gol4ng/logger

package middleware

import (
    "strings"

    "github.com/gol4ng/logger"
)

// Placeholder will replace message placeholder with context field
func Placeholder() logger.MiddlewareInterface {
    return func(handler logger.HandlerInterface) logger.HandlerInterface {
        return func(entry logger.Entry) error {
            if entry.Context != nil && strings.Contains(entry.Message, "%") {
                msg := entry.Message
                for n, f := range *entry.Context {
                    msg = strings.Replace(msg, "%"+n+"%", f.String(), -1)
                    if !strings.Contains(msg, "%") {
                        break
                    }
                }
                entry.Message = msg
            }
            return handler(entry)
        }
    }
}