Getting started with Elasticmagic

Elasticmagic is a Elasticsearch query builder and ORM for JavaScript/Typescript.

It helps you easily build queries which are typed and safe.

You do not need to remember how to write json DSL for Elasticsearch, Elasticmagic will do it for you.

Installation

To install Elasticmagic via NPM:

npm install --save elasticmagic

Also you need an Elasticseach official js client

npm install --save @elastic/elasticsearch

Basic example

import { Client } from '@elastic/elasticsearch';
import { 
  Cluster,
  Field,
  IntegerType,
  Doc,
  Bool,
} from "elasticmagic-js";
/**
 * Here we creating our document which maps structure of same document in Elasticsearch.  
 * 
 * We will use this class as our query builder.
 * Also when we will get result from elasticsearch, we instantiate this class
 * and populate it with data from Elasticsearch hits.
 * 
 * First we declare docType - it must be the same as document in Elasticsearch mapping. 
 * 
 * Then we declare static fields that will be user to build our queries. 
 * As we do not need an instance of this class to build queries, the fields are static.
 * 
 * Next, conventionaly, we declare instance properties, as you can see, with almost same name. 
 * Then lettercase is same as fields in Elasticseach mapping
 * 
 * And thats is.  
 */
class OrderDoc extends Doc {
  public static docType: string = 'order';
  public static userId = new Field(IntegerType, 'user_id', OrderDoc);
  public user_id?: number;
  public static status = new Field(IntegerType, 'status', OrderDoc);
  public status?: number;
  public static source = new Field(IntegerType, 'source', OrderDoc);
  public source?: number;
  public static price = new Field(IntegerType, 'price', OrderDoc);
  public price?: number;
  public static dateCreated = new Field(DateType, 'date_created', OrderDoc);
  public date_created?: Date;
}
// Create a Elasticsearch client which will be passed to cluster.
const client = new Client({ node: 'http://es6-test:9200' });
// Create cluster instance. Its an entrypiint for interacting with Elasticsearch.
const cluster = new Cluster(client, 'test_order_index');
// Lets start building our query.
// Calling searchQuery method we start creating new query.
// We using builder pattern, so you can chain any amount of methods
const query = cluster.searchQuery({ routing: 1 })
  .source(true)
  .filter(
    Bool.must(
      OrderDoc.userId.in([1]),
      OrderDoc.status.in([1, 2]),
      OrderDoc.source.not(1),
      OrderDoc.dateCreated.lte(new Date().toISOString())
    )
  );
// To make a query to Elasticsearch we calling getResult.
const result = await query.getResult<OrderDoc>();
console.log(result.getIds()); // prints ["1"]
const hit = result.hits[0];
console.log(hit.user_id); // prints 1

We can check what query Elasticmagic will build for us.

console.log(query.toJSON()) 
// to see prettified query
console.log(query.toPrettyJSON());