nomatic-data

Extensible Object-relational Mapping Framework for Node.js

Overview

Written in TypeScript, this package uses Active Record, Data Mapper, and Adapter patterns to create an Object-Relational Mapping (ORM) tool that provides flexibility and extensibility.

Adapters allow you to connect to a variety of data sources. You can use a pre-built Adapter (see table below), or you can write your own by implementing either the Adapter or DatabaseAdapter abstract classes.

Each Adapter is operated by one or more Mapper instances. Each Mapper instance is managed by a Container instance. A Mapper will generate Record instances, which store the state of each document in the collection.

Installation

You can install from npm by doing:

npm i --save nomatic-data

If you want to write your own adapter, you can stop there. Otherwise, you'll need to install an adapter:

Adapter	Author	Links	Installation
ArangoDB	bdfoster	npm, GitHub	npm i --save nomatic-arangodb-adapter

Example

This example uses the ArangoDB adapter.

import { Container } from 'nomatic-data';
import ArangoDBAdapter from 'nomatic-arangodb-adapter';

const adapter = new ArangoDBAdapter({
    name: 'my-database',
    host: '127.0.0.1',
    port: 8579,
    password: 'somethingMoreSecureThanThis'
});

const store = new Container({
    adapter: adapter,
    
    /**
     * A few hooks are provided for your convenience, including:
     * - beforeGet
     * - afterGet
     * - beforeInsert
     * - afterInsert
     * - beforeUpdate
     * - afterUpdate
     * - beforeValidate
     * - afterValidate
     */ 
    beforeInsert(mapper, record) {
        record.createdAt = new Date();
    },
    beforeUpdate(mapper, record) {
        record.updatedAt = new Date();
    },
    
    /**
     * Here, we define the schema of all of our mappers. Other options
     * for each mapper can also be set here. Schema validation is provided
     * by [ajv](https://github.com/epoberezkin/ajv).
     */
    mappers: {
        people: {
            properties: {
                /**
                 * Implicit properties, such as `id` and `rev`, need not be 
                 * defined here. 
                 */ 
                firstName: {
                    type: 'string'
                },
                lastName: {
                    type: 'string'
                },
                emailAddress: {
                    type: 'string',
                    format: 'email'
                }
            },
            required: ['firstName', 'lastName'],
            /**
             * By default, additional properties are allowed in the record.
             */
            additionalProperties: false
        },
        accounts: {
            properties: {
                people: {
                    type: 'array',
                    items: {
                        type: 'string',
                        /**
                         * The 'mapper' keyword enforces relational integrity. Each item
                         * in this array matches an `id` of a record in the collection
                         * managed by the 'people' mapper.
                         */ 
                        mapper: 'people'
                    },
                    default: []
                }
            }
        }
    }
});

/**
 * The `load()` method will establish a connection with the database server, 
 * ensure that the database exists (or it will try and create it), and 
 * ensure all collection exists (or will create them).
 */
store.load().then(() => {
    return store.insertAll('people', [
        { firstName: 'John', lastName: 'Doe' },
        { firstName: 'Jane', lastName: 'Doe' }
    ]);
}).then(() => {
    /**
     * This is one way you can query for documents.
     */
    store.find('people')
        .where('lastName')
        .eq('Doe')
        .sort('firstName', 1)
        .limit(2)
        .skip(1)
        .run().then((results) => {
        //...
    });
    
    /**
     * You can also query much like how MongoDB query filters. The supported operators are:
     *  - $and
     *      Syntax: { $where: { $and: [ <expression>, ..., <expression> }, ... }
     *  - $or
     *      Syntax: { $where: { $or: [ <expression>, ..., <expression> }, ... }
     *  - $eq (expression)
     *      Syntax: { <property>: { $eq: { <value> } }
     *  - $ne (expression)
     *      Syntax: { <property>: { $ne: { <value> } }
     *  - $gt (expression)
     *      Syntax: { <property>: { $gt: { <value> } }
     *  - $gte (expression)
     *      Syntax: { <property>: { $gte: { <value> } }
     *  - $lt (expression)
     *      Syntax: { <property>: { $lt: { <value> } }
     *  - $lte (expression)
     *      Syntax: { <property>: { $lte: { <value> } }
     *  - $in (expression)
     *      Syntax: { <property>: { $in: [ <value>, ..., <value> ] }
     *  - $nin (expression)
     *      Syntax: { <property>: { $nin: [ <value>, ..., <value> ] }
     *  - $exists (expression)
     *      Syntax: { <property>: { $exists: <true | false> } }
     * 
     * An expression always follows this form: 
     *  { <property>: { <operator>: <value> | [ <value>, ..., <value>] }
     *  
     * All the operators above can only be used in a $where object. 
     */
    store.findAll('people', {
        $where: {
            firstName: 'Jane'
        },
        $sort: [
            ['firstName', 1]
        ],
        $limit: 2,
        $skip: 1
    }).then((results) => {
        //...
    });
});

The API documentation (generated by TypeDoc) can be found here.

More documentation will be added as moves forward, but if you have a question please feel free to open an issue.