feat(proxy datasource): JSON server configuration launch (#2791)

* feat: delegating dicom web proxy datasource

* fix: configurably allow WADO image loader to issue preflight OPTIONS request

* Added documentation and fixed up some error handling from PR review

* review comments changes

* another small code review fix

extensions/default/src/DicomWebProxyDataSource/index.js

@@ -0,0 +1,84 @@
+import { IWebApiDataSource } from '@ohif/core';
+import { createDicomWebApi } from '../DicomWebDataSource/index';
+
+/**
+ * This datasource is initialized with a url that returns a JSON object with a
+ * dicomWeb datasource configuration array present in a "servers" object.
+ *
+ * Only the first array item is parsed, if there are multiple items in the
+ * dicomWeb configuration array
+ *
+ */
+function createDicomWebProxyApi(
+  dicomWebProxyConfig,
+  UserAuthenticationService
+) {
+  const { name } = dicomWebProxyConfig;
+  let dicomWebDelegate = undefined;
+
+  const implementation = {
+    initialize: async ({ params, query }) => {
+      let studyInstanceUIDs = [];
+
+      // there seem to be a couple of variations of the case for this parameter
+      const queryStudyInstanceUIDs =
+        query.get('studyInstanceUIDs') || query.get('studyInstanceUids');
+      if (!queryStudyInstanceUIDs) {
+        throw new Error(`No studyInstanceUids in request for '${name}'`);
+      }
+
+      const url = query.get('url');
+
+      if (!url) {
+        throw new Error(`No url for '${name}'`);
+      } else {
+        const response = await fetch(url);
+        let data = await response.json();
+        if (!data.servers?.dicomWeb?.[0]) {
+          throw new Error('Invalid configuration returned by url');
+        }
+
+        dicomWebDelegate = createDicomWebApi(
+          data.servers.dicomWeb[0],
+          UserAuthenticationService
+        );
+        studyInstanceUIDs = queryStudyInstanceUIDs.split(';');
+      }
+      return studyInstanceUIDs;
+    },
+    query: {
+      studies: {
+        search: params => dicomWebDelegate.query.studies.search(params),
+      },
+      series: {
+        search: (...args) => dicomWebDelegate.query.series.search(...args),
+      },
+      instances: {
+        search: (studyInstanceUid, queryParameters) =>
+          dicomWebDelegate.query.instances.search(
+            studyInstanceUid,
+            queryParameters
+          ),
+      },
+    },
+    retrieve: {
+      directURL: (...args) => dicomWebDelegate.retrieve.directURL(...args),
+      series: {
+        metadata: (...args) =>
+          dicomWebDelegate.retrieve.series.metadata(...args),
+      },
+    },
+    store: {
+      dicom: (...args) => dicomWebDelegate.store(...args),
+    },
+    deleteStudyMetadataPromise: (...args) =>
+      dicomWebDelegate.deleteStudyMetadataPromise(...args),
+    getImageIdsForDisplaySet: (...args) =>
+      dicomWebDelegate.getImageIdsForDisplaySet(...args),
+    getImageIdsForInstance: (...args) =>
+      dicomWebDelegate.getImageIdsForInstance(...args),
+  };
+  return IWebApiDataSource.create(implementation);
+}
+
+export { createDicomWebProxyApi };

extensions/default/src/getDataSourcesModule.js

@@ -5,6 +5,7 @@
 import { createDicomWebApi } from './DicomWebDataSource/index.js';
 import { createDicomJSONApi } from './DicomJSONDataSource/index.js';
 import { createDicomLocalApi } from './DicomLocalDataSource/index.js';
+import { createDicomWebProxyApi } from './DicomWebProxyDataSource/index.js';
 
 /**
  *
@@ -16,6 +17,11 @@ function getDataSourcesModule() {
       type: 'webApi',
       createDataSource: createDicomWebApi,
     },
+    {
+      name: 'dicomwebproxy',
+      type: 'webApi',
+      createDataSource: createDicomWebProxyApi,
+    },
     {
       name: 'dicomjson',
       type: 'jsonApi',