{JSON Forms Specification}

A SPECIFICATION FOR BUILDING FORMS IN JSON

🔖 View the Specification

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Overview

When building web based forms, we face many problems including:

• How can we reuse form logic across projects with different backend stacks?
• How can we reuse form logic across projects that use different front end frameworks/technologies?

This specification attempts to bridge the gap between the client and the backend by representing a form using a standard JSON object.

A simple example

• The object below defines a simple (single step) form with a name section, and an email field.
• Nested inside the name section are a first and last name field.
• The form is pre-populated with some initial values.

The consumer of this object is a form builder, which will automatically build a form.

The initial target is a React based form builder, but this spec is platform and framework agnostic.

{
  "version": "0",
  "id": "form-id",
  "initialValues": {
    "name": {
      "first": "Joan",
      "last": "Smith"
    },
    "email": "joan.smith@gmail.com",
  },
  "fields": [
    { 
      "id": "name", 
      "type": "section",
      "data": {
        "title": "Your name",
        "description": "We need to know your name to proceed"
      },
      "fields": [
        { 
          "id": "first", 
          "type": "text",
          "data": {
            "label": "Given name"
          }
        },
        { 
          "id": "name", 
          "type": "text",
          "data": {
            "label": "Surname"
          }
        }
      ]
    },
    { 
      "id": "email",
      "type": "text"
    }
  ]
}

Here is one of many ways a form builder might render the above form:

A more advanced example

Beyond just defining fields and displaying them, this spec supports dynamic form rules, validation and completely custom field types.

• The object below defines an advanced form with a name section, a newsletter signup checkbox, an email field and a custom address typeahead.
• The name section has a title and description
• The first and last name fields have labels
• The email field will only show when the checkbox is ticked. (See form rules)
• The email field has a validation rule with a custom message.
• The address typeahead talks to the endpoint it's provided to suggest addresses to the user as they type.

{
  "version": "0",
  "id": "form-id",
  "fields": [
    { 
      "id": "name", 
      "type": "section",
      "data": {
        "title": "Your name",
        "description": "We need to know your name to proceed"
      },
      "fields": [
        { 
          "id": "first", 
          "type": "text",
          "data": {
            "label": "Given name"
          }
        },
        { 
          "id": "name", 
          "type": "text",
          "data": {
            "label": "Surname"
          }
        }
      ],
    },
    { 
      "id": "signUpForNewsletter",
      "type": "checkbox"
    },
    { 
      "id": "email",
      "type": "text"
      "rules": [
        {
          "action": "show",
          "when": { 
            "eq": ["signUpForNewsletter", true] 
          }
        }
      ],
      "validators": [
        {
          "type": "email",
          "message": "Please enter a valid email address"
        }
      ]
    },
    { 
      "id": "address",
      "type": "address-typeahead"
      "data": {
        "endpoint": "https://address.com"
      }
    }
  ]
}

Here is one of many ways a form builder might render the above form:

Update History

• 17 April 2019: 1.0 Released on Github