dynamo-processor

DynamoDB processor operates a process by simple JSON expression.

Features

• If it have failed to set child objects to Map Type field, auto trying to update with initial fields again. futhermore, If it have failed by the conflict, auto trying the updating process at first once more.
• Node.js 12 or later
• AWS SDK for JavaScript v3

Click here for the version that supports AWS SDK v2

Install

$ npm install -save @aws-sdk/client-dynamodb @aws-sdk/lib-dynamodb @aws-sdk/util-dynamodb
$ npm install -save dynamo-processor

How to Use

const DynamoProcessor = require('dynamo-processor')
const dp = new DynamoProcessor({ region: 'ap-northeast-1' });

new DynamoProcessor(options)

• options <Object> DynamoDBClientConfig as well
  • wrapFunc <Boolean> If this is true, proc method returns a Function that wraps the Promise in case that promise evaluation need lazy. (default is false)

Methods

• proc method is to analyze an item and to process the item by the action
• get, put, update, delete, batchWrite, batchDelete methods as shortcut for each action

getItem

proc({ action: 'get', table, key })

dp.proc({
  table: 'users',
  action: 'get', // optional
  key: {
    id: 1
  }
})
.then((item) => {
  console.log(item); // { name: 'Taro', id: 1, age: 16 }
});

get(key)

dp.get('users', { id: 1 });

batchGetItem

proc({ action: 'get', table, keys })

dp.proc({
  table: 'users',
  action: 'get', // optional
  keys: [
    { id: 1 },
    { id: 2 }
  ]
})
.then((items) => {
  console.log(items[0]); // { id: 1, ... }
  console.log(items[1]); // { id: 2, ... }
});

putItem

dp.proc({
  table: 'users',
  action: 'put', // optional
  item: {
    id: 2,
    name: 'Michael',
    age: 25,
    address: {
      prefecture: 'Osaka'
    }
  }
})
.then((item) => {
  console.log(item);
  // { name: 'Michael',
  //   id: 2,
  //   address: { prefecture: 'Osaka' },
  //   age: 25 }
});

put(table, item)

dp.put('users', {
  id: 2,
  name: 'Michael',
  age: 25,
  address: {
    prefecture: 'Osaka'
  }
});

batchWriteItem (PutRequest)

proc({ action: 'put', table, items })

dp.proc({
  table: 'users',
  action: 'put', // optional
  items: [
    { id: 2, name: 'Michael' },
    { id: 3, name: 'Cindy' }
  ]
})
.then(unprocessedItems => {
  console.log(unprocessedItems); // undefined shows all success
});

batchWrite(table, items)

dp.batchWrite('users', [
  { id: 2, name: 'Michael' },
  { id: 3, name: 'Cindy' }
]);

updateItem

SET

The space in a key is instead of the separator (.) between parent and child because a space is rarely used for a variable name.

dp.proc({
  table: 'users',
  action: 'update', // optional
  key: {
    id: 3
  },
  set: {
    name: 'Taro',
    age: 14,
    'address prefecture': 'Tokyo'
  }
})
.then((item) => {
  console.log(item);
  // { name: 'Taro',
  //   id: 3,
  //   address: { prefecture: 'Tokyo' },
  //   age: 14 }
});

ADD

dp.proc({
  table: 'users',
  action: 'update', // optional
  key: {
    id: 3
  },
  add: {
    age: 1
  }
})
.then((item) => {
  console.log(item);
  // { name: 'Taro',
  //   id: 3,
  //   address: { prefecture: 'Tokyo' },
  //   age: 15 }  age was incremented
});

ADD to set

pushset is adding to NumberSet or StringSet or BinarySet.

dp.proc({
  table: 'users',
  action: 'update', // optional
  key: {
    id: 4
  },
  pushset: {
    cards: 30
  }
})
.then((item) => {
  console.log(item);
});

REMOVE

dp.proc({
  table: 'users',
  action: 'update', // optional
  key: {
    id: 3
  },
  remove: [
    'age',
    'address prefecture'
  ]
})
.then((item) => {
  console.log(item);
  // { name: 'Taro',
  //   id: 3,
  //   address: {} }  age and address.prefecture was removed
});

DELETE from set

delete is removing from NumberSet or StringSet or BinarySet.

dp.proc({
  table: 'users',
  action: 'update', // optional
  key: {
    id: 4
  },
  delete: {
    cards: 20
  }
})
.then((item) => {
  console.log(item);
});

update(table, keys, ope, [initFields])

dp.update('users', {
    id: 4
  },
  {
    set: { name: 'foo' }
  }
})
.then((item) => {
  console.log(item);
});

deleteItem

proc({ action: 'delete', table, key })

dp.proc({
  table: 'users',
  action: 'delete',
  key: {
    id: 1
  }
})
.then((item) => {
  console.log(item); // null
});

delete(table, keys)

dp.delete('users', { id: 1 });

batchWriteItem (DeleteRequest)

proc({ action: 'delete', table, keys })

dp.proc({
  table: 'users',
  action: 'delete',
  keys: [
    { id: 2 },
    { id: 3 }
  ]
})
.then(unprocessedItemKeys => {
  console.log(unprocessedItemKeys); // undefined shows all success
});

batchDelete(table, keys)

dp.batchDelete('users',[
  { id: 2 },
  { id: 3 }
])

Multiple items

getItems as Promise Array

Promise.all(
  dp.proc({
    table: 'users',
    action: 'get', // optional
    keys: [
      { id: 1 },
      { id: 2 }
    ]
  }, { useBatch: false })
)
.then((items) => {
  console.log(items[0]); // { id: 1, ... }
  console.log(items[1]); // { id: 2, ... }
});

putItems as Promise Array

Promise.all(
  dp.proc({
    table: 'users',
    action: 'put', // optional
    items: [
      { id: 1, val: 'foo' },
      { id: 2, val: 'bar' }
    ]
  }, { useBatch: false })
)
.then((items) => {
  console.log(items[0]); // { id: 1, ... }
  console.log(items[1]); // { id: 2, ... }
});

deleteItems as Promise Array

Promise.all(
  dp.proc({
    table: 'users',
    action: 'delete',
    keys: [
      { id: 1 },
      { id: 2 }
    ]
  }, { useBatch: false })
)
.then(results => {
  console.log(results[0]); // null
  console.log(results[1]); // null
});

createTable

dp.createTable('producthistories', {
    productId: 'S', // HASH key
    version: 'N'    // RANGE key
  },
  { // options
    readCU: 20, // default 5
    writeCU: 3   // default 5
  })
.then(() => {
  console.log('Succeeded to create table')
});

If first argument is object, it passes through as raw params. In short, dp.createTable(params) equals dynamodb.createTable(params).promise().

deleteTable

dp.deleteTable('producthistories')
.then(() => {
  console.log('Delete to create table')
});

LICENSE

MIT