compareBy Method

Sets a custom comparison strategy that will be used to determine if the state has changed. This comparison can be one of the predefined comparison types ('equals' or 'strict') or a custom comparison function

@param comparison: Comparison
The comparison method to use for evaluating state changes

@returns this
The instance of the state, allowing for method chaining

API


compareBy(comparison: Comparison): this;

Example


import {changeDefaultComparison} from '@bitfiber/rx';
import {signalState} from '@bitfiber/ng/rx';
 
const data1 = signalState<number>(10, s => s
  // Uses the `equals` function from the package '@bitfiber/utils' for comparing values
  // this comparison is by default
  .compareBy('equals'));
 
const data2 = signalState<number>(10, s => s
  // Uses '===' for comparing values
  .compareBy('strict'));
 
const data3 = signalState<number | string>(10, s => s
  // Uses a custom function for comparing values
  .compareBy((a, b) => Number(a) === Number(b)));
 
// By default, uses the `equals` function for comparing values.
// To set a different comparison type for all states by default, use this function
changeDefaultComparison('strict');