npm:@commodo/hooks

README

Commodo is a library of higher order functions (HOFs) that let you create and compose rich data models.

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Quick example

A simple model

The following example shows how to create a simple data model, which you can later use to validate data (e.g. data received as body of an HTTP request):

import { withFields, string, number, boolean } from "@commodo/fields";

const Animal = withFields({
    name: string({
        validation: value => {
            if (!value) {
                throw Error("A pet must have a name!");
            }
        }
    }),
    age: number(),
    isAwesome: boolean(),
    about: fields({
        value: {},
        instanceOf: withFields({
            type: string({ value: "cat" }),
            dangerous: boolean({ value: true })
        })()
    })
})();

const animal = new Animal();
animal.populate({ age: "7" }); // Throws data type error, cannot populate a string with number.

animal.populate({ age: 7 });
await animal.validate(); // Throws a validation error - name must be defined.

animal.name = "Garfield";
await animal.validate(); // All good.

More complex model

Using other HOFs, you can create more complex models, that have a name, attached hooks, and even storage layer, so that you can easily save the data to the database:

import { withFields, string, number, boolean, fields, onSet } from "@commodo/fields";
import { withName } from "@commodo/name";
import { withHooks } from "@commodo/hooks";
import { withStorage } from "@commodo/fields-storage";
import { MongoDbDriver, withId } from "@commodo/fields-storage-mongodb";
import { compose } from "ramda";

// Define User and Verification models.
const Verification = compose(
  withFields({
    verified: boolean(),
    verifiedOn: string()
  })
)();

const User = compose(
  withFields({
    firstName: string(),
    lastName: string(),
    email: compose(
      onSet(value => value.toLowerCase())
    )(string()),
    age: number(),
    scores: number({ list: true }),
    enabled: boolean({ value: false }),
    verification: fields({ instanceOf: Verification })
  }),
  withHooks({
    async beforeCreate() {
      if (await User.count({ query: { email: this.email } })) {
        throw Error("User with same e-mail already exists.");
      }
    }
  }),
  withName("User"), // Utilized by storage layer, to determine collection / table name.
  withId(),
  withStorage({
    driver: new MongoDbDriver({ database })
  })
)();

const user = new User();
user.populate({
  firstName: "Adrian",
  lastName: "Smith",
  email: "aDrIan@google.com",
  enabled: true,
  scores: [34, 66, 99],
  verification: {
    verified: true,
    verifiedOn: "2019-01-01"
  }
});

await user.save();

Is Commodo an ORM/ODM?

Fundamentally, Commodo is not an ORM/ODM, but can very quickly become one, by utilizing an additional HOF. You can use the already provided @commodo/fields-storage or even create your own if you don't like the existing one.

Using HOFs is a very flexible approach for defining your data models, because you can append only the functionality you actually need and will use.

Core packages:

The following section shows all of the useful higher order functions that you can use right now.

Package	Short Description	Version
@commodo/fields	The starting point of every model. Provides base `string`, `number`, `boolean` and `model` fields.
@commodo/name	Assign a name to your models.
@commodo/hooks	Provides methods for defining and triggering hooks on your models.
@commodo/fields-storage	Enables saving models to a database (with an appropriate driver, e.g. MySQL).

Additional packages:

Package	Short Description	Version
@commodo/fields-storage-ref	Provides `ref` field, for saving references to other models saved in database.
@commodo/fields-storage-mongodb	A MongoDB driver for @commodo/fields-storage package.
@commodo/fields-storage-soft-delete	Introduces deleted boolean field to mark whether a model was deleted or not, instead of physically deleting the entry in the storage.

Community packages:

Package	Short Description	Version
commodo-fields-date	Provides `date` field, for saving dates.
commodo-fields-object	Provides `object` field, for saving plain objects.
commodo-fields-int	Provides `int` field, for saving integer numbers.
commodo-fields-float	Provides `float` field, for saving float numbers.
commodo-fields-storage-crud-logs	Adds and automatically manages `createdOn`, `updatedOn`, `savedOn` fields.