#2606: Allow 'dataPath' to be specified on the GraphQL replication pull object to specify where to fetch result documents from

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 Features:
   - Added `RxDatabase.migrationStates()` which returns an observable to observe the state of all ongoing migrations.
+  - Added `dataPath` property to GraphQL replication pull options to allow the document JSON lookup path to configured instead of assuming the document data is always the first child of the response [#2606](https://github.com/pubkey/rxdb/issues/2606)
 
 Bugfixes:
   - Ensure every background task is done when `RxDatabase.destroy()` resolves. [#2938](https://github.com/pubkey/rxdb/issues/2938)

docs-src/replication-graphql.md

@@ -161,6 +161,7 @@ const replicationState = myCollection.syncGraphQL({
     pull: {
         queryBuilder: pullQueryBuilder, // the queryBuilder from above
         modifier: doc => doc // (optional) modifies all pulled documents before they are handeled by RxDB. Returning null will skip the document.
+        dataPath: null // (optional) specifies the object path to access the document(s). Otherwise, the first result of the response data is used.
     },
     deletedFlag: 'deleted', // the flag which indicates if a pulled document is deleted
     live: true // if this is true, rxdb will watch for ongoing changes and sync them, when false, a one-time-replication will be done

src/plugins/replication-graphql/index.ts

@@ -14,6 +14,7 @@ import {
     filter
 } from 'rxjs/operators';
 import GraphQLClient from 'graphql-client';
+import objectPath from 'object-path';
 import {
     promiseWait,
     flatClone,
@@ -234,9 +235,8 @@ export class RxGraphQLReplicationState {
             return false;
         }
 
-        // this assumes that there will be always only one property in the response
-        // is this correct?
-        const data: any[] = result.data[Object.keys(result.data)[0]];
+        const dataPath = (this.pull as any).dataPath || ['data', Object.keys(result.data)[0]];
+        const data: any[] = objectPath.get(result, dataPath);
         const modified: any[] = (await Promise.all(data
             .map(async (doc: any) => await (this.pull as any).modifier(doc))
         )).filter(doc => !!doc);

src/types/plugins/replication-graphql.d.ts

@@ -13,6 +13,7 @@ export type RxGraphQLReplicationQueryBuilder = (doc: any) =>
 export interface GraphQLSyncPullOptions {
     queryBuilder: RxGraphQLReplicationQueryBuilder;
     modifier?: (doc: any) => Promise<any> | any;
+    dataPath?: string;
 }
 export interface GraphQLSyncPushOptions {
     queryBuilder: RxGraphQLReplicationQueryBuilder;

test/unit/replication-graphql.test.ts

@@ -818,6 +818,29 @@ describe('replication-graphql.test.js', () => {
                 server.close();
                 c.database.destroy();
             });
+            it('should pull documents from a custom dataPath if one is specified', async () => {
+                const [c, server] = await Promise.all([
+                    humansCollection.createHumanWithTimestamp(0),
+                    SpawnServer.spawn(getTestData(batchSize))
+                ]);
+                const replicationState = c.syncGraphQL({
+                    url: server.url,
+                    pull: {
+                        queryBuilder,
+                        dataPath: 'data.feedForRxDBReplication'
+                    },
+                    deletedFlag: 'deleted'
+                });
+                assert.strictEqual(replicationState.isStopped(), false);
+
+                await AsyncTestUtil.waitUntil(async () => {
+                    const docs = await c.find().exec();
+                    return docs.length === batchSize;
+                });
+
+                server.close();
+                c.database.destroy();
+            });
             it('pulled docs should be marked with a special revision if syncRevisions is false', async () => {
                 const [c, server] = await Promise.all([
                     humansCollection.createHumanWithTimestamp(0),