Compiling LESS into CSS with Gradle without installing a plug-in - less

Question

This may seem like an odd question. I want to compile LESS into CSS without installing a plug-in into my local gradle. There are several gradle plug-ins out there that compile LESS into CSS, which is great, but I would like to compile and use the plug-ins at runtime rather than install them prior.
Is this possible? If there was a standard plug-in like for CoffeeScript, it would be no big deal and easy, but there isn't one for LESS. I'm rather new to Gradle, so I'm unsure of how to move forward. The obvious solution is to bloody install the plug-in, but given a constraint that I can't, is it possible to compile/use it at runtime?
https://github.com/koenongena/lesscss-gradle-plugin
https://github.com/skhome/gradle-less-plugin
https://github.com/msgilligan/gradle-lesscss-plugin

Answer 1

In most cases you don't install plugins into your Gradle installation. Rather, you declare the usage of the plugin as part of your build.gradle. At build runtime, it then resolves any plugins that are needed for your build script, loads them, and then runs the build. The particular plugins you listed are a bit unusual in that (as far as I can tell) they haven't yet been published in a publicly accessible Maven repository (such as Maven Central or Bintray). After a quick search, I found one that appears to be in Maven Central:
https://github.com/obecker/gradle-lesscss-plugin
To use it, you don't need to install anything ahead of time. Instead, you declare it in your build.gradle like this:
buildscript {
repositories {
mavenCentral()
}
dependencies {
classpath 'de.obqo.gradle:gradle-lesscss-plugin:1.0-1.3.3'
}
}
apply plugin: 'lesscss'
If you don't want to use a plugin, you can pretty easily compile LESS files in Gradle without using any plugin at all. That's because the Gradle plugin architecture builds on exactly the same DSL and deep API as you use in build scripts. The main difference is one of intent; a plugin has been packaged in a way that is intended for re-use in other projects.
The bare minimum needed is access to a library that performs LESS compilation, and a declaration of a task that uses it. Here's a quick example using lesscss-java. It only compiles a single LESS file, but it should be easy to extend for whatever your requirements are.
build.gradle:
buildscript {
repositories {
mavenCentral()
}
dependencies {
classpath "org.lesscss:lesscss:1.3.0"
}
}
task lessCompile << {
def compiler = new org.lesscss.LessCompiler()
compiler.compile(file("some.less"), file("some.css"))
}
some.less:
#mainColor: black;
body {
background-color: #mainColor;
}
After running gradle lessCompile, the result is some.css:
body {
background-color: #000000;
}