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Custom Field Validation

Custom field definitions support rule-based validation with custom error messages. Rules are enforced in the UI (CrudForm) and revalidated on the server in APIs handling custom user entities.

Supported rules:

  • required: value must be present (non-empty string/array, true for checkboxes)
  • date: parseable date string
  • integer: number is an integer
  • float: number is finite
  • lt/lte/gt/gte: numerical comparisons (requires param number)
  • eq/ne: strict equality/inequality compared to param
  • regex: value matches provided regex pattern string

Definition syntax (configJson.validation):

validation: [
  { rule: 'required', message: 'Required' },
  { rule: 'integer', message: 'Must be integer' },
  { rule: 'gte', param: 1, message: '>= 1' },
  { rule: 'lte', param: 5, message: '<= 5' },
  { rule: 'regex', param: '^[a-z0-9_-]+$', message: 'Invalid slug' },
]

UI behavior:

  • CrudForm reads definitions for entityId, displays an asterisk when a required rule is present, and validates client-side before submitting.

Server behavior:

  • The Entities records API validates custom field values via shared logic before persisting, returning { error: 'Validation failed', fields: { cf_<key>: 'Message' } } with 400 on errors.

Shared helper:

  • packages/shared/src/modules/entities/validation.ts exports validateValuesAgainstDefs(values, defs) to evaluate rules.