Cache redirects

CHANGELOG.md

@@ -3,6 +3,7 @@
 Expect active development and potentially significant breaking changes in the `0.x` track. We'll try to be diligent about releasing a `1.0` version in a timely fashion (ideally within 3 to 6 months), to signal the start of a more stable API.
 
 ### vNEXT
+- Implement cache redirects with custom resolvers [PR #921](https://github.com/apollostack/apollo-client/pull/921)
 
 ### 0.5.4
 - Fix a bug that caused apollo-client to catch errors thrown in Observer.next callbacks [PR #910](https://github.com/apollostack/apollo-client/pull/910)

src/ApolloClient.ts

@@ -25,6 +25,10 @@ import {
   Store,
 } from './store';
 
+import {
+  CustomResolverMap,
+} from './data/readFromStore';
+
 import {
   QueryManager,
   ApolloQueryResult,
@@ -145,6 +149,7 @@ export default class ApolloClient {
     mutationBehaviorReducers = {} as MutationBehaviorReducerMap,
     addTypename = true,
     queryTransformer,
+    customResolvers,
   }: {
     networkInterface?: NetworkInterface,
     reduxRootKey?: string,
@@ -158,6 +163,7 @@ export default class ApolloClient {
     mutationBehaviorReducers?: MutationBehaviorReducerMap,
     addTypename?: boolean,
     queryTransformer?: any,
+    customResolvers?: CustomResolverMap,
   } = {}) {
     if (reduxRootKey && reduxRootSelector) {
       throw new Error('Both "reduxRootKey" and "reduxRootSelector" are configured, but only one of two is allowed.');
@@ -206,6 +212,7 @@ export default class ApolloClient {
     this.reducerConfig = {
       dataIdFromObject,
       mutationBehaviorReducers,
+      customResolvers,
     };
 
     this.watchQuery = this.watchQuery.bind(this);

src/core/QueryManager.ts

@@ -141,6 +141,7 @@ export class QueryManager {
   private resultTransformer: ResultTransformer;
   private resultComparator: ResultComparator;
   private reducerConfig: ApolloReducerConfig;
+
   // TODO REFACTOR collect all operation-related info in one place (e.g. all these maps)
   // this should be combined with ObservableQuery, but that needs to be expanded to support
   // mutations and subscriptions as well.
@@ -381,6 +382,7 @@ export class QueryManager {
                 query: this.queryDocuments[queryId],
                 variables: queryStoreValue.previousVariables || queryStoreValue.variables,
                 returnPartialData: options.returnPartialData || options.noFetch,
+                config: this.reducerConfig,
               }),
               loading: queryStoreValue.loading,
               networkStatus: queryStoreValue.networkStatus,
@@ -479,6 +481,7 @@ export class QueryManager {
         store: this.reduxRootSelector(this.store.getState()).data,
         returnPartialData: true,
         variables,
+        config: this.reducerConfig,
       });
 
       // If we're in here, only fetch if we have missing fields
@@ -733,6 +736,7 @@ export class QueryManager {
       query: document,
       variables,
       returnPartialData: false,
+      config: this.reducerConfig,
     };
 
     try {
@@ -951,6 +955,7 @@ export class QueryManager {
               variables,
               returnPartialData: returnPartialData || noFetch,
               query: document,
+              config: this.reducerConfig,
             });
             // ensure multiple errors don't get thrown
             /* tslint:disable */

src/data/readFromStore.ts

@@ -22,6 +22,10 @@ import {
   getQueryDefinition,
 } from '../queries/getFromAST';
 
+import {
+  ApolloReducerConfig,
+} from '../store';
+
 export type DiffResult = {
   result?: any;
   isMissing?: boolean;
@@ -32,8 +36,17 @@ export type ReadQueryOptions = {
   query: Document,
   variables?: Object,
   returnPartialData?: boolean,
+  config?: ApolloReducerConfig,
 }
 
+export type CustomResolver = (rootValue: any, args: { [argName: string]: any }) => any;
+
+export type CustomResolverMap = {
+  [typeName: string]: {
+    [fieldName: string]: CustomResolver
+  }
+};
+
 /**
  * Resolves the result of a query solely from the store (i.e. never hits the server).
  *
@@ -54,12 +67,14 @@ export function readQueryFromStore({
   query,
   variables,
   returnPartialData = false,
+  config,
 }: ReadQueryOptions): Object {
   const { result } = diffQueryAgainstStore({
     query,
     store,
     returnPartialData,
     variables,
+    config,
   });
 
   return result;
@@ -69,6 +84,7 @@ type ReadStoreContext = {
   store: NormalizedCache;
   returnPartialData: boolean;
   hasMissingField: boolean;
+  customResolvers: CustomResolverMap;
 }
 
 let haveWarned = false;
@@ -130,6 +146,20 @@ const readStoreResolver: Resolver = (
   const fieldValue = (obj || {})[storeKeyName];
 
   if (typeof fieldValue === 'undefined') {
+    if (context.customResolvers && obj && (obj.__typename || objId === 'ROOT_QUERY')) {
+      const typename = obj.__typename || 'Query';
+
+      // Look for the type in the custom resolver map
+      const type = context.customResolvers[typename];
+      if (type) {
+        // Look for the field in the custom resolver map
+        const resolver = type[fieldName];
+        if (resolver) {
+          return resolver(obj, args);
+        }
+      }
+    }
+
     if (! context.returnPartialData) {
       throw new Error(`Can't find field ${storeKeyName} on object (${objId}) ${JSON.stringify(obj, null, 2)}.
 Perhaps you want to use the \`returnPartialData\` option?`);
@@ -161,15 +191,18 @@ export function diffQueryAgainstStore({
   query,
   variables,
   returnPartialData = true,
+  config,
 }: ReadQueryOptions): DiffResult {
   // Throw the right validation error by trying to find a query in the document
   getQueryDefinition(query);
 
   const context: ReadStoreContext = {
+    // Global settings
     store,
     returnPartialData,
+    customResolvers: config && config.customResolvers,
 
-    // Filled in during execution
+    // Flag set during execution
     hasMissingField: false,
   };
 

src/data/resultReducers.ts

@@ -46,9 +46,12 @@ export function createStoreReducer(
       query: document,
       variables,
       returnPartialData: true,
+      config,
     });
     // TODO add info about networkStatus
+
     const nextResult = resultReducer(currentResult, action); // action should include operation name
+
     if (currentResult !== nextResult) {
       return writeResultToStore({
         dataId: 'ROOT_QUERY',

src/data/storeUtils.ts

@@ -149,6 +149,14 @@ export function isIdValue(idObject: StoreValue): idObject is IdValue {
   return (isObject(idObject) && (idObject as (IdValue | JsonValue)).type === 'id');
 }
 
+export function toIdValue(id: string, generated = false): IdValue {
+  return {
+    type: 'id',
+    id,
+    generated,
+  };
+}
+
 export function isJsonValue(jsonObject: StoreValue): jsonObject is JsonValue {
   return (isObject(jsonObject) && (jsonObject as (IdValue | JsonValue)).type === 'json');
 }

src/index.ts

@@ -67,6 +67,10 @@ import {
   ApolloQueryResult,
 } from './core/QueryManager';
 
+import {
+  toIdValue,
+} from './data/storeUtils';
+
 // We expose the print method from GraphQL so that people that implement
 // custom network interfaces can turn query ASTs into query strings as needed.
 export {
@@ -94,6 +98,8 @@ export {
 
   ApolloQueryResult,
 
+  toIdValue,
+
   // internal type definitions for export
   WatchQueryOptions,
   MutationOptions,

src/store.ts

@@ -40,6 +40,10 @@ import {
   MutationBehaviorReducerMap,
 } from './data/mutationResults';
 
+import {
+  CustomResolverMap,
+} from './data/readFromStore';
+
 import assign = require('lodash.assign');
 
 export interface Store {
@@ -151,9 +155,10 @@ export function createApolloStore({
 }
 
 
-export interface ApolloReducerConfig {
+export type ApolloReducerConfig = {
   dataIdFromObject?: IdGetter;
   mutationBehaviorReducers?: MutationBehaviorReducerMap;
+  customResolvers?: CustomResolverMap;
 }
 
 export function getDataWithOptimisticResults(store: Store): NormalizedCache {

test/QueryManager.ts

@@ -3166,5 +3166,4 @@ describe('QueryManager', () => {
 
     // We have an unhandled error warning from the `subscribe` above, which has no `error` cb
   });
-
 });

test/customResolvers.ts

@@ -0,0 +1,62 @@
+import mockNetworkInterface from './mocks/mockNetworkInterface';
+import gql from 'graphql-tag';
+import { assert } from 'chai';
+import ApolloClient, { toIdValue } from '../src';
+
+import { NetworkStatus } from '../src/queries/store';
+
+describe('custom resolvers', () => {
+  it(`works for cache redirection`, () => {
+    const dataIdFromObject = (obj: any) => {
+      return obj.id;
+    };
+
+    const listQuery = gql`{ people { id name } }`;
+
+    const listData = {
+      people: [
+        {
+          id: '4',
+          name: 'Luke Skywalker',
+          __typename: 'Person',
+        },
+      ],
+    };
+
+    const netListQuery = gql`{ people { id name __typename } }`;
+
+    const itemQuery = gql`{ person(id: 4) { id name } }`;
+
+    // We don't expect the item query to go to the server at all
+    const networkInterface = mockNetworkInterface({
+      request: { query: netListQuery },
+      result: { data: listData },
+    });
+
+    const client = new ApolloClient({
+      networkInterface,
+      customResolvers: {
+        Query: {
+          person: (_, args) => toIdValue(args['id']),
+        },
+      },
+      dataIdFromObject,
+    });
+
+    return client.query({ query: listQuery }).then(() => {
+      return client.query({ query: itemQuery });
+    }).then((itemResult) => {
+      assert.deepEqual(itemResult, {
+        loading: false,
+        networkStatus: NetworkStatus.ready,
+        data: {
+          person: {
+            __typename: 'Person',
+            id: '4',
+            name: 'Luke Skywalker',
+          },
+        },
+      });
+    });
+  });
+});

test/readFromStore.ts

@@ -569,4 +569,81 @@ describe('reading from the store', () => {
       simpleArray: [null, 'two', 'three'],
     });
   });
+
+  it('runs a query with custom resolvers for a computed field', () => {
+    const result = {
+      __typename: 'Thing',
+      id: 'abcd',
+      stringField: 'This is a string!',
+      numberField: 5,
+      nullField: null,
+    } as StoreObject;
+
+    const store = {
+      'ROOT_QUERY': result,
+    } as NormalizedCache;
+
+    const queryResult = readQueryFromStore({
+      store,
+      query: gql`
+        query {
+          stringField
+          numberField
+          computedField(extra: "bit") @client
+        }
+      `,
+      config: {
+        customResolvers: {
+          Thing: {
+            computedField: (obj, args) => obj.stringField + obj.numberField + args['extra'],
+          },
+        },
+      },
+    });
+
+    // The result of the query shouldn't contain __data_id fields
+    assert.deepEqual(queryResult, {
+      stringField: result['stringField'],
+      numberField: result['numberField'],
+      computedField: 'This is a string!5bit',
+    });
+  });
+
+  it('runs a query with custom resolvers for a computed field on root Query', () => {
+    const result = {
+      id: 'abcd',
+      stringField: 'This is a string!',
+      numberField: 5,
+      nullField: null,
+    } as StoreObject;
+
+    const store = {
+      'ROOT_QUERY': result,
+    } as NormalizedCache;
+
+    const queryResult = readQueryFromStore({
+      store,
+      query: gql`
+        query {
+          stringField
+          numberField
+          computedField(extra: "bit") @client
+        }
+      `,
+      config: {
+        customResolvers: {
+          Query: {
+            computedField: (obj, args) => obj.stringField + obj.numberField + args['extra'],
+          },
+        },
+      },
+    });
+
+    // The result of the query shouldn't contain __data_id fields
+    assert.deepEqual(queryResult, {
+      stringField: result['stringField'],
+      numberField: result['numberField'],
+      computedField: 'This is a string!5bit',
+    });
+  });
 });