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',

platform/docs/docs/configuration/dataSources/dicom-web-proxy.md

@@ -0,0 +1,54 @@
+---
+sidebar_position: 4
+sidebar_label: DICOMweb Proxy
+---
+
+# DICOMweb Proxy
+
+You can launch the OHIF Viewer with a url that returns a JSON file which
+contains a DICOMWeb configuration. The DICOMweb Proxy constructs a DICOMweb
+datasource and delegates subsequent requests for metadata and images to that.
+
+Usage is similar to that of the [DICOM JSON](./dicom-json.md) datasource and
+might look like
+
+`https://v3-demo.ohif.org/viewer/dicomwebproxy?url=https://ohif-dicom-json-example.s3.amazonaws.com/dicomweb.json`
+
+The url to the location of the JSON file is passed in the query
+after the `dicomwebproxy` string, which is
+`https://ohif-dicom-json-example.s3.amazonaws.com/dicomweb.json` (this json file
+does not exist at the moment of this writing).
+
+## DICOMweb JSON configuration sample
+
+The json returned by the url in this example contains a dicomweb configuration
+(see [DICOMweb](dicom-web.md)), in a "servers" object, which is then used to
+construct a dynamic DICOMweb datasource to delegate requests to. Here is an
+example configuration that might be returned using the url parameter.
+
+```json
+{
+  "servers": {
+    "dicomWeb": [
+      {
+        "name": "DCM4CHEE",
+        "wadoUriRoot": "https://server.dcmjs.org/dcm4chee-arc/aets/DCM4CHEE/wado",
+        "qidoRoot": "https://server.dcmjs.org/dcm4chee-arc/aets/DCM4CHEE/rs",
+        "wadoRoot": "https://server.dcmjs.org/dcm4chee-arc/aets/DCM4CHEE/rs",
+        "qidoSupportsIncludeField": true,
+        "supportsReject": true,
+        "imageRendering": "wadors",
+        "thumbnailRendering": "wadors",
+        "enableStudyLazyLoad": true,
+        "supportsFuzzyMatching": true,
+        "supportsWildcard": true
+      }
+    ]
+  }
+}
+```
+
+The DICOMweb Proxy expects the json returned by the url parameter it is invoked
+with to include a servers object which contains a "dicomWeb" configuration array
+as above. It will only consider the first array item in the dicomWeb
+configuration.

platform/viewer/public/config/default.js

@@ -53,6 +53,14 @@ window.config = {
         useBulkDataURI: false,
       },
     },
+    {
+      friendlyName: 'dicomweb delegating proxy',
+      namespace: '@ohif/extension-default.dataSourcesModule.dicomwebproxy',
+      sourceName: 'dicomwebproxy',
+      configuration: {
+        name: 'dicomwebproxy',
+      },
+    },
     {
       friendlyName: 'dicom json',
       namespace: '@ohif/extension-default.dataSourcesModule.dicomjson',