Dynamo Helper

README.md

Helper to interact with Dynamo table

Setup

const fields = ['color','price'];
const tableName = "" + projectName + '-widgets-' + stage;
Widget = makeDynamoFuncs(tableName,fields);

Usage

Widget.create({color: 'Green', price: 10}).then(function(widget) {
  // done
});  

Widget.getAll().then(function(widgets) {
  console.log(widgets.length);
});  

makeDynamoFuncs.js

function makeDynamoFuncs(tableName,fields) {
  var res = {}

  res.create = function(attrs) {
    call.id = ""+parseInt(Math.random() * 10000000000000);
    call.createdAt = (new Date()).toString();

    return new Promise(function(resolve, reject) {
      var params = {
        TableName: tableName,
        Item: attrs
      };

      docClient.put(params, function(err, data) {
        if (err) return reject(err);
        return resolve(attrs);
      });
    });
  };

  res.getAll = function() {
    return new Promise(function(resolve, reject) {
      var fs = ['id','createdAt'].concat(fields);
      var params = {
        TableName: tableName,
        AttributesToGet: fs
      };

      docClient.scan(params, function(err, data) {
        if (err) return reject(err);
        return resolve(data["Items"]);
      });

    });
  };

  res.delete = function(key) {
    return new Promise(function(resolve, reject) {
      var params = {
        TableName: tableName,
        Key: {id: key}
      };

      docClient.delete(params, function(err, data) {
        if (err) return reject(err);
        return resolve(data);
      });
    });
  }

  res.deleteAll = function() {
    var me = this;
    return new Promise(function(resolve, reject) {
      me.getAll().then(function(rows) {
        var promises = [];
        rows.forEach(function(row) {
          promises.push(me.delete(row.id));
        });
        Promise.all(promises).then(function() {
          resolve(true);
        }).error(function(err) {
          reject(err);
        });
      });
    });
  }

  return res;
}

// Helper to interact with Dynamo table
// 
// EXAMPLE USAGE
//
// // Setup
// const fields = ['color','price'];
// const tableName = "" + projectName + '-widgets-' + stage;
// Widget = makeDynamoFuncs(tableName,fields);
//
// // Use
// Widget.create({color: 'Green', price: 10}).then(function(widget) {
//   // done
// });  
//
// Widget.getAll().then(function(widgets) {
//   // use widgets
// });