StringSignal

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ReactiveModule Overview

StringSignal

Monitors a string value.

Example

//============================================================================
// Performs various operations with a given StringSignal.
//
//
// Required project capabilities:
// - Locale (auto added on module import)
//
//============================================================================

// Load in the required modules
const Locale = require('Locale');
const Diagnostics = require('Diagnostics');

// Get the device's language and region
const language = Locale.language;
const region = Locale.region;

//==========================================================================
// Compare the value of a StringSignal to a given string
//==========================================================================

// Compare whether the device region matches the ISO 3166-1 code for
// the 'US' region
const regionIsUs = region.eq("US");

if (regionIsUs){
  Diagnostics.log("Device region is US");
} else{
  Diagnostics.log("Device region is not US");
}


//==========================================================================
// Monitor changes to a StringSignal's value
//==========================================================================

// Monitor changes to the value of the 'language' signal
language.monitor({fireOnInitialValue: false}).subscribe((event) => {

  // Log the device language to the console
  Diagnostics.log(`Device language is: ${event.newValue}`);

  // Old values of a given StringSignal can also be accessed
  // Diagnostics.log(`Previous value: ${event.oldValue}`);
});

Properties

This module exposes no properties.

Methods

Method	Description
`concat`	concat(other: StringSignal \| string): StringSignal Returns a `StringSignal` containing the concatenation of the values specified by the input signals. See Also: `ReactiveModule.concat` * `other` - the `StringSignal` or string to concatenate with.
`contains`	contains(searchFor: StringSignal \| string): BoolSignal If the value contains the value of `searchFor` then `true` is returned. If not, then `false` is returned.
`delayBy`	delayBy(timeSpan: {milliseconds: number}): ISignal Delays a signal. The argument is an object with a "milliseconds" property specifying the delay duration in milliseconds.
`eq`	eq(other: StringSignal \| string): BoolSignal Compares whether the signal's value is equal to the value of the `StringSignal` passed in the argument and returns the result as a `BoolSignal`. If the value is equal to the value of `other` then `true` is returned. If not, then `false` is returned. The `Reactive.eq()` method provides equivalent functionality. * `other` - the `StringSignal` or string to compare against.
`history`	history(framesCount: number, initialValues?: Array<string>): SignalHistory<string> Returns a `SignalHistory` object containing the values of the signal from past frames. Historical signal values are initialized with the signal's value at the time the method was called, or with `initialValues` if provided. * `framesCount` - the number of previous frames to track. * `initialValues` - optional initial values for the signal.
`monitor`	monitor(config?: {fireOnInitialValue?: false \| true}): EventSource<{newValue: string, oldValue: string}> Returns an `EventSource` that emits an event whenever the value of the `StringSignal` changes. The event contains a JSON object which provides the old and new values of the signal in the format `{ "oldValue": number, "newValue": number }`. // Load in the required modules const Locale = require('Locale'); const Diagnostics = require('Diagnostics'); // Get the device's language const language = Locale.language; // Monitor changes to the value of the 'language' signal language.monitor({fireOnInitialValue: false}).subscribe((event) => { // Log the device language to the console Diagnostics.log(`My language is: ${event.newValue}`); // Old values of a given StringSignal can also be accessed // Diagnostics.log(`Previous value: ${event.oldValue}`); }); * `config` - an optional configuration for the event source. The `config` JSON object can have the following field: `fireOnInitialValue` - specifies whether an initial event should be emitted containing the signal's initial value. If no value is specified, `false` is used by default. If set to `true`, an initial event will be emitted but `oldValue` will not be available for the first instance.
`ne`	ne(other: StringSignal \| string): BoolSignal Compares whether the signal's value is not equal to the value of the `StringSignal` passed in the argument and returns the result as a `BoolSignal`. If the value is not equal to the value of `other` then `true` is returned. If the values are equal then `false` is returned. The `Reactive.ne()` method provides equivalent functionality. * `other` - the `StringSignal` or string to compare against.
`pin`	pin(): StringSignal Returns a new `StringSignal` with a constant value, which is equal to the value that the original signal contained immediately after the method was called.
`pinLastValue`	pinLastValue(): ConstStringSignal Returns a `ConstStringSignal` with a constant value, which is equal to the value that the original signal contained immediately before the method was called. Unlike `StringSignal` objects, `ConstStringSignal` objects can be passed as an argument to methods that expect a primitive `string` type.

StringSignal

Contents

Contents

Example

Properties

Methods