Overview
This node, named "bonFHIR," is designed to interact with FHIR (Fast Healthcare Interoperability Resources) servers by performing various operations on FHIR resources. Specifically, the "History" operation retrieves the change history of a specified FHIR resource instance. This can be useful in healthcare scenarios where tracking the evolution of patient data or other clinical information over time is necessary.
Common use cases include:
- Auditing changes made to a patient's record.
- Retrieving previous versions of a resource for compliance or analysis.
- Monitoring updates to clinical documents or observations.
For example, a user might want to fetch the entire history of an "Observation" resource to see all modifications 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 will be sent. |
| Resource Type | The type of FHIR resource to operate on (e.g., Patient, Observation, Encounter). A comprehensive list of standard FHIR resource types is provided, plus an option for custom resource types. |
| Custom Resource Type | If "Resource Type" is set to custom, this string specifies the custom resource type name. |
| ID | The unique identifier of the specific resource instance whose history is to be retrieved. Required for operations like History, Read, Update, Delete, Patch, VRead. |
| Specify Query Parameters | How query parameters are specified: either as key-value pairs or as a JSON object. |
| Query Parameters | Key-value pairs representing additional query parameters to include in the request URL. |
| JSON | A JSON object specifying query parameters when "Specify Query Parameters" is set to JSON. |
| FHIR Path | An optional FHIRPath expression to extract specific data from the response output. |
| Ignore SSL Issues | Whether to allow connections even if SSL certificate validation fails (useful for self-signed certificates). |
Additional properties related to other operations (like Patch parameters, version ID for VRead, etc.) exist but are not relevant for the "History" operation.
Output
The node outputs the raw JSON response from the FHIR server corresponding to the requested operation. For the "History" operation, this typically includes a FHIR Bundle resource containing the historical versions of the specified resource.
If a FHIRPath expression is provided, the node evaluates it against the response and outputs the extracted data instead of the full response.
The output structure is an array of items, each with a json field containing the resource or extracted data, and a pairedItem indicating the input item index.
Binary data is not produced by this node.
Dependencies
- Requires access to a FHIR server endpoint specified by the "Base URL."
- Supports multiple authentication methods; appropriate credentials or tokens must be configured in n8n.
- Uses internal utilities for HTTP requests with authentication handling.
- Optionally uses a FHIRPath evaluation library to process responses if a FHIRPath expression is provided.
No external environment variables beyond standard n8n credential configurations are required.
Troubleshooting
- Invalid Base URL or Network Errors: Ensure the "Base URL" is correct and accessible from the n8n instance. Use "Ignore SSL Issues" cautiously if connecting to servers with self-signed certificates.
- Authentication Failures: Verify that the selected authentication method matches the FHIR server's requirements and that credentials are correctly configured.
- Resource Not Found: If the specified resource ID does not exist, the FHIR server will return an error. Confirm the resource type and ID are correct.
- Multiple Results Error: When using the "Search" operation with "Error if More than One Result" enabled, the node throws an error if more than one resource is returned. For "History," this is not applicable.
- Malformed Query Parameters: When specifying query parameters as JSON, ensure valid JSON syntax; otherwise, the node will throw a parameter error.
- FHIRPath Evaluation Errors: Invalid FHIRPath expressions may cause evaluation errors. Validate expressions before use.
Links and References
- FHIR Specification - History Operation
- FHIRPath Specification
- UCUM Units of Measure
- n8n Documentation - Creating Custom Nodes
This summary is based solely on static analysis of the provided source code and property definitions without executing any code.