Overview
This node interacts with FHIR (Fast Healthcare Interoperability Resources) servers to perform various operations on healthcare data resources. Specifically, the "History" operation retrieves the change history of a specified FHIR resource by its ID. This is useful for auditing, tracking changes over time, or understanding the evolution of patient records or other clinical data.
Common scenarios include:
- Auditing modifications made to a patient's record.
- Retrieving previous versions of a resource for compliance or review.
- Investigating the timeline of updates to clinical documents or observations.
For example, a user might want to get the full history of an "Observation" resource to see all updates and corrections made during a patient's treatment.
Properties
| Name | Meaning |
|---|---|
| Authentication | The method used to authenticate requests to the FHIR server. Options include Basic Auth, Custom Auth, Digest Auth, Header Auth, None, OAuth1, OAuth2, Query Auth. |
| Base URL | The base URL of the FHIR server API to which requests are sent. Required when using certain authentication methods. |
| Operation | The action to perform on the FHIR resource. For this context: "History" retrieves the version history of a resource. |
| Resource Type | The type of FHIR resource to operate on (e.g., Patient, Observation, MedicationRequest). A comprehensive list of standard FHIR resource types is provided, plus a custom option. |
| Custom Resource Type | If "Resource Type" is set to custom, this string specifies the custom resource type name. |
| Tenant ID | Optional tenant identifier included in request headers for multi-tenant FHIR servers. |
| ID | The unique identifier of the specific FHIR resource instance whose history is requested. Required for History operation. |
| Specify Query Parameters | How query parameters are specified: either as key-value pairs or as raw JSON. |
| Query Parameters | Key-value pairs of additional query parameters to include in the request URL. |
| JSON | Raw JSON string representing query parameters if specifying them as JSON. |
| FHIR Path | An optional FHIRPath expression to extract specific data from the response output. |
| Ignore SSL Issues | Whether to ignore SSL certificate validation errors when connecting to the FHIR server. Useful for self-signed certificates or development environments. |
Output
The node outputs an array of JSON objects representing the historical versions of the specified FHIR resource. Each item corresponds to one version entry from the resource's history.
- If the response is a FHIR Bundle, each entry's resource is extracted and output separately.
- If a FHIRPath expression is provided, it is applied to filter or transform the output data accordingly.
- The output includes paired item information linking back to the input item index.
- No binary data output is produced by this operation.
Dependencies
- Requires access to a FHIR server endpoint supporting the FHIR RESTful API, specifically the
_historyinteraction on resources. - Supports multiple authentication methods; users must configure appropriate credentials or tokens depending on the chosen authentication.
- Optionally requires tenant identification headers if the FHIR server uses multi-tenancy.
- Uses the
fhirpathlibrary internally to evaluate FHIRPath expressions on the response data.
Troubleshooting
- Invalid JSON in Query or Body: If JSON fields (like query parameters or patch bodies) are malformed, the node throws an error indicating invalid JSON. Ensure JSON syntax correctness.
- More Than One Result Error: When performing searches (not directly relevant to History), if configured to error on multiple results but multiple entries are returned, an error is thrown.
- SSL Certificate Errors: If connecting to a server with invalid or self-signed certificates, enable "Ignore SSL Issues" to bypass validation.
- Missing or Incorrect Resource ID: The History operation requires a valid resource ID; missing or incorrect IDs will cause request failures.
- Unsupported Operation: If an unsupported operation is selected, the node throws an error indicating the operation is not supported.
- Authentication Failures: Ensure that the correct authentication method and credentials are configured; otherwise, requests will be rejected by the FHIR server.