# pkginfo.js

¶ |
    /*
     * pkginfo.js: Top-level include for the pkginfo module
     *
     * (C) 2011, Charlie Robbins
     *
     */

    var fs = require('fs'),
        path = require('path');
¶

### function pkginfo ([options, 'property', 'property' ..])

#### @pmodule {Module} Parent module to read from.

#### @options {Object|Array|string} Optional Options used when exposing properties.

#### @arguments {string...} Optional Specified properties to expose.

Exposes properties from the package.json file for the parent module on it's exports. Valid usage:

`require('pkginfo')()`

`require('pkginfo')('version', 'author');`

`require('pkginfo')(['version', 'author']);`

`require('pkginfo')({ include: ['version', 'author'] });`

    var pkginfo = module.exports = function (pmodule, options) {
      var args = [].slice.call(arguments, 2).filter(function (arg) {
        return typeof arg === 'string';
      });

¶ Parse variable arguments |
      if (Array.isArray(options)) {
¶ If the options passed in is an Array assume that it is the Array of properties to expose from the on the package.json file on the parent module. |
        options = { include: options };
      }
      else if (typeof options === 'string') {
¶ Otherwise if the first argument is a string, then assume that it is the first property to expose from the package.json file on the parent module. |
        options = { include: [options] };
      }
¶ Setup default options |
      options = options || { include: [] };

      if (args.length > 0) {
¶ If additional string arguments have been passed in then add them to the properties to expose on the parent module. |
        options.include = options.include.concat(args);
      }

      var pkg = pkginfo.read(pmodule, options.dir).package;
      Object.keys(pkg).forEach(function (key) {
        if (options.include.length > 0 && !~options.include.indexOf(key)) {
          return;
        }

        if (!pmodule.exports[key]) {
          pmodule.exports[key] = pkg[key];
        }
      });

      return pkginfo;
    };
¶

### function find (dir)

#### @pmodule {Module} Parent module to read from.

#### @dir {string} Optional Directory to start search from.

Searches up the directory tree from `dir` until it finds a directory which contains a `package.json` file.

    pkginfo.find = function (pmodule, dir) {
      dir = dir || pmodule.filename;
      dir = path.dirname(dir);

      var files = fs.readdirSync(dir);

      if (~files.indexOf('package.json')) {
        return path.join(dir, 'package.json');
      }

      if (dir === '/') {
        throw new Error('Could not find package.json up from: ' + dir);
      }

      return pkginfo.find(dir);
    };

¶

### function read (pmodule, dir)

#### @pmodule {Module} Parent module to read from.

#### @dir {string} Optional Directory to start search from.

Searches up the directory tree from `dir` until it finds a directory which contains a `package.json` file and returns the package information.

    pkginfo.read = function (pmodule, dir) {
      dir = pkginfo.find(pmodule, dir);

      var data = fs.readFileSync(dir).toString();

      return {
        dir: dir,
        package: JSON.parse(data)
      };
    };

¶ Call `pkginfo` on this module and expose version. |
    pkginfo(module, {
      dir: __dirname,
      include: ['version'],
      target: pkginfo
    });