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Schema Overview

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@feathersjs/schema provides a way to define data models and to dynamically resolve them. It comes in two main parts:

  • Schema - Uses JSON schema to define a data model with TypeScript types and basic validations. This allows us to:
    • Ensure data is valid and always in the right format
    • Automatically get TypeScript types from schema definitions
    • Automatically generate API documentation
    • Create database adapter models without duplicating the data format
    • Validate query string queries and convert them to the right type
  • Resolvers - Resolve schema properties based on a context (usually the hook context). This can be used for many different things like:
    • Populating associations
    • Securing queries and e.g. limiting requests to a user
    • Removing protected properties for external requests
    • Ability to add read- and write permissions on the property level
    • Hashing passwords and validating dynamic password policies

Here is an example of a user schema definition and resolver:

import { HookContext } from './definitions'
import { schema, resolve, Infer } from '@feathersjs/schema'

export const userSchema = schema({
  $id: 'User',
  type: 'object',
  additionalProperties: false,
  required: ['email', 'password'],
  properties: {
    id: { type: 'number' },
    email: { type: 'string' },
    password: { type: 'string' }
  }
} as const)

export type User = Infer<typeof userSchema>

export const userDataResolver = resolve<User, HookContext>({
  properties: {
    password: async (value) => {
      // Return a hashed version of the password before storing it in the database
      return bcrypt(value)
    }
  }
})

export const userResultResolver = resolve<User, HookContext>({
  properties: {
    password: async (value, _user, context) => {
      // Do not return the password for external requests
      if (context.params.provider) {
        return undefined
      }

      return value
    }
  }
})
import { HookContext } from './definitions'
import { schema, resolve, Infer } from '@feathersjs/schema'

export const userSchema = schema({
  $id: 'User',
  type: 'object',
  additionalProperties: false,
  required: ['email', 'password'],
  properties: {
    id: { type: 'number' },
    email: { type: 'string' },
    password: { type: 'string' }
  }
} as const)

export type User = Infer<typeof userSchema>

export const userDataResolver = resolve<User, HookContext>({
  properties: {
    password: async (value) => {
      // Return a hashed version of the password before storing it in the database
      return bcrypt(value)
    }
  }
})

export const userResultResolver = resolve<User, HookContext>({
  properties: {
    password: async (value, _user, context) => {
      // Do not return the password for external requests
      if (context.params.provider) {
        return undefined
      }

      return value
    }
  }
})

Released under the MIT License.