json-schema-dynamo

#json-schema-dynamo# Just an easier way to transform objects into DynamoDB items

var transformers = require('json-schema-dynamo')

var schema = {
  type: 'object',
  properties: {
    id: {
      type: 'string'
    },
    createDate: {
      type: 'date'
    },
    name: {
      type: 'string'
    },
    active: {
      type: 'boolean'
    },
    likes: {
      type: 'number'
    },
    types: {
      type: 'array',
      items: {
        type: 'string'
      }
    },
    userIds: {
      type: 'array',
      items: {
        type: 'number'
      }
    }
  }
}

var model = {
  id: 'asdf',
  createDate: new Date(),
  name: 'asdffdas',
  likes: 1,
  active: true,
  types: ['qwerty', 'ytrewq'],
  userIds: [1, 2, 3, 4, 5, 6, 7]
}

var item = transformers.fromModelToDynamoItem(schema, model)
console.log(item)
/*
  {
    id: {
      S: 'asdf'
    },
    createDate: {
      N: '1928383'
    },
    name: {
      S: 'asdffdas'
    },
    likes: {
      N: '1'
    },
    active: {
      B: 'true'
    },
    types: {
      SS: ['qwerty', 'ytrewq']
    },
    userIds: {
      SN: ['1', '2', '3', '4', '5', '6', '7']
    }
  }
*/

var newModel = transformers.fromDynamoItemToModel(schema, item)
console.log(newModel)
/*
  {
    id: 'asdf',
    createDate: <Date>,
    name: 'asdffdas',
    active: true,
    likes: 1
    types: ['qwerty', 'ytrewq'],
    userIds: [1, 2, 3, 4, 5, 6, 7]
  }
*/

Currently it supports: string, number, integer, boolean, array of strings, array of numbers, and lists

There is also custom support for dates. You can define an attribute as a date type which will be transformed into an N in Dynamo and then back into a date when retrieved.

Both transforms will also validate your model against your schema as well