headerblock/index.js

Simple module designed to create header blocks for source files from package.json data

/* jshint node: true */

/**
  # headerblock

  This is a small helper module that is used within
  [Interleave](https://github.com/buildjs/interleave) to generate header
  block comments for source files.

  ## Example Usage

  ```js
  var headerblock = require('headerblock');
  var packageData = require('./package.json');

  // call headerblock with artificial data
  headerblock(packageData, function(err, output) {
    // generated, js block commented header generated and in output
  });
  ```

  If you want to generate a header block for a language such as
  [CoffeeScript](https://coffee-script.org) then you can specify the filetype:

  ```js
  var headerblock = require('headerblock');
  var packageData = require('./package.json');

  // call headerblock with artificial data
  headerblock(packageData, { filetype: 'coffee' }, function(err, output) {
    // generated, coffeescript block commented header generated and in output
  });
  ```

  ## Sample Generated Header Blocks

  To be completed.
**/

var async = require('async');
var fs = require('fs');
var path = require('path');
var _existsSync = fs.existsSync || path.existsSync;
var commentwrap = require('./commentwrap');
var _ = require('underscore');
var defaultData = {
  name: '',
  description: '',
  generator: 'headerblock',
  url: null,
  builddate: new Date().toISOString(),
  md5: null,
  copyright: null,
  licenses: []
  };

module.exports = function(data, opts, callback) {
  var templatePaths = [ path.resolve(__dirname, 'templates', 'default.txt') ];
  var output;
  
  // handle the 2 args case
  if (typeof opts == 'function') {
    callback = opts;
    opts = {};
  }
  
  // ensure we have opts
  opts = opts || {};
  
  // ensure the data has defaults
  data = _.defaults({}, data, defaultData);

  // initialise the default version (using this technique to get around
  // versionit being clever)
  data.version = data.version || '';
  
  // if we have a template option specified, then add some additional paths
  if (opts.template) {
    templatePaths.shift(path.resolve(__dirname, 'templates', opts.template + '.txt'));
    templatePaths.shift(path.resolve(opts.template));
  }
  
  // find the first valid template
  async.detect(templatePaths, fs.exists || path.exists, function(templatePath) {
    // read the template file
    fs.readFile(templatePath, 'utf8', function(err, content) {
      if (err) return callback(err);
      
      // add the packagename leader if it doesn't exist already
      if (data.name) {
        opts.leader = ' ~' + data.name + '~';
      }
      
      try {
        // fire the callback
        return callback(null, commentwrap(opts, _.template(content, _.defaults({}, data, opts))));
      }
      catch (e) {
        return callback(e);
      }
    });
  });
};