gol4ng/logger

package middleware

import (
    "github.com/gol4ng/logger"
)

// Context will define and merge defaultContext with each Entry Context
// if a default context key is redefined when calling Log/Debug/Info/... func, it will override the default ctx value
func Context(defaultContext *logger.Context) logger.MiddlewareInterface {
    return func(handler logger.HandlerInterface) logger.HandlerInterface {
        return func(entry logger.Entry) error {
            newCtx := logger.NewContext()
            // copy original context
            if defaultContext != nil {
                for name, field := range *defaultContext {
                    (*newCtx)[name] = field
                }
            }
            // merge original context with given context
            if entry.Context != nil {
                for name, field := range *entry.Context {
                    (*newCtx)[name] = field
                }
            }
            return handler(logger.Entry{
                Message: entry.Message,
                Level:   entry.Level,
                Context: newCtx,
            })
        }
    }
}