cray/editor/index.js

Epub parser

/**
 * @author: Akshay
 * @date: 12/13/2015
 * @github: https://github.com/akshayKrSingh
 * @npm: https://npmjs.com/~akshaysingh
 */
var Writable = require('stream').Writable;
var EpubHelpers = require('../epub/helpers');
var utils = require('util');
var path = require('path');
var stripTags = require('striptags');
var js2xml = require('js2xmlparser');
var fs = require('fs-extra');
var pretty = require('pretty-data').pd;

function Editor(options) {
  if (!(this instanceof Editor)) {
    return new Editor(options);
  }

  this.options = options || {};
  this._$$count = 0;
  this._$$Spines = {total: 0, '_struct': {spine: []}};
  this.opf = {
    root: '',
    path: ''
  };

  Writable.call(this, options);
}

utils.inherits(Editor, Writable);

var proto = Editor.prototype;

proto._write = function(chunk, enc, next) {
  var data = JSON.parse(chunk.toString()), epub = EpubHelpers(), self = this;

  if (data.spineLength) {self._$$Spines.total = data.spineLength;}

  if (data.type === 'EPUB#spine') {
    self._$$Spines._struct.spine.push({
      '@': {
        id: data.idref,
        href: data.href
      },
      "#": stripTags(data.file)
    });
    //console.log(stripTags(data.file));
  }

  if (self._$$count === self._$$Spines.total - 1) {
    fs.outputFile(path.resolve(data.base, 'META-INF/search.xml'),
      pretty.xml(js2xml('search', self._$$Spines._struct)),
      function(err) {
        if (err) {
          return self._destroy(err);
        }
      });

    self._autoDrain();
  } else if (data.type === 'EPUB#spine') {
    self._$$count++;
  }

  next();
};

/**
 * @name: _autoDrain()
 * @description:
 *  Removes Reader properties used during stream _read & _write process.
 *  _autoDrain() is called automatically at the end of Writable Stream.
 */
proto._autoDrain = function() {
  var self = this;
  self._$$Spines = {total: 0, '_struct': {spine: []}};
  self._$$count = 0;
};

proto._destroy = function(err) {
  // Allows to destruct the stream, nothing will be emitted after this point. No Warnings or Errors
  this.writeable = false;
  this._$$destroyed = true;
  this.emit('close', err);
};

module.exports = Editor;