batch.js

function Batch(tableName) {
	this.tableName = tableName;
	this.putRequests = [];
}

Batch.prototype.addRow = function(row) {
	var item = {};

	// See http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/DynamoDB.html#batchWriteItem-property

	// Example "Item" JSON:
	//
	// "Item": {
	//   "column1": {
	//     "S": "foo"
	//   },
	//   "column2": {
	//     "S": "bar"
	//   }
	// }

	// Right now, we only support string values.

	for (var column in row) {
		var value = row[column];

		if (value && value.length > 0) {
			item[column] = { "S": value };
		}
	}

	var request = {
		"PutRequest": {
			"Item": item
		}
	};

	this.putRequests.push(request);
}

Batch.prototype.getLength = function() {
	return this.putRequests.length;
}

Batch.prototype.getBatchWriteItemParams = function() {
	var tableRequests = {};
	tableRequests[this.tableName] = this.putRequests;

	var params = {
		"RequestItems": tableRequests
	};

	return params;
}

module.exports = Batch;