integer()
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|---|---|
| See every accepted call style | Signatures |
| See common and advanced usage | Usage and behavior |
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| Understand reactive constraints | Reactive behavior |
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📐 Signatures
integer
integer(message)
integer(options)
This validator has no configurable constraint value. Its options customize the failure message,
which may itself be reactive, and the reactive when condition.
📖 Usage and behavior
Requires a JavaScript safe integer. It can be passed directly or called with message options:
const myForm = form({
quantity: field(1.5, [integer]),
attempts: field(1.5, [
integer('Enter a whole number.'),
]),
});
It uses Number.isSafeInteger(), rejecting decimals, NaN, infinities, and integers outside JavaScript's exactly representable safe range. null passes. A failure is { kind: 'integer', actual, message }.
💬 Message configuration
Every failure has a default English message. Where supported, pass a string as the final argument or use an options object for a static or reactive message, as shown above.
A message function may read signals. Returning undefined continues through node, Angular
provider, process-wide, and built-in message fallbacks. See
Validator messages.
⚡ Reactive behavior
The options object accepts a reactive when predicate. Signals read from its validator context are
tracked; while it returns false, the rule contributes neither errors nor constraint metadata.
const wholeNumbersOnly = signal(false);
const quantity = field(1.5, [
integer({ when: () => wholeNumbersOnly() })
]);
Reactive constraint functions and message functions track the signals they read. When a resolved constraint becomes unavailable, validators that support optional constraint sources temporarily stop contributing their error and metadata.
The validator runs synchronously as part of its node's validator source. Disabled, readonly, and hidden nodes skip validation until they become interactive again.