Methods

init

Initialize the DynamoDB object.

db:init( config )

Config Properties

Name	Description	Type
aws_key	User AWS access key.	String
aws_secret	User AWS secret key.	String
aws_region	AWS region for DynamoDB.	String
debug	Output response data structure.	Boolean

Example

local db = require("dynamodb.client")

db:init({
  aws_key = auth.key,
  aws_secret = auth.secret,
  aws_region = "us-east-1",
  debug = true
})

---

request

Make a request to the DynamoDB service.

db:request(action, payload)

Request Properties

Name	Description	Type
action	The DynamoDB action to perform.	String
payload	The required payload for the action.	Table

See Actions for more details on action types.

See Examples for more details on payload types.

---

events

To capture the request response data, you must register an event listener on the events property.

DynamoDBEvent

--set up listener function
local function dynamoDBResponse( evt )
  if evt.error then
    print(evt.reason, evt.status)
  else
    --response as table data
    local data_table = evt.result --Table

    --response as JSON string
    print(evt.response) --JSON
  end
end

--add event listener
db.events:addEventListener("DynamoDBEvent", dynamoDBResponse)

--make request
db:request("ListTables", {Limit=5})

Event Properties

The "DynamoDBEvent" will fire when data from the service is returned. The event can contain the following properties.

error

If the error propery is set, an error of some type has occurred. You can view the reason, and status code using the event properties:

local function dbListener( evt )
  if evt.error then
    --reason
    print(evt.reason)
    --status code
    print(evt.status)
  end
end

...

result

If no error has occured then you can retreive the data table through the result property:

local function dbListener( evt )
  if not evt.error then
    --result table
    print(evt.result.some_key_path)
  end
end

---

Attribute Type Methods

DynamoDB attribute values require an attribute type. While you can manually create each value entry, these methods offer another approach, as well as, make sure the encoding is properly handled.

For more details on attributes data see DynamoDB AttributeValue.

S

Returns a formatted string value as an attribute value.

local str = db:S("A string value")

N

Returns a formatted number value an attribute value.

local num = db:N(12)

B

Returns encoded binary data as an attribute value.

local bin = db:B(<binary-data>)

M

Returns a map value as an attribute value.

local map = db:M({
  Artist = db:S("The Acme Band"),
  Rating = db:N(10),
  Genre = db:L(db:S("Pop"), db:S("Upbeat"))
})

L

Returns a list value as an attribute value.

local list = db:L({
  db:S("Hello"),
  db:N(25),
  db:BOOL(false),
  db:M({Age=db:N(25), Name=db:S("John")})
})

SS

Returns a string set as an attribute value.

local string_set = db:SS({
  db:S("Hello"),
  db:S("World")
})

NS

Returns a number set as an attribute value.

local num_set = db:NS({
  db:N(12),
  db:N(34),
  db:N(2.34)
})

BS

Returns a binary set as an attribute value.

local bin_set = db:BS({
  db:B(<binary-data>),
  db:B(<binary-data>)
})

BOOL

Returns a boolean value as an attribute value.

local bool = db:BOOL(false)

NULL

Returns a null value type as an attribute value.

local null = db:NULL()