feat(data-store-json): BrowserLocalStorageStore (#914)

packages/data-store-json/src/browser-local-storage-store.ts

@@ -0,0 +1,89 @@
+import { IIdentifier, IMessage, ManagedKeyInfo } from '@veramo/core'
+import { ManagedPrivateKey } from '@veramo/key-manager'
+import {
+  DiffCallback,
+  VeramoJsonCache,
+  ClaimTableEntry,
+  CredentialTableEntry,
+  PresentationTableEntry,
+  VeramoJsonStore,
+} from './types'
+
+/**
+ * Implementation of {@link VeramoJsonStore} that uses browser localStorage to store data
+ * 
+ * @example
+ * ```
+ * const dataStore = BrowserLocalStorageStore.fromLocalStorage('veramo-state')
+ * const plugin = new DataStoreJson(dataStore)
+ * ```
+ */
+export class BrowserLocalStorageStore implements VeramoJsonStore {
+  notifyUpdate: DiffCallback
+  dids: Record<string, IIdentifier>
+  keys: Record<string, ManagedKeyInfo>
+  privateKeys: Record<string, ManagedPrivateKey>
+  credentials: Record<string, CredentialTableEntry>
+  claims: Record<string, ClaimTableEntry>
+  presentations: Record<string, PresentationTableEntry>
+  messages: Record<string, IMessage>
+
+  private constructor(private localStorageKey: string) {
+    this.notifyUpdate = async (
+      oldState: VeramoJsonCache,
+      newState: VeramoJsonCache,
+    ) => {
+      this.save(newState)
+    }
+    this.dids = {}
+    this.keys = {}
+    this.privateKeys = {}
+    this.credentials = {}
+    this.claims = {}
+    this.presentations = {}
+    this.messages = {}
+  }
+
+  public static fromLocalStorage(localStorageKey: string): BrowserLocalStorageStore {
+    const store = new BrowserLocalStorageStore(localStorageKey)
+    return store.load()
+  }
+
+  private load(): BrowserLocalStorageStore {
+    if (typeof window !== 'undefined') {
+      const rawCache = window.localStorage.getItem(this.localStorageKey) || '{}'
+      let cache: VeramoJsonCache
+      try {
+        cache = JSON.parse(rawCache)
+      } catch (e: any) {
+        cache = {}
+      }
+      ({
+        dids: this.dids,
+        keys: this.keys,
+        credentials: this.credentials,
+        claims: this.claims,
+        presentations: this.presentations,
+        messages: this.messages,
+        privateKeys: this.privateKeys,
+      } = {
+        dids: {},
+        keys: {},
+        credentials: {},
+        claims: {},
+        presentations: {},
+        messages: {},
+        privateKeys: {},
+        ...cache,
+      })
+    }
+    return this
+  }
+
+  private save(newState: VeramoJsonCache): void {
+    if (typeof window !== 'undefined') {
+      window.localStorage.setItem(this.localStorageKey, JSON.stringify(newState))
+    }
+  }
+
+}

packages/data-store-json/src/index.ts

@@ -21,3 +21,4 @@ export {
 export { DIDStoreJson } from './identifier/did-store'
 export { KeyStoreJson } from './identifier/key-store'
 export { PrivateKeyStoreJson } from './identifier/private-key-store'
+export { BrowserLocalStorageStore } from './browser-local-storage-store'