How to use the @uifabric/utilities.Customizations.getSettings function in @uifabric/utilities

function _getCustomizations>(
  displayName: string,
  context: ICustomizerContext,
  fields?: string[]
): ICustomizationProps {
  // TODO: do we want field props? should fields be part of IComponent and used here?
  // TODO: should we centrally define DefaultFields? (not exported from styling)
  // TOOD: tie this array to ICustomizationProps, such that each array element is keyof ICustomizationProps
  const DefaultFields = ['theme', 'styles', 'tokens'];
  return Customizations.getSettings(fields || DefaultFields, displayName, context.customizations);
}

function _getCustomizations>(
  displayName: string | undefined,
  context: ICustomizerContext,
  fields?: string[]
): ICustomizationProps {
  // TODO: do we want field props? should fields be part of IComponent and used here?
  // TODO: should we centrally define DefaultFields? (not exported from styling)
  // TODO: tie this array to ICustomizationProps, such that each array element is keyof ICustomizationProps
  const DefaultFields = ['theme', 'styles', 'tokens'];
  return Customizations.getSettings(fields || DefaultFields, displayName, context.customizations);
}

function _getCustomizations>(
  displayName: string,
  context: ICustomizerContext,
  fields?: string[]
): ICustomizationProps {
  // TODO: do we want field props? should fields be part of IComponent and used here?
  // TODO: should we centrally define DefaultFields? (not exported from styling)
  // TOOD: tie this array to ICustomizationProps, such that each array element is keyof ICustomizationProps
  const DefaultFields = ['theme', 'styles', 'tokens'];
  return Customizations.getSettings(fields || DefaultFields, displayName, context.customizations);
}

export function getThemedContext(context: ICustomizerContext, scheme?: ISchemeNames, theme?: ITheme): ICustomizerContext {
  let newContext: ICustomizerContext = context;
  let newSettings;

  // Only fall back to context and customizations when theme arg is not provided.
  let schemeSource = theme || Customizations.getSettings(['theme'], undefined, context.customizations).theme;

  if (theme) {
    newSettings = { theme };
  }

  const schemeTheme: ITheme | undefined = scheme && schemeSource && schemeSource.schemes && schemeSource.schemes[scheme];

  // These first two checks are logically redundant but TS doesn't infer schemeSource.schemes is defined when schemeTheme is defined.
  if (schemeSource && schemeTheme && schemeSource !== schemeTheme) {
    newSettings = { theme: schemeTheme };
    newSettings.theme.schemes = schemeSource.schemes;
  }

  if (newSettings) {
    newContext = {
      customizations: {

import { DefaultSpacing } from './DefaultSpacing';
import { loadTheme as legacyLoadTheme } from '@microsoft/load-themed-styles';
import { DefaultEffects } from './DefaultEffects';

let _theme: ITheme = createTheme({
  palette: DefaultPalette,
  semanticColors: _makeSemanticColorsFromPalette(DefaultPalette, false, false),
  fonts: DefaultFontStyles,
  isInverted: false,
  disableGlobalClassNames: false
});
let _onThemeChangeCallbacks: Array<(theme: ITheme) => void> = [];

export const ThemeSettingName = 'theme';

if (!Customizations.getSettings([ThemeSettingName]).theme) {
  const win = getWindow();

  // tslint:disable:no-string-literal no-any
  if (win && (win as any)['FabricConfig'] && (win as any)['FabricConfig'].theme) {
    _theme = createTheme((win as any)['FabricConfig'].theme);
  }
  // tslint:enable:no-string-literal no-any

  // Set the default theme.
  Customizations.applySettings({ [ThemeSettingName]: _theme });
}

/**
 * Gets the theme object
 * @param depComments - Whether to include deprecated tags as comments for deprecated slots.
 */