Context Binding

Context binding allows you to attach persistent key-value pairs to your logger. These values are automatically included in every log message, which is incredibly useful for tracking requests, users, or sessions.

Binding Values

You can bind strings, integers, booleans, and more.

// Bind a user ID
try logger.bind("user_id", .{ .string = "12345" });

// Bind a request ID
try logger.bind("request_id", .{ .string = "req-abc-123" });

// Bind a boolean flag
try logger.bind("is_admin", .{ .bool = true });

Unbinding Values

When a context is no longer needed (e.g., at the end of a request), you can unbind it.

logger.unbind("request_id");

Usage Example

fn handleRequest(logger: *logly.Logger, req: Request) !void {
    // Start of request
    try logger.bind("path", .{ .string = req.path });
    try logger.bind("method", .{ .string = req.method });

    try logger.info("Handling request", @src());

    // ... processing ...

    try logger.success("Request completed", @src());

    // Cleanup
    logger.unbind("path");
    logger.unbind("method");
}

JSON Output

When using JSON logging, context values are grouped under the context object.

{
  "message": "Handling request",
  "context": {
    "path": "/api/users",
    "method": "GET"
  }
}