Preprocessor.js NPM

Preprocessor.js - A JavaScript preprocessor

Provides a JavaScript source file preprocessor.

Directives

Includes (always relative to the baseDirectory, defaults to "."):
```
...
// #include "path/to/file.js"
...
```

Static conditions:

// #ifdef FULL
console.log("Including extension");
// #include "path/to/extension.js"
// #else
console.log("Not including extension");
// #endif

Inverse static conditions:

// #ifndef FULL
console.log("Not including extension");
// #else
console.log("Including extension");
// #include "path/to/extension.js"
// #endif

Evaluable conditions:

// #if 1==2
console.log("1==2");
// #elif 2==2
console.log("2==2");
// #endif

Inline variables and functions:

// #define var PI=Math.PI
// #define function RADTODEG(x){return x*180/PI}
var angle = // #put RADTODEG(3)+";"

Writing the result of evaluated expressions:

var version = // #put '"'+VERSION+'";"'
var str = // #put "\"Hello world!\";"
var onePlusOne = // #put (1+1)+";"

Features

CommonJS compatible
RequireJS/AMD compatible
node.js compatible, also available via npm
Fully documented using jsdoc3
Well tested through tape
Zero production dependencies
Small footprint

Command line utility

Install via npm: npm -g install preprocessor

Command line

Usage: preprocess sourceFile [baseDirectory] [-myKey[=myValue], ...] [--verbose] [> outFile]

preprocess Source.js . -FULL=true > Source.full.js

API

The API is quite simple:

var result = new Preprocessor(
    mainFileSource,
    baseDirectoryOrIncludes
).process(defines);

with baseDirectoryOrIncludes being either a string containing the path to the base directory or an object of included sources by filename. When running in a browser, only the later is supported.

node.js / CommonJS

var Preprocessor = require("preprocessor");
var source = "..."; // e.g. through fs.readFile
var pp = new Preprocessor(source, ".");
console.log(pp.process({
    FULL: true
}));

RequireJS / AMD

require(["/path/to/Preprocessor.js"], function(Preprocessor) {
    var source = "..."; // e.g. through fs.readFile / $.ajax
    var pp = new Preprocessor(source, ".");
    console.log(pp.process({
        FULL: true
    }));
});

Browser / shim

Note: To use the #include directive in the browser, do not specify the base directory but an object of included sources by filename:

<script src="//raw.github.com/nashdot/Preprocessor.js/master/Preprocessor.js"></script>

var Preprocessor = nashdot.Preprocessor;
var source = "..."; // e.g. through. $.ajax
var pp = new Preprocessor(source, {
    "./includes/extension.js": "var myVar = 2;" // <- #include "includes/extension.js"
});
alert(pp.process({
    FULL: true
}));

Using includes instead of a base directory like shown in the example above is supported regardless of the platform you are on.