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Computed Fields

Create fields that automatically calculate their value based on formulas using other field values.

Formula Syntax​

Use field paths in your formulas to reference other field values. Basic arithmetic operators (+, -, *, /) are supported.

// Total calculation
price * quantity

// With discount
price * quantity * (1 - discountRate)

// String concatenation
firstName + " " + lastName

Output Types​

When creating a computed field, specify the output type:

  • Number - For mathematical calculations
  • String - For text concatenation
  • Boolean - For true/false results

Examples​

Price Calculation​

// Subtotal
unitPrice * quantity

// With tax
unitPrice * quantity * 1.08

// With discount and tax
unitPrice * quantity * (1 - discount) * (1 + taxRate)

String Operations​

// Full name
firstName + " " + lastName

// Full address
street + ", " + city + ", " + state + " " + zipCode

Boolean Logic​

// Check if over limit
total > 1000

// Check if complete
firstName && lastName && email

Creating a Computed Field​

  1. Add a Computed field type to your form
  2. Set the Label for display
  3. Enter the Formula using field references
  4. Select the Output Type (number, string, boolean)
  5. Configure Display Options (decimal places, format)

Available Functions​

Math Functions​

  • Basic arithmetic: +, -, *, /
  • Modulo: %
  • Parentheses for order of operations

String Functions​

  • Concatenation with +
  • Template literals with field references

Comparison Operators​

  • ==, != - Equality
  • >, <, >=, <= - Comparisons
  • &&, || - Logical AND/OR

Field References​

Reference other fields by their path:

// Simple field
fieldName

// Nested field
address.city

// Array field (first item)
items[0].price
warning

Computed fields are read-only and recalculate automatically when their dependencies change.

Display Configuration​

Number Formatting​

  • Decimal Places - Number of decimals to show
  • Currency Format - Display as currency
  • Percentage - Display as percentage

Visibility​

  • Show in Form - Display to users
  • Hidden - Calculate but don't show
  • Read-only - Always true for computed fields

Use Cases​

  • Order Totals - Sum line items, apply discounts
  • Full Names - Combine first and last names
  • Age Calculation - Calculate from birth date
  • Progress Percentage - Calculate completion
  • Running Totals - Cumulative calculations

Best Practices​

  1. Keep formulas simple - Break complex calculations into steps
  2. Handle edge cases - Consider null/undefined values
  3. Test thoroughly - Verify calculations with different inputs
  4. Document formulas - Add help text explaining the calculation
  5. Consider performance - Complex formulas may slow the form

Troubleshooting​

Field showing NaN:

  • Check that referenced fields have numeric values
  • Verify field paths are correct

Calculation not updating:

  • Ensure dependency fields are correctly referenced
  • Check for circular dependencies

Wrong result:

  • Verify order of operations
  • Test with known values

Next Steps​