gristlabs_grist-core/app/client/lib/localStorageObs.ts

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import {safeJsonParse} from 'app/common/gutil';
import {Observable} from 'grainjs';
import {getSessionStorage, getStorage} from 'app/client/lib/storage';
function getStorageBoolObs(store: Storage, key: string, defValue: boolean) {
const storedNegation = defValue ? 'false' : 'true';
const obs = Observable.create(null, store.getItem(key) === storedNegation ? !defValue : defValue);
obs.addListener((val) => val === defValue ? store.removeItem(key) : store.setItem(key, storedNegation));
return obs;
}
/**
* Helper to create a boolean observable whose state is stored in localStorage.
*
* Optionally, a default value of true will make the observable start off as true. Note that the
* same default value should be used for an observable every time it's created.
*/
export function localStorageBoolObs(key: string, defValue = false): Observable<boolean> {
return getStorageBoolObs(getStorage(), key, defValue);
}
/**
* Similar to `localStorageBoolObs`, but always uses sessionStorage (or an in-memory equivalent).
*/
export function sessionStorageBoolObs(key: string, defValue = false): Observable<boolean> {
return getStorageBoolObs(getSessionStorage(), key, defValue);
}
/**
* Helper to create a string observable whose state is stored in localStorage.
*/
export function localStorageObs(key: string, defaultValue?: string): Observable<string|null> {
const store = getStorage();
const obs = Observable.create<string|null>(null, store.getItem(key) ?? defaultValue ?? null);
obs.addListener((val) => (val === null) ? store.removeItem(key) : store.setItem(key, val));
return obs;
}
/**
* Helper to create a JSON observable whose state is stored in localStorage.
*/
export function localStorageJsonObs<T>(key: string, defaultValue: T): Observable<T> {
const store = getStorage();
const currentValue = safeJsonParse(store.getItem(key) || '', defaultValue ?? null);
const obs = Observable.create<T>(null, currentValue);
obs.addListener((val) => (val === null) ? store.removeItem(key) : store.setItem(key, JSON.stringify(val ?? null)));
return obs;
}