Pandora Validation

Addon to provide flow and setup functions to validate data using JSON Schema using ajv.

npm install --save @exocet/pandora-validation

Concepts

Labels

Labels allow you to create variations of an entity's representation, they group fields and validations. When you do not specify a label for a field by default the label "default" will be used.

kind: Pandora/entity
metadata:
  namespace: myNamespace
  name: myEntity
spec:
  validations: # Validations applied to entity instance
    default: # Label
      required:
        - name
        - uri
    partial: # Label
      required:
        - id
        - uri
    reference: # Label
      required:
        - id
  fields:
    - name: id
      labels: # This field is present only on "partial" and "reference" schema variations
        - partial
        - reference
    - name: uri
      labels:
        - default
        - partial
    - name: name
      type: string
      labels:
        - default
        - partial
      validation:
        minLength: 1
        maxLength: 80
    - name: description # This field is present only on "default" schema variation
      type: string
      translated: true # Translated Pandora standard
      validation:
        nullable: true # Allow field to be null
        maxLength: 500

Linked entities

Linked entities allow you to create references to structures and / or instances of other entities. They are similar to foreign keys, except that attributes are imported through denormalization. They can be linked references or not, when linked include the fields "id" and "uri", when not linked only import the total or partial structure of another entity.

kind: Pandora/entity
metadata:
  namespace: myNamespace
  name: myForeignEntity
spec:
  fields:
    - name: title
      type: string
    - name: description
      type: string
    - name: tags
      type: array
      validation:
        uniqueItems: true
      items:
        - type: string
          validation:
            maxLength: 20
---
kind: Pandora/entity
metadata:
  namespace: myNamespace
  name: myEntity
spec:
  fields:
    - name: myObjectLinkedReference
      uris: # Allowed URIs
        - myNamespace.myForeignEntity
      reference: myNamespace.myForeignEntity
      linked: true # Linked reference, acts like a foreign key
    - name: myObjectReference
      uris:
        - myNamespace.myForeignEntity
      reference: myNamespace.myForeignEntity
      linked: false # Unlinked reference, only imports the validations
      required: # Cherry-pick the fields from the referenced entity
        - title
    - name: myArrayReference
      type: array
      items:
      uris:
        - myNamespace.myForeignEntity
      reference: myNamespace.myForeignEntity
      linked: false
      required:
        - title
        - tags

Internal fields

Internal fields are ideal for fields that exist outside of a public scope, but are still within the structure of your entity. When you remove unknown properties from a schema normally that field would be removed, to avoid this behavior you can mark the fields as internal.

kind: Pandora/entity
metadata:
  namespace: myNamespace
  name: myEntity
spec:
  fields:
    - name: myInternalField
      type: string
      internal: true

Setup

Available features:

• Generate JSON Schemas from entity definition
• Multiple schemas defined by labels
• Provide validator hook
• Flow step: validation

To add this addon into your project, put the addon spec into your endpoint YAML:

kind: Pandora/endpoint
metadata:
  name: myEndpoint
spec:
  addons:
    - name: validation
      package: "@exocet/pandora-validation"
      flow: true
      setup: true
  configuration:
    validation: # Any configuration here will be passed to ajv configuration
      removeAdditional: true
      allErrors: true

After the setup the following property of the context will be available:

• .application.ajv - The instance of ajv

Hooks

The hooks created by this addon are:

• jsonSchemaValidator (.service.hooks.useHook('jsonSchemaValidator')) - Synchronous hook to validate data against entity schema.

  const [jsonSchemaValidator] = service.hooks.useHook('jsonSchemaValidator');
  const errors = jsonSchemaValidator('myNamespace.myEntity/myLabel', data);
  // errors is null if the data is valid or an array with errors (as strings) if the data is invalid

Flow

The provided flow type and steps are listed bellow:

• validation - This flow validates data:

  kind: Pandora/flowStep
  metadata:
    name: entityValidation
  spec:
    type: validation
    options:
      inboundFrom: request.data # JSON Path to acquire data from execution context
      outboundTo: null # JSON path to put the errors array if invalid
      entity:
        label: default
        namespace: stock
        name: product