ngx-webstorage-service
Version:
Angular service wrappers for the webstorage API
122 lines • 14.7 kB
JavaScript
import { BaseStorageService } from './base-storage.service';
import { StorageTranscoders } from './storage-transcoders';
/**
* An implementation of `StorageService` interface that uses an underlying (web) `Storage` object, such as `localStorage` and
* `sessionStorage`, as backing data store. This class basically wraps the `Storage` object so it can be accessed through the
* `StorageService` interface.
*/
export class WebStorageService extends BaseStorageService {
/**
* Creates a new `WebStorageService` instance that uses the specified (web) storage object as underlying backing storage.
*
* @param storage Storage object which is to be wrapped in a class that implements the `StorageService` interface.
*/
constructor(storage) {
super(StorageTranscoders.JSON);
this.storage = storage;
}
/**
* Checks whether an entry with the specified key exists in the storage.
*
* @param key Identifier of the entry for which its presence in the storage is to be checked.
* @returns `true` if an entry with the specified key exists in the storage, `false` if not.
*/
has(key) {
return this.storage.getItem(key) !== null;
}
/**
* Removes the entry that is identified by the specified key. Attempting to remove an entry for an unknown key will have no effect.
* Attempting to retrieve an entry via the `get` method after it has been removed will result in `undefined`.
*
* @param key Identifier of the entry which is to be removed.
*/
remove(key) {
this.storage.removeItem(key);
}
/**
* Clears the storage by removing all entries. Subsequent `get(x)` calls for a key *x* will return `undefined`, until a new value is set
* for key *x*.
*/
clear() {
this.storage.clear();
}
/**
* Performs the actual retrieval of a value from storage.
*
* @param key Identifier of the entry whose value is to be retrieved.
* @returns The value that is stored for the specified entry or `undefined` if no entry exists for the specified key.
*/
getItem(key) {
const value = this.storage.getItem(key);
return value !== null ? value : undefined;
}
/**
* Stores the provided value using specified key in the storage.
*
* @param key Identifier of the entry for which the value is to be stored.
* @param value The value that is to be stored.
*/
setItem(key, value) {
return this.storage.setItem(key, value);
}
}
/**
* Checks whether the specified (web) storage is available and functional. This might not be the case for older browsers. However even
* certain browsers that do support the web storage API can, under some circumstances, have non functional storage objects. For example,
* Safari is known to have `localStorage` and `sessionStorage` throw exceptions in private mode.
*
* @param storage Storage object which is to be tested for availability.
* @returns `true` if the specified storage can be used, `false` if not.
*/
export function isStorageAvailable(storage) {
// Check if storage is available.
if (!storage) {
return false;
}
// Check if the storage can actually be accessed.
try {
const now = Date.now();
const testItemKey = `storage-test-entry-${now}`;
const testItemValue = `storage-test-value-${now}`;
storage.setItem(testItemKey, testItemValue);
const retrievedItemValue = storage.getItem(testItemKey);
storage.removeItem(testItemKey);
return retrievedItemValue === testItemValue;
}
catch (error) {
return false;
}
}
/**
* Checks whether session storage is available and functional. This might not be the case for older browsers. However even certain browsers
* that do support the web storage API can, under some circumstances, have non functional storage objects. For example, Safari is known to
* have `sessionStorage` throw exceptions in private mode.
*
* @returns `true` if session storage can be used, `false` if not.
*/
export function isSessionStorageAvailable() {
try {
if (typeof sessionStorage !== 'undefined') {
return isStorageAvailable(sessionStorage);
}
}
catch { }
return false;
}
/**
* Checks whether local storage is available and functional. This might not be the case for older browsers. However even certain browsers
* that do support the web storage API can, under some circumstances, have non functional storage objects. For example, Safari is known to
* have `localStorage` throw exceptions in private mode.
*
* @returns `true` if local storage can be used, `false` if not.
*/
export function isLocalStorageAvailable() {
try {
if (typeof localStorage !== 'undefined') {
return isStorageAvailable(localStorage);
}
}
catch { }
return false;
}
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This class basically wraps the `Storage` object so it can be accessed through the\n * `StorageService` interface.\n */\nexport class WebStorageService extends BaseStorageService<any> {\n\n    /**\n     * Creates a new `WebStorageService` instance that uses the specified (web) storage object as underlying backing storage.\n     *\n     * @param storage Storage object which is to be wrapped in a class that implements the `StorageService` interface.\n     */\n    constructor(private readonly storage: Storage) {\n        super(StorageTranscoders.JSON);\n    }\n\n    /**\n     * Checks whether an entry with the specified key exists in the storage.\n     *\n     * @param   key Identifier of the entry for which its presence in the storage is to be checked.\n     * @returns     `true` if an entry with the specified key exists in the storage, `false` if not.\n     */\n    public has(key: string): boolean {\n        return this.storage.getItem(key) !== null;\n    }\n\n    /**\n     * Removes the entry that is identified by the specified key. Attempting to remove an entry for an unknown key will have no effect.\n     * Attempting to retrieve an entry via the `get` method after it has been removed will result in `undefined`.\n     *\n     * @param key Identifier of the entry which is to be removed.\n     */\n    public remove(key: string): void {\n        this.storage.removeItem(key);\n    }\n\n    /**\n     * Clears the storage by removing all entries. Subsequent `get(x)` calls for a key *x* will return `undefined`, until a new value is set\n     * for key *x*.\n     */\n    public clear(): void {\n        this.storage.clear();\n    }\n\n    /**\n     * Performs the actual retrieval of a value from storage.\n     *\n     * @param   key Identifier of the entry whose value is to be retrieved.\n     * @returns     The value that is stored for the specified entry or `undefined` if no entry exists for the specified key.\n     */\n    protected getItem(key: string): string | undefined {\n        const value = this.storage.getItem(key);\n\n        return value !== null ? value : undefined;\n    }\n\n    /**\n     * Stores the provided value using specified key in the storage.\n     *\n     * @param key   Identifier of the entry for which the value is to be stored.\n     * @param value The value that is to be stored.\n     */\n    protected setItem(key: string, value: string): void {\n        return this.storage.setItem(key, value);\n    }\n\n}\n\n/**\n * Checks whether the specified (web) storage is available and functional. This might not be the case for older browsers. However even\n * certain browsers that do support the web storage API can, under some circumstances, have non functional storage objects. For example,\n * Safari is known to have `localStorage` and `sessionStorage` throw exceptions in private mode.\n *\n * @param   storage Storage object which is to be tested for availability.\n * @returns         `true` if the specified storage can be used, `false` if not.\n */\nexport function isStorageAvailable(storage: Storage): boolean {\n    // Check if storage is available.\n    if (!storage) {\n        return false;\n    }\n\n    // Check if the storage can actually be accessed.\n    try {\n        const now = Date.now();\n        const testItemKey = `storage-test-entry-${now}`;\n        const testItemValue = `storage-test-value-${now}`;\n        storage.setItem(testItemKey, testItemValue);\n        const retrievedItemValue = storage.getItem(testItemKey);\n        storage.removeItem(testItemKey);\n\n        return retrievedItemValue === testItemValue;\n    } catch (error) {\n        return false;\n    }\n}\n\n/**\n * Checks whether session storage is available and functional. This might not be the case for older browsers. However even certain browsers\n * that do support the web storage API can, under some circumstances, have non functional storage objects. For example, Safari is known to\n * have `sessionStorage` throw exceptions in private mode.\n *\n * @returns `true` if session storage can be used, `false` if not.\n */\nexport function isSessionStorageAvailable(): boolean {\n    try {\n        if (typeof sessionStorage as any !== 'undefined') {\n            return isStorageAvailable(sessionStorage);\n        }\n    } catch {}\n\n    return false;\n}\n\n/**\n * Checks whether local storage is available and functional. This might not be the case for older browsers. However even certain browsers\n * that do support the web storage API can, under some circumstances, have non functional storage objects. For example, Safari is known to\n * have `localStorage` throw exceptions in private mode.\n *\n * @returns `true` if local storage can be used, `false` if not.\n */\nexport function isLocalStorageAvailable(): boolean {\n    try {\n        if (typeof localStorage as any !== 'undefined') {\n            return isStorageAvailable(localStorage);\n        }\n    } catch {}\n\n    return false;\n}\n"]}