LogLayer

Default Context Manager ​

NPM VersionNPM DownloadsTypeScript

Context Manager Source

The Default Context Manager is the base context manager used by LogLayer. It provides a simple key-value store for managing context data with independent context for each logger instance.

INFO

This context manager is automatically used when creating a new LogLayer instance. You should not need to use this context manager directly.

Installation ​

This package is included with the loglayer package, so you don't need to install it separately.

It is, however, available as a standalone package:

bash
npm install @loglayer/context-manager
bash
yarn add @loglayer/context-manager
bash
pnpm add @loglayer/context-manager

Usage ​

Basic Usage ​

typescript
import { LogLayer, ConsoleTransport } from "loglayer";
import { DefaultContextManager } from "@loglayer/context-manager";

const logger = new LogLayer({
  transport: new ConsoleTransport({
    logger: console
  })
  // NOTE: This is redundant and unnecessary since DefaultContextManager is already 
  // the default context manager when LogLayer is created.
}).withContextManager(new DefaultContextManager());

// Set context
logger.setContext({
  requestId: "123",
  userId: "456"
});

// Log with context
logger.info("User action"); // Will include requestId and userId in the log entry

Child Loggers ​

When creating child loggers, the Default Context Manager will:

  1. Copy the parent's context to the child logger at creation time
  2. Maintain independent context after creation
typescript
parentLogger.setContext({ requestId: "123" });

const childLogger = parentLogger.child();
// Child inherits parent's context at creation via shallow-copy
childLogger.info("Initial log"); // Includes requestId: "123"

// Child can modify its context independently
childLogger.appendContext({ userId: "456" });
childLogger.info("User action"); // Includes requestId: "123" and userId: "456"

// Parent's context remains unchanged
parentLogger.info("Parent log"); // Only includes requestId: "123"