Prefs

Manages persistent application preferences.

All reads and writes operate in-memory. Call persist() to save changes to disk. Preferences are stored in prefs.json under the application user data directory.

Example 

import { prefs } from '@mobrowser/api';

prefs.setNumber('editor.zoom', 1.5)
prefs.persist()

Methods 

getNumber() 

getNumber(key: string, defaultValue?: number): number;

Returns the number stored under key, or defaultValue if the key is missing or holds a non-number value.

Defaults to 0 when no defaultValue is provided and the key is missing or has the wrong type.

Example 

import { prefs } from '@mobrowser/api';

const zoom = prefs.getNumber('editor.zoom', 1.0)

setNumber() 

setNumber(key: string, value: number): void;

Stores a number under the given key.

Empty keys and non-finite values (NaN, Infinity) are silently ignored.

Example 

import { prefs } from '@mobrowser/api';

prefs.setNumber('editor.fontSize', 14)

hasNumber() 

hasNumber(key: string): boolean;

Returns true if a number value is stored under key.

Example 

import { prefs } from '@mobrowser/api';

if (prefs.hasNumber('editor.zoom')) {
  const zoom = prefs.getNumber('editor.zoom')
}

getBoolean() 

getBoolean(key: string, defaultValue?: boolean): boolean;

Returns the boolean stored under key, or defaultValue if the key is missing or holds a non-boolean value.

Defaults to false when no defaultValue is provided and the key is missing or has the wrong type.

Example 

import { prefs } from '@mobrowser/api';

const wordWrap = prefs.getBoolean('editor.wordWrap', false)

setBoolean() 

setBoolean(key: string, value: boolean): void;

Stores a boolean under the given key.

Empty keys are silently ignored.

Example 

import { prefs } from '@mobrowser/api';

prefs.setBoolean('ui.sidebar.visible', false)

hasBoolean() 

hasBoolean(key: string): boolean;

Returns true if a boolean value is stored under key.

Example 

import { prefs } from '@mobrowser/api';

if (prefs.hasBoolean('editor.wordWrap')) {
  const wordWrap = prefs.getBoolean('editor.wordWrap')
}

getString() 

getString(key: string, defaultValue?: string): string;

Returns the string stored under key, or defaultValue if the key is missing or holds a non-string value.

Defaults to '' (empty string) when no defaultValue is provided and the key is missing or has the wrong type.

Example 

import { prefs } from '@mobrowser/api';

const theme = prefs.getString('ui.theme', 'light')

setString() 

setString(key: string, value: string): void;

Stores a string under the given key.

Empty keys are silently ignored.

Example 

import { prefs } from '@mobrowser/api';

prefs.setString('ui.theme', 'dark')

hasString() 

hasString(key: string): boolean;

Returns true if a string value is stored under key.

Example 

import { prefs } from '@mobrowser/api';

if (prefs.hasString('ui.theme')) {
  const theme = prefs.getString('ui.theme')
}

setObject() 

setObject(key: string, value: object): void;

Stores a plain JSON object under the given key.

Empty keys and non-plain-object values are silently ignored. The object has to contain nested JSON-compatible primitives, arrays, and objects.

Nested arrays/objects are supported up to a maximum depth of 20 levels. Unsupported values (functions, symbols, class instances, cyclic references) cause the entire write to be silently skipped.

Example 

import { prefs } from '@mobrowser/api';

prefs.setObject('ui.windowState', {
  width: 1024, height: 768, x: 0, y: 0
})

hasObject() 

hasObject(key: string): boolean;

Returns true if an object value is stored under key.

Example 

import { prefs } from '@mobrowser/api';

if (prefs.hasObject('ui.windowState')) {
  const state = prefs.getObject('ui.windowState')
}

setArray() 

setArray(key: string, value: unknown[]): void;

Stores a JSON array under the given key.

Empty keys and non-array values are silently ignored. Array elements have to be JSON-compatible primitives, arrays, or plain objects.

Nested arrays/objects are supported up to a maximum depth of 20 levels. Unsupported values (functions, symbols, class instances, cyclic references) cause the entire write to be silently skipped.

Example 

import { prefs } from '@mobrowser/api';

prefs.setArray('app.recentFiles', ['/home/user/doc.txt', '/home/user/img.png'])

hasArray() 

hasArray(key: string): boolean;

Returns true if an array value is stored under key.

Example 

import { prefs } from '@mobrowser/api';

if (prefs.hasArray('app.recentFiles')) {
  const files = prefs.getArray<string>('app.recentFiles')
}

remove() 

remove(key: string): void;

Removes a single key from the in-memory cache.

Empty keys are silently ignored.

Example 

import { prefs } from '@mobrowser/api';

if (prefs.getString('ui.theme')) {
  prefs.remove('ui.theme')
}

clear() 

clear(): void;

Removes all keys from the in-memory cache.

Example 

import { prefs } from '@mobrowser/api';

prefs.clear()

persist() 

persist(): boolean;

Saves the preferences to disk under the application user data directory.

Until this method is called, changes are in-memory only and will be lost if the application exits.

Return value 

true if the preferences are saved successfully, false if the save fails for any reason.

Example 

import { prefs } from '@mobrowser/api';

prefs.setString('ui.theme', 'dark')
prefs.setNumber('editor.fontSize', 14)

if (!prefs.persist()) {
  console.error('Failed to save preferences')
}