通过节点脚本将Less转换为css

Question

找到的解决方案，请参阅此后的底部

尝试使用nodeJS 构建脚本来构建LESS(LESS css)

我正试图使用节点脚本从less构建一个css文件，我的文件结构无法更改，看起来像：

/public/css/app.css
/resources/assets/less/xenon.less
/quickSync/02_lessCompiler.js

less文件的内容有效地包括与.less文件本身相同级别的其他less文件，并在文件结构中继续，例如：

// Import Bootstrap Variables & Mixins
@import "bs-less/variables.less";
@import "bs-less/mixins.less";
// LessHat
@import "other-less/lesshat.less";
... etc etc

从上面的链接我尝试了以下内容：

var less = require( 'less' );
var fs = require( 'fs' );
var path = require('path');
var basePath = __dirname + '/..';
var lessPath    = basePath + '/resources/assets/less/xenon.less',
outputPath  = basePath + '/public/css/app.css';
fs.readFile( lessPath ,function(error,data){
data = data.toString();
console.log( error );
console.log( data );
less.render(data, function (e, css) {
console.log( e );
console.log( css );
fs.writeFile( outputPath, css, function(err){
if( err ){
console.log(err );
}
console.log('done');
});
});
});

上述解决方案的控制台输出为：

null
// Import Bootstrap Variables & Mixins
@import "bs-less/variables.less";
@import "bs-less/mixins.less";
// LessHat
@import "other-less/lesshat.less";
// Xenon Basic UI
@import "xenon-core.less";
// Forms
@import "xenon-forms.less";
// Xenon Extra Components
@import "xenon-components.less";
// Xenon Skins
@import "xenon-skins.less";
{ [Error: 'xenon-skins.less' wasn't found. Tried - xenon-skins.less,xenon-skins.less]
type: 'File',
filename: 'input',
index: 311,
line: 18,
callLine: NaN,
callExtract: undefined,
column: 0,
extract: [ '// Xenon Skins', '@import "xenon-skins.less";', undefined ],
message: ''xenon-skins.less' wasn't found. Tried - xenon-skins.less,xenon-skins.less',
stack: undefined }
undefined
done

但是，输出文件只读取

undefined
undefined

然后我发现了这个家伙的博客：http://onedayitwillmake.com/blog/2013/03/compiling-less-from-a-node-js-script/并尝试了以下操作：

var less = require( 'less' );
var fs = require( 'fs' );
var path = require('path');
var lessPath    = basePath + '/resources/assets/less/xenon.less',
outputPath  = basePath + '/public/css/app.css';
//ensure directory exists
var ensureDirectory = function (filepath) {
var dir = path.dirname(filepath);
var existsSync = fs.existsSync || path.existsSync;
if (!existsSync(dir)) {
fs.mkdirSync(dir);
}
};
fs.readFile( lessPath, function(error, data){
var dataString = data.toString();

var options = {
paths         : [basePath + '/resources/assets/less'],  // .less file search paths
outputDir     : basePath + '/public/css',               // output directory, note the '/'
optimization  : 1,                                      // optimization level, higher is better but more volatile - 1 is a good value
filename      : "xenon.less",                              // root .less file
compress      : false,                                  // compress?
yuicompress   : false                                   // use YUI compressor?
};
console.log( options );
options.outputDir = path.resolve( process.cwd(), options.outputDir) + "/";
ensureDirectory( options.outputDir );
var parser = new less.Parser(options);
console.log( 'parsing' );
parser.parse( dataString, function ( error, cssTree ) {
if ( error ) {
console.log( 'Error compiling less:' );
console.log( error );
return false;
}
// Create the CSS from the cssTree
var cssString = cssTree.toCSS({
compress: options.compress,
yuicompress: options.yuicompress
});
fs.writeFile(outputPath, cssString, function (err) {
logTime('Compiled less: ' + outputPath);
//run the mai passed callback function
callback();
});
});
});

然而，这是一个错误的输出：

D:myprojectnode_moduleslessliblessparserparser.js:117
imports.contents[fileInfo.filename] = str;
^
TypeError: Cannot read property 'contents' of undefined
at Object.Parser.parse (D:myprojectnode_moduleslessliblessparserparser.js:117:20)
at D:myprojectquickSync2_lessCompiler.js:51:16
at FSReqWrap.readFileAfterClose [as oncomplete] (fs.js:380:3)

这让我疯了，你就这么说吧：

require('node-sass').render({
file: scssPath,
outFile: outputPath,
outputStyle: 'expanded',
sourceComments: true
}, function( err, result ){
//write result to disk.
});

使用无节点编译器构建css最简单的方法是什么？

解决方案：

fs.readFile( lessPath ,function(error,data){
data = data.toString();
less.render(data, {
paths: [ basePath + '/resources/assets/less/' ]
},function (e, css) {
fs.writeFile( outputPath, css.css, function(err){
if( err ){
console.log(err );
}
console.log('done');
});
});
});

Answer 1

第一个在这里工作，也许你应该

console.log(error)

在readFile回调中，很可能您的路径错误，无法打开文件。