Proper Autoprefix Plugin for my less middleware for node expressjs - css

Question

Currently I use less-middleware (https://www.npmjs.com/package/less-middleware). I am not satisfied with this solution, because less-middlware create a compiled css file. I want a memorized solution I can route via expressjs.
Besides, I want to work with a proper autoprefix solution, because there are many nice css technologies I cant use because I would need to much time to add the vendor prefixes.
Do anybody know a better solution for instant less compilation without outputing a separate css file.
Can this solution offer some kind of autoprefixing functionality?
Does offer less-middleware offer an autoprefixing functionality. I have not found something in that direction.

Answer 1

You should try to reformat your question, because of:
Questions asking us to recommend or find a book, tool, software
library, tutorial or other off-site resource are off-topic for Stack
Overflow as they tend to attract opinionated answers and spam.
Instead, describe the problem and what has been done so far to solve
it.
I found https://github.com/toogle/express-less/blob/master/lib/express-less.js according their package.json file, Express LESS middleware uses the latest version of Node Less.
In their code the call less.render() here: https://github.com/toogle/express-less/blob/master/lib/express-less.js#L68 and more information can be found here: http://lesscss.org/usage/#programmatic-usage
Since version 2 of Less you can use plugins. An autoprefix plugin is available at: https://github.com/less/less-plugin-autoprefix
So you should be able to use the follow code:
var express = require('express'),
expressLess = require('express-less'),
autoprefixer = require('less-plugin-autoprefix');
var app = express();
app.use('/less-css', expressLess(__dirname + '/less', { plugins: [autoprefixer] }));
Also see: http://lesscss.org/usage/#plugins-using-a-plugin-in-code
Notice i did not test the above code. I wondered how to set the autoprefixer option. According to https://github.com/plus3network/gulp-less#using-plugins you should use:
var autoprefixerPlugin = require('less-plugin-autoprefix'),
autoprefixer = new autoprefixerPlugin({options});
var app = express();
app.use('/less-css', expressLess(__dirname + '/less', { plugins: [autoprefixer] }));

Answer 2

According to the documentation of Less Engine, the way to use a plugin is the following:
less.render(myCSS, { plugins: [myPlugin] })
Source: http://lesscss.org/usage/#plugins-using-a-plugin-in-code
Then according to the documentation of Less Middleware, the way to add options into second parameter of render() function is the following:
The options.render is passed directly into the less.render with minimal defaults or changes by the middleware.
Source: https://github.com/emberfeather/less.js-middleware#render-options
So according to the documentation of Less Autoprefixer ande the documentation of Express Engine, the definitive and true way to use it is using this code:
var express = require('express'),
lessMiddleware = require('less-middleware'),
lessPluginAutoprefix = require('less-plugin-autoprefix'),
app = express(),
autoprefixPlugin = new lessPluginAutoprefix({
browsers: ["last 2 versions"]
});
app.use(lessMiddleware(path.join(__dirname, 'public'), {
render: {
plugins: [
autoprefixPlugin
]
}
}));
This was implemented and tested in the NodeAtlas NPM module.