hemera-arango-store

🥑 Hemera-arango-store package

This is a plugin to use Arangodb with Hemera.

Execute any AQL query from anywhere. For more details ArangoDB Query Language

Start Arangodb with Docker

docker run -e ARANGO_NO_AUTH=1 -d --name arangodb-instance -d arangodb -p 8529:8529

Running the tests

Install and start Arangodb before running the tests.

arangod.conf

endpoint = tcp://127.0.0.1:8529
authentication = false

npm run test

Install

npm i hemera-arango-store --save

Usage

const hemera = new Hemera(nats)
hemera.use(require('hemera-joi'))
hemera.use(require('hemera-arango-store'), {
  database: {
    url: 'http://127.0.0.1:8529',
    name: 'test' // default database
  }
})

Plugin decorators

• hemera.arango
• hemera.aql

API

See Store Interface.

Database specific interface

• Arango API

  • Collection API
    • createCollection
  • Query API
    • executeAqlQuery
  • Transaction API
    • executeTransaction
  • Database API
    • createDatabase

---

createCollection

The pattern is:

• topic: is the store name to publish to arango-store
• cmd: is the command to execute createCollection
• name: the name of the collection string
• database: the database to use against the query. string (optional)
• type: the type of collection to create edge or "" (optional)

Example:

hemera.act(
  {
    topic: 'arango-store',
    cmd: 'createCollection',
    name: 'products'
  },
  function(err, resp) {}
)

---

executeAqlQuery

The pattern is:

• topic: is the store name to publish to arango-store
• cmd: is the command to execute executeAqlQuery
• database: the database to use against the query. string (optional)
• query: the AQL query string
• type: return one or multiple results one or all

Example:

hemera.act(
  {
    topic: 'arango-store',
    cmd: 'executeAqlQuery',
    type: 'one',
    database: 'test',
    query: aql`INSERT ${user} INTO testColl return NEW`
  },
  function(err, resp) {}
)

---

executeTransaction

The pattern is:

• topic: is the store name to publish to arango-store
• cmd: is the command to execute executeTransaction
• database: the database to use against the query. string (optional)
• action: a string evaluating to a JavaScript function to be executed on the server. string
• params: available as variable params when the action function is being executed on server. Check the example below. object
• collection: If collections is an array or string, it will be treated as collections.write. object (optional)
  • read: an array of names (or a single name) of collections that will be read from during the transaction. Array<string> (optional)
  • write: an array of names (or a single name) of collections that will be written from during the transaction. Array<string> (optional)
• lockTimeout: determines how long the database will wait while attemping to gain locks on collections used by the transaction before timing out. integer

Example:

var action = String(function() {
  return true
})
 
hemera.act(
  {
    topic: 'arango-store',
    cmd: 'executeTransaction',
    database: 'test',
    action,
    params: {
      age: 12
    },
    collections: {
      read: 'users'
    }
  },
  function(err, resp) {}
)

---

createDatabase

The pattern is:

• topic: is the store name to publish to arango-store
• cmd: is the command to execute executeAqlQuery
• name: the name of the database. string

Example:

hemera.act(
  {
    topic: 'arango-store',
    cmd: 'createDatabase',
    name: 'test'
  },
  function(err, resp) {}
)