---
title: Resolve the most-recent external injured-worker user for a customer group
summary: GetInjuredWorkerUserByCustomerId end-to-end process on SAIF.Services.WCF.Services.Security.SecurityService.
status: draft
owner: SAIF Doc Gen
last_reviewed: 2026-09-22
operation_id: OP-023
trigger: Caller invokes `GetInjuredWorkerUserByCustomerId` over the `Security` route.
---

# OP-023: Resolve the most-recent external injured-worker user for a customer group

GetInjuredWorkerUserByCustomerId is invoked over the `Security` route on `SAIF.Services.WCF.Services.Security.SecurityService`; this page documents the process end to end, from route dispatch to the message the caller receives.

| Field | Value |
| --- | --- |
| **Operation ID** | OP-023 |
| **Trigger** | Caller invokes `GetInjuredWorkerUserByCustomerId` over the `Security` route. |
| **Entry operation** | [`GetInjuredWorkerUserByCustomerId`](../contracts/security-service.md#getinjuredworkeruserbycustomerid) |
| **Owning component** | `SAIF.Services.WCF.Services.Security.SecurityService.GetInjuredWorkerUserByCustomerId` |
| **Inputs** | Request message parts listed below |
| **Outputs** | An `ExternalUser` projection for the most-recently-logged-in matching injured-worker user. |
| **Failure behavior** | Generic SOAP fault, per [Faults and error pipeline](../faults.md) |

## Request and response

| Direction | Element | Type | Declared in | Notes |
| --- | --- | --- | --- | --- |
| Request | `customerId` | `string` | BCL (`System`) | Customer group identifier used to locate the most-recently-logged-in injured-worker user. (Yes) |
| Response | `ExternalUser` | `ExternalUser` | External contracts assembly (`SAIF.Services.WCF.Contracts` / framework closure) ** | An `ExternalUser` projection for the most-recently-logged-in matching injured-worker user. |

<!-- Types declared in `SAIF.Services.WCF.Contracts` are attributed to `SAIF.Framework.Core`, inferred from source and package references and marked `*`; their members are not enumerated because the external declaration was not read, marked `**`. -->

## Steps

1. `LogRequestDetails` logs the operation name and arguments ([BR-WCF-032](../business-rules.md#br-wcf-032-every-security-operation-logs-its-request)).
2. `GetCustomerUserId` runs with the user-type codes fixed to `WORK`, `GUARD`, `POWA`, joining `ExternalUser` to its `UserTypes`, filtering by `CustomerGroupId`, ordering by `LastLogonDate` descending, and taking the first user id ([BR-WCF-034](../business-rules.md#br-wcf-034-customer-id-resolves-to-the-most-recent-user)); a null user id returns `null`.
3. Otherwise the resolved user id runs through the same `TryGetExternalUser` projection used by `GetExternalUser` ([BR-WCF-019a](../business-rules.md#br-wcf-019a-external-user-active-and-locked-state-derived-from-one-flag), [BR-WCF-020a](../business-rules.md#br-wcf-020a-injured-worker-status-from-primary-user-type-code), [BR-WCF-021a](../business-rules.md#br-wcf-021a-primary-contact-selection-rules)).
4. Return.
   - On failure: an Oracle/NHibernate exception is logged by the installed error handler and surfaced as a generic SOAP fault with exception detail included.

## Process flow

The following diagram visualizes this process's control flow.

```mermaid
flowchart TD
    A["Log request details"]
    B["Resolve most-recent injured-worker<br>user id for customer"]
    B1{"User id resolved?"}
    B2["Null user id: return null"]
    C["Project user via TryGetExternalUser"]
    D["Return."]
    A --> B
    B --> B1
    B1 -->|"No"| B2
    B1 -->|"Yes"| C
    B2 --> D
    C --> D
```

## Transaction and side effects

| Aspect | Finding |
| --- | --- |
| Unit of work | `OracleUnitOfWorkFactory` (`EXTUR`) |
| Commit point | Not applicable — read only |
| Records written | `ExternalUser`, `ExternalUserType`, `Person`, `Address`, `Phone` (read only) |
| Downstream calls | None |
| Shared state touched | None |
| Repeat-call behavior | Idempotent read; result can change as `LastLogonDate` values change |

## Logging

| Surface | Written content |
| --- | --- |
| `HttpContext.Current.Response.AppendToLog` (`LogRequestDetails`) | Writes IIS request-detail log lines when `LOG_REQUEST_DETAILS` is enabled |
| `ErrorLogErrorHandler` → `LogService` | Failure-path exception logging only, carrying method signature, calling user and exception detail; see [Faults and error pipeline](../faults.md) |

## Faults and error handling

| Failure | Fault type the caller receives | Produced by | Source |
| --- | --- | --- | --- |
| Oracle/NHibernate exception | `Generic SOAP fault` | The `ErrorLogErrorHandler` installed by `[LogErrorBehavior]` | src/WCF/SAIF.Services.WCF.Host/Services/Security/Users/UserFactory.cs |

## Authorization

| Requirement | Enforced by | Source | Applies to |
| --- | --- | --- | --- |
| [None in code](../authentication-authorization.md#authorization-enforcement) | IIS authentication on the deployment (see [Activation and hosting](../activation-hosting.md)) | `src/WCF/SAIF.Services.WCF.Host/Services/Security/SecurityService.cs` | This operation |

## Related documentation
- [Index](../index.md)
- [Overview](../overview.md)
- [Architecture](../architecture.md)
- [Activation and hosting](../activation-hosting.md)
- [Operations](../operations.md)
- [Faults and error pipeline](../faults.md)
- [Authentication and authorization](../authentication-authorization.md)
- [Dependencies](../dependencies.md)
- [Configuration](../configuration.md)
- [Operations and processes](../operations-processes.md)
- [Business rules](../business-rules.md)
- [Data model](../data-model.md)
- [Operational runbook](../operational-runbook.md)
- [Tech debt](../tech-debt.md)

> **Note:** Statements marked with `*` were inferred from code structure, naming
> conventions, or contextual evidence where direct confirmation was not available
> in source artifacts. Statements marked with `**` could not be confirmed; treat
> as unknown until verified.

## Sources
- src/WCF/SAIF.Services.WCF.Host/Services/Security/SecurityService.cs
- src/WCF/SAIF.Services.WCF.Host/Services/Security/Users/UserFactory.cs