ohif-viewer/extensions/default/src/DicomWebDataSource/retrieveStudyMetadata.js
2020-05-15 13:01:58 +01:00

72 lines
2.3 KiB
JavaScript

import RetrieveMetadata from './services/wado/retrieveMetadata.js';
const moduleName = 'RetrieveStudyMetadata';
// Cache for promises. Prevents unnecessary subsequent calls to the server
const StudyMetaDataPromises = new Map();
/**
* Retrieves study metadata
*
* @param {Object} server Object with server configuration parameters
* @param {string} StudyInstanceUID The UID of the Study to be retrieved
* @param {Object} [filters] - Object containing filters to be applied on retrieve metadata process
* @param {string} [filter.seriesInstanceUID] - series instance uid to filter results against
* @returns {Promise} that will be resolved with the metadata or rejected with the error
*/
export function retrieveStudyMetadata(
dicomWebClient,
StudyInstanceUID,
enableStudyLazyLoad,
filters
) {
// @TODO: Whenever a study metadata request has failed, its related promise will be rejected once and for all
// and further requests for that metadata will always fail. On failure, we probably need to remove the
// corresponding promise from the "StudyMetaDataPromises" map...
if (!dicomWebClient) {
throw new Error(
`${moduleName}: Required 'dicomWebClient' parameter not provided.`
);
}
if (!StudyInstanceUID) {
throw new Error(
`${moduleName}: Required 'StudyInstanceUID' parameter not provided.`
);
}
// Already waiting on result? Return cached promise
if (StudyMetaDataPromises.has(StudyInstanceUID)) {
return StudyMetaDataPromises.get(StudyInstanceUID);
}
// Create a promise to handle the data retrieval
const promise = new Promise((resolve, reject) => {
RetrieveMetadata(
dicomWebClient,
StudyInstanceUID,
enableStudyLazyLoad,
filters
).then(function(data) {
resolve(data);
}, reject);
});
// Store the promise in cache
StudyMetaDataPromises.set(StudyInstanceUID, promise);
return promise;
}
/**
* Delete the cached study metadata retrieval promise to ensure that the browser will
* re-retrieve the study metadata when it is next requested
*
* @param {String} StudyInstanceUID The UID of the Study to be removed from cache
*
*/
export function deleteStudyMetadataPromise(StudyInstanceUID) {
if (StudyMetaDataPromises.has(StudyInstanceUID)) {
StudyMetaDataPromises.delete(StudyInstanceUID);
}
}