---
title: Write contextual diagnostic log entry
summary: Format and emit a request-aware log4net message for the authentication pipeline.
status: draft
owner: SAIF Documentation Team
last_reviewed: 2026-07-30
library: SAIF.Framework.SecurityModule
reference_type: package
operation_id: write-contextual-diagnostic-log-entry
trigger: Library code calls LogInfo, LogWarn, LogError, or LogDebug.
---

# Write contextual diagnostic log entry

This operation centralizes diagnostic logging for the library. Every log call routes through it, ensuring each message reaches log4net carrying the current host address, request URL, application name, and a reduced call-stack trail — so authentication activity can be reconstructed from the logs even though the individual authenticator classes never format their own log entries.

| Field | Value |
| --- | --- |
| **Operation ID** | `write-contextual-diagnostic-log-entry` |
| **Trigger** | Library code calls `LogInfo`, `LogWarn`, `LogError`, or `LogDebug`. |
| **Inputs** | Message text, current `HttpContext`, current stack trace |
| **Outputs** | Formatted log4net entry |
| **Primary components** | `mdlLogging.LogInfo`, `mdlLogging.LogWarn`, `mdlLogging.LogError`, `mdlLogging.LogDebug`, `mdlLogging.LogMsg` |
| **Entry point** | `SAIF.Framework.SecurityModule\mdlLogging.vb` |

## Steps

1. On first use, lazily initialize `m_log` by calling `LogManager.GetLogger(GetType(clsSecurityModule).Name)`, so the logger is created once per application lifetime rather than on every call.
2. Route the severity-specific helper the caller invoked (`LogInfo`, `LogWarn`, `LogError`, or `LogDebug`) through `LogMsg`, passing the matching log4net formatter delegate.
3. Inside `LogMsg`, read the application path, host address, and request URL from `HttpContext.Current.Request`.
4. Build a call-stack summary by scanning `StackTrace.GetFrames()`: keep only frames declared on `clsSecurityModule`, skip helper-frame names beginning with `ASSERT` or `GETSTACKFRAMES`, reverse the remaining sequence so it reads outer-to-inner, and join the method names with `->`.
5. Format the final message as `{hostAddress},{requestUrl},{applicationName}->{stackFrames},{message}` and invoke the requested log4net delegate with that string.

## Process flow

The following diagram visualizes this operation's control flow.

```mermaid
flowchart TD
	Start([Logging helper called]) --> S1[Get or create logger]
	S1 --> S2[Collect request context]
	S2 --> S3[Derive stack-frame trail]
	S3 --> S4[Format combined message]
	S4 --> EndOk([Write log4net entry])
```

## Failure and edge-case behavior

- The operation assumes `HttpContext.Current` and `HttpContext.Current.Request` are available whenever logging is invoked; it does not guard against a null ambient context.
- The reduced stack trace includes only frames declared on `clsSecurityModule`, so it does not show intermediate frames when a log call originates from other helper classes in the call chain.

## Related documentation
- [Operations and processes](../operations-processes.md)
- [Business rules](../business-rules.md)
- [Configuration](../configuration.md)

## Sources
- `SAIF.Framework.SecurityModule\mdlLogging.vb`