fields.md

title	Field Registry

Object UI uses a Field Registry system to decouple the core engine from specific UI implementations of fields. This allows for rich extensibility and plugin support.

Concept

The @object-ui/fields package serves as the "Universal Language" for rendering values.

When a component like <ObjectGrid> needs to render a date field, it doesn't import a DatePicker directly. Instead, it asks the registry:

"Hey, give me the component responsible for rendering type 'date'."

This architecture allows you to:

1. Override standard fields (e.g. replace the native date picker with a fancy one).
2. Add new field types (e.g. add a rating or signature field).
3. Keep bundles small (heavy components like Code Editors are loaded only if their plugin is registered).

Usage

1. Registering a Custom Field

You can register a custom renderer globally, typically at your app's entry point.

// src/setup.tsx
import { registerFieldRenderer, type CellRendererProps } from '@object-ui/fields';

const MyRatingField = ({ value, onChange }: CellRendererProps) => {
  return (
    <div className="rating">
      {[1, 2, 3, 4, 5].map(star => (
        <span 
          key={star} 
          onClick={() => onChange(star)}
          style={{ color: star <= value ? 'gold' : 'grey' }}
        >
          ★
        </span>
      ))}
    </div>
  );
};

// Register it
registerFieldRenderer('rating', MyRatingField);

2. Using in Schema

Once registered, you can simply use the new type in your JSON schema.

{
  "type": "form",
  "fields": [
    {
      "name": "customer_satisfaction",
      "type": "rating", 
      "label": "Satisfaction"
    }
  ]
}

Standard Fields

Object UI comes with built-in support for the standard ObjectStack Protocol types:

Type	Description
text	Single line text
textarea	Multi-line text
number	Numeric input
currency	Currency formatting
percent	Percentage values
date	Date picker
datetime	Date & Time picker
boolean	Checkbox / Switch
select	Dropdown
lookup	Reference to another object
master_detail	Parent-child relationship
user	Person picker — searches the sys_user object (a lookup specialized to users)
owner	Record owner — a user field, typically read-only and stamped with the current user

Using Renderers in Custom Components

If you are building your own custom component (like a Kanban board card), you can leverage the registry to render fields without reinventing the wheel.

import { getCellRenderer } from '@object-ui/fields';

export const KanbanCard = ({ task }) => {
  // Get the standard renderer for a 'user' type field
  const UserRenderer = getCellRenderer('user');
  
  return (
    <div className="card">
      <h3>{task.name}</h3>
      <div className="assignee">
        <UserRenderer 
          value={task.assignee} 
          field={{ type: 'user' }} 
        />
      </div>
    </div>
  );
};