DynamoDB-Mapper

A fast, easy to use Amazon DynamoDB to Javascript Object mapper.

Installation

``bash
$ npm install dynamodb-mapper
`

Features

* Agnostic to Amazon client
* Focus on high performance
* Test coverage
* Explicit mapping definition to prevent data leaks

Data Types

| Data Type | Amazon Type | DynamoDB-Mapper Type | Supported | Serialization |
| --------- | ----------- | -------------------- | --------- | ------------- |
| String | S | S | Yes | Native |
| Date | S | D | Yes | ISO String |
| Number | N | N | Yes | Native |
| Map | M | M | Yes | Native |
| List | L | L | Yes | Native |
| Object | S | O | Yes | JSON String |
| String Set | SS | SS | Yes | Native |
| Number Set | NS | n/a | No | n/a |
| Binary | B | n/a | No | n/a |
| Binary Set | BS | n/a | No | n/a |
| Boolean | BOOL | n/a | No | n/a |
| NULL | NULL | n/a | No | n/a |

AWS SDK Data Type Documentation:

* Data Model
* AttributeValue

Getting Started

`js
var aws = require('aws-sdk');
aws.config.loadFromPath('./config.json');
var dynamodb = new aws.DynamoDB();
var dynamodbMapper = require('dynamodb-mapper');

// build your map
var myMap = {
myStringHashKey: { type: 'S', hashKey: true },
myDateRangeKey: { type: 'D', rangeKey: true },
myString: { type: 'S' },
myDate: { type: 'D' },
myNumber: { type: 'N' },
myMap: {
type: 'M',
map: {
myMapString: { type: 'S' },
myMapDate: { type: 'D' },
/ ... /
},
},
myJsonAsString: { type: 'O' },
myListOfNumbers: {
type: 'L',
valueMap: { type: 'N' },
},
myListOfMaps: {
type: 'L',
valueMap: {
type: 'M',
map: {
myMapString: { type: 'S' },
myMapDate: { type: 'D' },
/ ... /
},
},
},
myStringSet: { type: 'SS' },
};

// create your mapper
// NOTE: you should do it once and reuse it
var myMapper = new dynamodbMapper.Mapper(myMap);

// create my test data
var myData = {
myStringHashKey: 'my-hash-key-goes-here',
myDateRangeKey: new Date(),
myString: 'my-string-here',
myDate: new Date(),
myNumber: 1234,
myMap: {
myMapString: 'my-map-string-here',
myMapDate: new Date(),
},
myJsonAsString: {
value1: 'first value',
value2: new Date(),
},
myListOfNumbers: [
1234,
5678,
9012,
],
myListOfMaps: [
{
myMapString: 'my-map-string-here-1',
myMapDate: new Date(),
},
{
myMapString: 'my-map-string-here-2',
myMapDate: new Date(),
},
],
myStringSet: [
'abc',
'def',
],
};

// convert javascript object to attribute updates
var attributeUpdates = myMapper.toAttributeUpdates(myData);

// get the key (hash and range)
var key = myMapper.toKey(myData);

// send the updates to dynamodb
dynamodb.updateItem({
Key: key,
TableName: 'mydynamodbtablename',
AttributeUpdates: attributeUpdates,
}, function (updateErr, updateData) {

if (updateErr) {
// do something dramatic because we errored
throw updateErr;
}

// let's fetch our data
return dynamodb.getItem({
Key: key,
TableName: 'mydynamodbtablename',
}, function (getErr, getData) {
if (getErr) {
// do something dramatic because we errored
throw getErr;
}

// convert the DynamoDB item to Javascript Object
var myDataFromAws = myMapper.fromAttributeValues(getData.Item);

// we now have the data converted from attribute values back in javascript object format
});

});

``