yml') {
// if .lessrc.yml is specified, then parse as YAML
options = _.merge(defaults, options, grunt.file.readYAML(options.lessrc));
grunt.log.writeln('options: ', options);
} else if (fileType === 'lessrc') {
// otherwise, parse as JSON
options = _.merge(defaults, options, grunt.file.readJSON(options.lessrc));
grunt.log.writeln('options: ', options);
}
} else {
options = _.extend(defaults, options);
}
// Load less version specified in options, else load default
grunt.verbose.writeln('Loading less from ' + options.version);
try {
less = require(options.version);
} catch (err) {
var lessPath = path.join(process.cwd(), options.version);
grunt.verbose.writeln('lessPath: ', lessPath);
less = require(lessPath);
grunt.log.success('\nRunning Less.js v', path.basename(options.version) + '\n');
}
grunt.verbose.writeln('Less loaded');
if (this.files.length < 1) {
grunt.verbose.warn('Destination not written because no source files were provided.');
}
async.forEachSeries(this.files, function(f, nextFileObj) {
var destFile = f.dest;
var files = f.src.filter(function(filepath) {
// Warn on and remove invalid source files (if nonull was set).
if (!grunt.file.exists(filepath)) {
grunt.log.warn('Source file "' + filepath + '" not found.');
return false;
} else {
return true;
}
});
if (files.length === 0) {
if (f.src.length < 1) {
grunt.log.warn('Destination not written because no source files were found.');
}
// No src files, goto next target. Warn would have been issued above.
return nextFileObj();
}
var compiledMax = [];
var compiledMin = [];
async.concatSeries(files, function(file, next) {
compileLess(file, options, function(css, err) {
if (!err) {
if (css.max) {
compiledMax.push(css.max);
}
compiledMin.push(css.min);
next();
} else {
nextFileObj(err);
}
}, function (sourceMapContent) {
grunt.file.write(options.sourceMapFilename, sourceMapContent);
grunt.log.writeln('File ' + options.sourceMapFilename.cyan + ' created.');
});
}, function() {
if (compiledMin.length < 1) {
grunt.log.warn('Destination not written because compiled files were empty.');
} else {
var min = compiledMin.join(options.cleancss ? '' : grunt.util.normalizelf(grunt.util.linefeed));
grunt.file.write(destFile, options.banner + min);
grunt.log.writeln('File ' + destFile.cyan + ' created.');
// ...and report some size information.
if (options.report) {
contrib.minMaxInfo(min, compiledMax.join(grunt.util.normalizelf(grunt.util.linefeed)), options.report);
}
}
nextFileObj();
});
}, done);
});
var compileLess = function(srcFile, options, callback, sourceMapCallback) {
options = _.extend({
filename: srcFile,
process: options.process
}, options);
options.paths = options.paths || [path.dirname(srcFile)];
// Prepend variables to source files
var globalVariables = [];
// Append variables to source files
var modifyVariables = [];
var globalVars = options.globalVars || {};
var modifyVars = options.modifyVars || {};
_.forIn(globalVars, function(value, key) {
globalVariables.push('@' + key + ': ' + value + ';');
});
_.forIn(modifyVars, function(value, key) {
modifyVariables.push('@' + key + ': ' + value + ';');
});
// Process imports and any templates.
var importDirectives = [];
function processDirective(list, directive) {
_(options.paths).forEach(function(filepath) {
_.each(list, function(item) {
item = path.join(filepath, item);
grunt.file.expand(grunt.template.process(item)).map(function(ea) {
importDirectives.push('@import' + ' (' + directive + ') ' + '"' + ea + '";');
});
});
});
}
for (var directive in options.imports) {
if (options.imports.hasOwnProperty(directive)) {
var list = options.imports[directive];
list = Array.isArray(list) ? list : [list];
processDirective(list, directive);
}
}
importDirectives = importDirectives.join('\n');
modifyVariables = modifyVariables.join('\n');
globalVariables = globalVariables.join('\n');
var css;
var srcCode = importDirectives + globalVariables + grunt.file.read(srcFile) + modifyVariables;
// Process files as templates if requested.
var metadata = {};
var metadataFiles = grunt.file.expand(options.metadata);
metadataFiles.forEach(function(metadataFile) {
var filename = path.basename(metadataFile, path.extname(metadataFile));
var fileExt = metadataFile.split('.').pop();
if (fileExt === 'yml' || fileExt === 'yaml') {
metadata[filename] = grunt.file.readYAML(metadataFile);
} else {
metadata[filename] = grunt.file.readJSON(metadataFile);
}
});
metadata = _.merge({}, grunt.config.data, grunt.task.current.data.options, metadata);
metadata = grunt.config.process(metadata);
if (options.process === true) {options.process = {};}
if (typeof options.process === 'function') {
srcCode = options.process(srcCode, srcFile);
} else if (options.process) {
srcCode = grunt.template.process(srcCode, {data: metadata});
}
// Strip banners if requested.
if (options.stripBanners) {
srcCode = comment.stripBanner(srcCode, options.stripBanners);
}
var parser = new less.Parser(_.pick(options, lessOptions.parse));
parser.parse(srcCode, function(parse_err, tree) {
if (parse_err) {
lessError(parse_err, srcFile);
callback('', true);
}
// Load custom functions
if (options.customFunctions) {
Object.keys(options.customFunctions).forEach(function(name) {
less.tree.functions[name.toLowerCase()] = function() {
var args = [].slice.call(arguments);
args.unshift(less);
return new less.tree.Anonymous(options.customFunctions[name].apply(this, args));
};
});
}
var minifyOptions = _.pick(options, lessOptions.render);
if (minifyOptions.sourceMapFilename) {
minifyOptions.writeSourceMap = sourceMapCallback;
}
try {
css = minify(tree, minifyOptions);
callback(css, null);
} catch (e) {
lessError(e, srcFile);
callback(css, true);
}
});
};
/**
* Function from assemble
* https://github.com/assemble/assemble
*/
var mergeOptionsArrays = function(target, name) {
var taskArray = grunt.config([grunt.task.current.name, 'options', name]) || [];
var targetArray = grunt.config([grunt.task.current.name, target, 'options', name]) || [];
return _.union(taskArray, targetArray);
};
var formatLessError = function(e) {
var pos = '[' + 'L' + e.line + ':' + ('C' + e.column) + ']';
return e.filename + ': ' + pos + ' ' + e.message;
};
var lessError = function(e, file) {
var message = less.formatError ? less.formatError(e) : formatLessError(e);
grunt.log.error(message);
grunt.fail.warn('Error compiling ' + file);
};
var minify = function(tree, options) {
var result = {
min: tree.toCSS(options)
};
if (!_.isEmpty(options)) {
result.max = tree.toCSS();
}
return result;
};
};