🚀‍‍ Apollo 🧙 Enchanted InMemoryCache

🚀 Apollo 🛠‍ Tool represented as InMemoryCache 🧙 wrapper for 🗄 storing / 🗃 restoring ✅ selected only 🗂️ queries and for updating ⛓ linked / nested without 🆔 IDs

Content

• Install
• Usage
  • Creating Enchanted InMemoryCache Config
  • Basic usage
• API
  • SubscribedQuery
  • updateQueryHelper: Updater
• Types
• License

Install

$ npm install apollo-enchanted-cache-inmemory -S

or

$ yarn add apollo-enchanted-cache-inmemory

Usage

Creating Enchanted InMemoryCache Config

queries

// * - example for fields as variables used in a query
export const SomeQueryName = 'SomeQueryName';
export const SomeQueryResponseField = 'response';
export const SomeQueryResultField = 'result';
export const QUERY_CREATED_BY_GQL_FUNCTION = gql`
  query ${SomeQueryName} {
    ${SomeQueryResponseField}: ExampleQuery {
      ${SomeQueryResultField} {
        someDataField {
          ...ExampleFragment
        }
        ...ExampleFragment2
      }
    }
  }
  ${ExampleFragment}
  ${ExampleFragment2}
`;
// * - example for fields as variables used in a query
const SomeQueryName2 = 'SomeQueryName2';
const SomeQueryResponseField2 = 'SomeQueryResponseField2';
const SomeQueryResultField2 = 'SomeQueryResultField2';
const SomeQueryDataField2 = 'SomeQueryDataField2';
export const QUERY_CREATED_BY_GQL_FUNCTION_2 = gql`
  query ${SomeQueryName2} {
    ${SomeQueryResponseField2}: SomeDataQuery {
      ${SomeQueryResultField2} {
        ${SomeQueryDataField2} {
          someDataField {
            ...ExampleFragment
          }
          ...ExampleFragment2
        }
      }
    }
  }
  ${ExampleFragment}
  ${ExampleFragment2}
`;
// ** - example for no variables as fields used in a query
export const QUERY_CREATED_BY_GQL_FUNCTION_3 = gql`
  query SomeQueryName3 {
    response: SomeDataQuery {
      result {
        ...ExampleFragment2
      }
    }
  }
  ${ExampleFragment2}
`;

import queries and field names if exist

import { updateQueryHelper } from 'apollo-enchanted-cache-inmemory';
import {
    SomeQueryName,
    SomeQueryResponseField,
    SomeQueryResultField,
    SomeQueryName2,
    SomeQueryResultField2,
    SomeQueryResponseField2,
    SomeQueryDataField2,
    SomeQueryName3,
    QUERY_CREATED_BY_GQL_FUNCTION,
} from './queries';

/** @type SubscribedQueries */
const subscribedQueries = [
  // #1
  // each write into Apollo Cache with updating SomeQueryName
  // will cause storing SomeQueryName asynchronously
  {
    name: SomeQueryName,
    queryNode: QUERY_CREATED_BY_GQL_FUNCTION,
    storeName: SomeQueryName,
    nest: [SomeQueryResponseField], // optional
    // optional XOR - retriever
    retrieveField: SomeQueryResponseField,
    // or
    // optional XOR - retrieveField
    retriever: () => ({...}) // type Retriever
  },
  // #2
  // SomeQueryName2 will update SomeQueryName at SomeQueryResultField
  // with deep merging all nested objects as updateType='deepMerge';
  // data taken from
  // SomeQueryName2.SomeQueryName2.SomeQueryResponseField2.SomeQueryResultField2
  // is identical with SomeQueryName.SomeQueryResponseField.SomeQueryResultField
  // * - example for fields as variables used in a query
  {
    name: SomeQueryName2,
    queryNode: QUERY_CREATED_BY_GQL_FUNCTION,
    updateName: SomeQueryName,
    updater: (sourceQuery, targetQuery) => // type Retriever
      updateQueryHelper({
        sourceQuery,
        sourcePath: [SomeQueryResponseField2, SomeQueryResultField2, SomeQueryDataField2],
        targetQuery,
        targetPath: [SomeQueryResponseField, SomeQueryResultField],
        updateType: 'deepMerge',
      }),
  },
  // #3
  // SomeQueryName3 will update SomeQueryName at someDataField by replace
  // as updateType='replace' by default;
  // data taken from SomeQueryName3.response.result
  // is identical with SomeQueryName.SomeQueryResponseField.SomeQueryResultField
  // after updating SomeQueryName will be stored as tracked by #1 set
  // ** - example for no variables as fields used in a query
  {
    name: 'SomeQueryName3',
    queryNode: QUERY_CREATED_BY_GQL_FUNCTION,
    updateName: SomeQueryName2,
    updater: (sourceQuery, targetQuery) => // type Retriever
      updateQueryHelper({
        sourceQuery,
        sourcePath: ['response', 'result'],
        targetQuery,
        targetPath: ['SomeQueryResponseField', 'result', 'someDataField'],
        // updateType = 'replace' - by default
      }),
  },
];
// ...
export default subscribedQueries;

Basic usage:

Initiation:

import { InMemoryCache } from 'apollo-cache-inmemory';
import ApolloClient from 'apollo-client';
import { withClientState } from 'apollo-link-state';
import { ApolloLink } from 'apollo-link';
// if React Native
// up to RN v0.58
// import { AsyncStorage } from 'react-native';
// since RN v0.59
import AsyncStorage from '@react-native-community/async-storage';
// if Web just use window.LocalStorage

const inMemoryCache = new InMemoryCache({
  // ...
});
// ...
// for debug/log reasons
/** @type Logs */
const logs = {
  logCacheWrite: true,
  beforeHandlers: (cacheData, queryName) => {
    console.log('beforeHandlers', queryName, cacheData.data);
  },
  beforeWrite: (cacheData, queryName) => {
    console.log('beforeWrite', queryName, cacheData.data);
  },
  afterWrite: (cacheData, queryName) => {
    console.log('afterWrite', queryName, cacheData.data);
  },
};

const cache = createEnchantedInMemoryCache(
  inMemoryCache, // instance of `InMemoryCache`
  subscribedQueries, // config type `SubscribedQueries`
  AsyncStorage, // or `LocalStorage` - main app storage, can be omitted if `GraphQLStorage` provided  
  logs, // type Logs
  // GQLStorage, - alternative to `GraphQLStorage` class, e.g. `Realm` (mobile) / `IndexedDB` (web) Wrapper
);
const GQLStorage = cache.GQLStorage; // to get `GQLStorage`
const AppStorage = cache.AppStorage; // to get `AppStorage` - AsyncStorage or LocalStorage
// ...
const stateLink = withClientState({
  cache,
  resolvers,
  defaults,
});
// ...
const apolloClient = new ApolloClient({
  cache,
  link: ApolloLink.from([stateLink]),
});
// ...
export default apolloClient;

Restoring data from storage into cache:

// ...
(async () => {
  // ...
  await cache.restoreAllQueries();
  // ...
})();

API

SubscribedQuery

Array<SubscribedQuery>

Prop	Type	Default	Note
name	string	(required)	query name which changes in Apollo cache will be tracked
queryNode	Query	(required)	Graphql Query created by Apollo's gql utility; type DocumentNode from Apollo Client
storeName	string	(semi-required)*	name used to store and restore in a storage formatted into 'Query:${storeName}' _* either storeName or updateName _
updateName	string	(semi-required)*	query name which will be updated _* either updateName or storeName _
nest	ObjectPath		path to Query field for nesting restored data
retrieveField**	string	(semi-required)*	path to Query field for _* in case if storeName provided _ ** - either retriever or retrieveField
retriever**	Retriever	(semi-required)*	function returns data for storing/restoring _* in case if storeName provided _ ** - either retriever or retrieveField
updater	Updater	(semi-required)*	function returns result with updated data for updating _* - in case if updateName provide

updateQueryHelper: Updater

Prop	Type	Default	Note
sourceQuery	QueryObject	(required)	Object Data of source Query tracked for updating target Query
sourcePath	ObjectPath	[]	path to Data source Query object field
targetQuery	QueryObject		Object Data of target Query should be updated
targetPath	ObjectPath	[]	path to Data target Query object field
updateType	UpdateTypesEnum	replace	replace - just replacing target Data at object some field by source Data rootMerge - merge target Data Object at object field by source Data with replacing tested Data deepMerge - merge target Object Data at all fields (sourcePath of sourceQuery) by source Object Data with same fields (targetPath of targetQuery); begins at source Object field and goes recursively into the depths
sourceDefault	any	null	data to be used for updating the target Object if no present in the source Object

Types

type ArrayPath = Array<string | number>; // ['a', 'b', 0, 'c', 1]

type ObjectPath = ArrayPath | string; // ['a', 'b', 'c', 0] | 'a.b.c.0'

type QueryObject<Data> = { Object; Data }; // Query result data

type Updater = <T1, T2, T3>(
  sourceQuery: QueryObject<T1>,
  targetQuery: QueryObject<T2>,
) => QueryObject<T3>;

type Retriever = <T1, T2, T3>(
  sourceQuery: QueryObject<T1>,
  targetQuery: QueryObject<T2>,
) => QueryObject<T3>;

type LinkedQuery = {
  name: string;
  queryNode: DocumentNode; // Apollo Query definition, returned by gql`...`
  updateName: string;
  updater: Updater;
};

type StoredQuery = {
  name: string;
  queryNode: DocumentNode; // Apollo Query definition, returned by gql`...`
  storeName: string;
  nest?: ObjectPath;
  retrieveField?: string;
  retriever?: Retriever;
};

type SubscribedQuery = LinkedQuery | StoredQuery;

type SubscribedQueries = Array<SubscribedQuery>;

type DepTrackingCache = { data: Object; depend: Object };

type Logger = (cacheData: DepTrackingCache, queryName: String) => void;

type Logs = {
    logCacheWrite: Boolean,
    beforeHandlers: Logger,
    beforeWrite: Logger,
    afterWrite: Logger,
};

enum UpdateTypesEnum {
  replace = 'replace',
  rootMerge = 'rootMerge',
  deepMerge = 'deepMerge',
}

License

Copyright (c) 2019 KosiakMD (Anton Kosiak)

Licensed under the The MIT License (MIT) (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

https://raw.githubusercontent.com/airbnb/react-native-maps/master/LICENSE

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.