deepstream.io-storage-postgres/src/transform-data.js

A deepstream.io storage connector for use with deepstream

"use strict"

/**
 * This method is for the storage connector, to allow queries to happen more naturally
 * do not use in cache connectors
 *
 * Inverts the data from the deepstream structure to reduce nesting.
 *
 * { _v: 1, _d: { name: 'elasticsearch' } } -> { name: 'elasticsearch', __ds = { _v: 1 } }
 *
 * @param  {String} value The data to save
 *
 * @private
 * @returns {Object} data
 */
module.exports.transformValueForStorage = function ( value ) {
  value = JSON.parse( JSON.stringify( value ) )

  var data = value._d
  delete value._d

  if( data instanceof Array ) {
    data = {
      __dsList: data,
      __ds: value
    }
  } else {
    data.__ds = value
  }

  return data
}

/**
 * This method is for the storage connector, to allow queries to happen more naturally
 * do not use in cache connectors
 *
 * Inverts the data from the stored structure back to the deepstream structure
 *
 * { name: 'elasticsearch', __ds = { _v: 1 } } -> { _v: 1, _d: { name: 'elasticsearch' } }
 *
 * @param  {String} value The data to transform
 *
 * @private
 * @returns {Object} data
 */
module.exports.transformValueFromStorage = function( value ) {
  value = JSON.parse( JSON.stringify( value ) )

  var data = value.__ds
  delete value.__ds

  if( value.__dsList instanceof Array ) {
    data._d = value.__dsList
  } else {
    data._d = value
  }

  return data
}