some

import { some } from 'patronum';
// or
import { some } from 'patronum/some';

some({ predicate: Function, stores })

Motivation

Method calculates boolean value if at least one state of the store satisfies the condition in predicate. It is useful to check that user filled at least a single field.

Formulae

$result = some({ predicate: (value) => true, stores });

• read it as: has some predicate at least one store
• $result will be true if each at least predicate on each store value from values returns true, otherwise it will be false

Arguments

1. predicate ((value: T) => boolean) — Function to check store value
2. stores (Array<Store<T>>) — List of stores

Return

• $result (Store<boolean>) — true if at least one store corresponds to predicate

Example

const $width = createStore(440);
const $height = createStore(820);

const $tooBig = some({
  predicate: (size) => size > 800,
  stores: [$width, $height],
});

console.assert(true === $tooBig.getState());

some({ predicate: value, stores })

Motivation

This overload compares each store to specific value in predicate. It is useful when you write combine with || very often, for example to create an invalid form flag.

Formulae

$result = some({ predicate: value, stores });

• $result will be true if at least one value in stores equals value, otherwise it will be false

Arguments

1. predicate (T) — Data to compare stores values with
2. stores (Array<Store<T>>) — List of stores to compare with value
3. type of predicate and stores should should be the same

Return

• $result (Store<boolean>) — true if at least one store contains value

Example

const $isPasswordCorrect = createStore(true);
const $isEmailCorrect = createStore(true);

const $isFormFailed = some({
  predicate: false,
  stores: [$isPasswordCorrect, $isEmailCorrect],
});

console.assert(false === $isFormFailed.getState());

some({ predicate: Store, stores })

since

patronum 1.8.0

Motivation

This overload compares each store to specific value in store predicate. It is useful when you write combine with || very often, for example to create an invalid form flag.

Formulae

$result = some({ predicate: $value, stores });

• $result will be true if at least one value in stores equals value in $value, otherwise it will be false

Arguments

1. predicate (Store<T>) — Store contains value to compare values from stores with
2. stores (Array<Store<T>>) — List of stores to compare with value
3. type of value and stores should be the same

Return

• $result (Store<boolean>) — true if at least one store contains value

Example

const $allowToCompare = createStore(true);

const $isPasswordCorrect = createStore(true);
const $isEmailCorrect = createStore(true);

const $isFormFailed = some({
  predicate: $allowToCompare,
  stores: [$isPasswordCorrect, $isEmailCorrect],
});

console.assert(false === $isFormFailed.getState());

Shorthands

$result = some(stores, value);
$result = some(stores, (value) => false);
$result = some(stores, $predicate);

Shorthand have the same rules as the main overrides, just it uses positional arguments instead of object-form.

Arguments

1. stores (Array<Store<T>>) — List of stores to compare with predicate in the second argument
2. predicate (Store<T> | (value: T) => boolean | T) — Predicate to compare with