Freight Quote

Signals Adapter

Freight Quote

reactiveUmp()

5 rule types

Quote logic mixes predicate requirements, direct field dependencies, mutually exclusive handling branches, admin gating, and promo locks without hand-written orchestration code.

Conditions{ isAdmin: false, promoActive: false }

Conditions

Admin Mode

inactive

OffOn

FREIGHT50 Promo

inactive

OffOn

Shipment

Account Typerequired

enabled

PersonalBusiness

Company Name

disabled

Only business accounts need a company name

Service Levelrequired

enabled

StandardExpressWhite Glove

Vehicle Typerequired

enabled

VanTruckFlatbed

Hazmat

Hazardous

enabled

Shipment contains hazardous materials

Hazmat Class

disabled

Select class...Class 1 — ExplosivesClass 2 — GasesClass 3 — Flammable LiquidsClass 6 — ToxicClass 8 — Corrosive

Enable hazardous materials first

Handling

Handling Mode

enabled

Standard handlingFragileClimate-controlled

Moving Blankets

enabled

Add protective moving blankets

Crate Type

enabled

Select crate...Wood crateFoam-linedCustom build

Temperature Range

enabled

Select range...Frozen (-18°C)Chilled (2-8°C)Ambient (15-25°C)Warm (25-35°C)

Humidity Target

enabled

Select humidity...Low (<30%)Medium (30-60%)High (>60%)

signal state@preact/signals

{
  "conditions": {
    "isAdmin": false,
    "promoActive": false
  },
  "values": {
    "accountType": "personal",
    "serviceLevel": "standard",
    "vehicleType": "van",
    "handlingMode": "none"
  },
  "fouls": []
}

What this demonstrates

A freight quoting form with 13 fields and 7 rules spanning 5 of Umpire’s 6 rule types. The form adapts to user input, external conditions, and mutually exclusive handling modes — all without hand-written orchestration code.

Rule types in play

Rule	What it does here
requires	Company name only matters for business accounts. Hazmat class requires the hazardous toggle.
enabledWhen	Admin-only fields (discount override, price hold) gate on the isAdmin condition. Promo locks service level and vehicle type.
oneOf	Fragile and climate-controlled handling are mutually exclusive branches — picking one hides the other’s fields.
disables	(not used here — see the Printer Menu for disables in action)
conditions	isAdmin and promoActive are external facts, not field values. Toggle them with the switches at the top.

Things to try

1. Switch account type from Personal to Business — Company Name enables. Switch back and Umpire calls a foul on the stale value with an inline reset button.
2. Check “Hazardous materials” — Hazmat Class enables. Uncheck it and the class value produces a foul.
3. Change handling mode from Standard to Fragile — blankets and crate type appear. Switch to Climate-controlled — the fragile fields foul, temp/humidity appear. This is oneOf in action.
4. Toggle the FREIGHT50 promo — Service Level and Vehicle Type disappear (condition-driven hiding).
5. Toggle Admin Mode — Discount Override and Price Hold appear.

Implementation

This demo uses @umpire/signals with Preact and @preact/signals. Each field component reads signal-backed values during render — Preact auto-subscribes and re-renders only the fields that changed.

The entire Umpire integration is the rule definitions and a ~10-line signal adapter. No useEffect, no state synchronization, no manual subscriptions.

const freightUmp = umpire({
  fields,
  rules: [
    requires('companyName', v => v.accountType === 'business'),
    requires('hazClass', 'hazardous'),
    oneOf('handlingMode', {
      fragile: ['blankets', 'crateType'],
      climate: ['tempRange', 'humidity'],
    }, { activeBranch: v => v.handlingMode === 'none' ? null : v.handlingMode }),
    enabledWhen('discountOverride', (_, c) => c.isAdmin),
    enabledWhen('priceHold', (_, c) => c.isAdmin),
    enabledWhen('serviceLevel', (_, c) => !c.promoActive),
    enabledWhen('vehicleType', (_, c) => !c.promoActive),
  ],
})

Seven rules. That’s the entire form logic. Umpire handles the cascading availability, the fouls when stale values need cleanup, and the per-field reason messages.