transacemail/lib/Mail.js

Transactional Email & Templated Email for NodeJS

var path = require('path');
var fs = require('fs');
var _ = require('lodash');
var juice = require('juice');
var deepExtend = require('deep-extend');

// Support for Node v0.6
fs.existsSync = fs.existsSync || function existsSync(filePath) {
  try {
    fs.statSync(filePath);
  } catch (err) {
    if (err.code === 'ENOENT') {
      return false;
    }
  }
  return true;
};

/**
 * Mail constructor
 * @param {Object} templateEngine Template Engine that will be used to render the mail
 * @param {String} metaPath       Path to the mail meta file
 * @private
 */
function Mail(templateEngine, metaPath) {
  if (!templateEngine) {
    throw new Error("Mail(templateEngine, metaPath): TemplateEngine is undefined.");
  }

  this.styles = [];
  this._dir = path.dirname(metaPath);
  this._name = path.basename(metaPath, Mail.DEFAULT_META_EXT);
  this._mailing = null;
  this.templateEngine = templateEngine;
  this.html = null;
  this.text = null;
  this.sendIf = function (fn) {
    return fn(false);
  };
}

/**
 * Meta file extension
 * @type {String}
 */
Mail.DEFAULT_META_EXT = '.meta.js';

/**
 * HTML mail format extension
 * @type {String}
 */
Mail.DEFAULT_HTML_EXT = '.html';

/**
 * TEXT mail format extension
 * @type {String}
 */
Mail.DEFAULT_TEXT_EXT = '.txt';

/**
 * _readMeta
 * @private
 * @return {[type]} [description]
 */
Mail.prototype._readMeta = function () {
  var metaPath = path.resolve(this._dir, this._name + Mail.DEFAULT_META_EXT);
  if (!fs.existsSync(metaPath)) {
    throw new Error("Meta file not found: " + metaPath);
  }
  deepExtend(this, require(metaPath));
  return this;
};

Mail.prototype.getName = function () {
  return this._name;
};

Mail.prototype.getMailing = function () {
  return this._mailing;
};

/**
 * _readHTML
 * @private
 * @return {[type]} [description]
 */
Mail.prototype._readHTML = function () {
  var htmlPath = path.resolve(this._dir, this._name + Mail.DEFAULT_HTML_EXT);
  if (!fs.existsSync(htmlPath)) {
    return this;
  }
  this.html = fs.readFileSync(htmlPath).toString('utf8');
  return this;
};

Mail.prototype._mergeCssErr = function () {
  throw new Error("Aww meeeeen... An error occured while inlining the CSS." +
    "\nCheck that your HTML or TEXT version does not contain things like '<%' because Juice use JSDom underneath and it removes them." +
    "\nCheck that your css is valid, if you think that is a bug, please report the issue to the Juice library.");
};

Mail.prototype._mergeCss = function () {
  var stylesheets = this.styles
    .map(function (style_path) {
      return path.resolve(this._dir, style_path);
    }.bind(this))
    .filter(fs.existsSync.bind(fs))
    .map(function (path) {
      return fs.readFileSync(path).toString('utf8');
    });

  if (this.html && this.html.length > 0) {
    var htmlWithInlinedCss = juice(this.html, {
      extraCss: stylesheets.join('\n')
    });
    if (htmlWithInlinedCss.length === 0) {
      this._mergeCssErr();
    }
    this.html = htmlWithInlinedCss;
  }

  if (this.text && this.text.length > 0) {
    var textWithInlinedCss = juice(this.text, {
      extraCss: stylesheets.join('\n')
    });
    if (textWithInlinedCss.length === 0) {
      this._mergeCssErr();
    }
    this.text = textWithInlinedCss;
  }

  return this;
};

/**
 * _readText
 * @private
 * @return {[type]} [description]
 */
Mail.prototype._readText = function () {
  var textPath = path.resolve(this._dir, this._name + Mail.DEFAULT_TEXT_EXT);
  if (!fs.existsSync(textPath)) {
    return this;
  }
  this.text = fs.readFileSync(textPath).toString('utf8');
  return this;
};

/**
 * Compile the mail with the specified arguments
 * @param  {[type]} args [description]
 * @return {[type]}      [description]
 * @private
 */
Mail.prototype._compileWith = function (args) {
  var mail = _.clone(this);
  // Html
  if (this.html && !this.tplHTML) {
    this.tplHTML = this.templateEngine.compile(this.html);
  }
  if (this.html) {
    mail.html = this.templateEngine.exec(this.tplHTML, args);
  }
  // Text
  if (this.text && !this.tplText) {
    this.tplText = this.templateEngine.compile(this.text);
  }
  if (this.text) {
    mail.text = this.templateEngine.exec(this.tplText, args);
  }
  // Append data
  mail.data = args;
  return mail;
};

/**
 * Mail Factory
 * @param {Object} templateEngine Template Engine that will be used to render the mail
 * @param {String} metaPath Path to the mail meta file
 * @return {Mail} A Mail object
 */
Mail.Factory = function (templateEngine, metaPath) {
  return new Mail(templateEngine, metaPath)
    ._readMeta()
    ._readHTML()
    ._mergeCss()
    ._readText();
};

/**
 * Export Mail
 * @type {Function}
 * @private
 */
module.exports = Mail;