"""
HTML logger inspired by the Horde3D logger.
Usage:
- call setup and specify the filename, title, version and level
- call dbg, info, warn or err to log messages.
"""
import logging
import time
#: HTML header (starts the document
_START_OF_DOC_FMT = """
%(title)s
%(title)s
%(version)s
"""
_END_OF_DOC_FMT = """
"""
_MSG_FMT = """
| %(time)s |
%(msg)s |
"""
class HTMLFileHandler(logging.FileHandler):
"""
File handler specialised to write the start of doc as html and to close it
properly.
"""
def __init__(self, title, version, *args):
super().__init__(*args)
assert self.stream is not None
# Write header
self.stream.write(_START_OF_DOC_FMT % {"title": title,
"version": version})
def close(self):
# finish document
self.stream.write(_END_OF_DOC_FMT)
super().close()
class HTMLFormatter(logging.Formatter):
"""
Formats each record in html
"""
CSS_CLASSES = {'WARNING': 'warn',
'INFO': 'info',
'DEBUG': 'debug',
'CRITICAL': 'err',
'ERROR': 'err'}
def __init__(self):
super().__init__()
self._start_time = time.time()
def format(self, record):
try:
class_name = self.CSS_CLASSES[record.levelname]
except KeyError:
class_name = "info"
t = time.time() - self._start_time
# handle '<' and '>' (typically when logging %r)
msg = record.msg
msg = msg.replace("<", "<")
msg = msg.replace(">", ">")
return _MSG_FMT % {"class": class_name, "time": "%.4f" % t,
"msg": msg}
class HTMLLogger(logging.Logger):
"""
Log records to html using a custom HTML formatter and a specialised
file stream handler.
"""
def __init__(self,
name="html_logger",
level=logging.DEBUG,
filename="log.html", mode='w',
title="HTML Logger", version="1.0.0"):
super().__init__(name, level)
f = HTMLFormatter()
h = HTMLFileHandler(title, version, filename, mode)
h.setFormatter(f)
self.addHandler(h)
#: Global logger instance
_logger = None
def setup(title, version, filename="log.html", mode='w', level=logging.DEBUG):
"""
Setup the logger
:param title: Title of the html document
:param version: Framework/lib/app version
:param filename: output filename. Default is "log.html"
:param mode: File open mode. Default is 'w'
:param level: handler output level. Default is DEBUG
"""
global _logger
if _logger is None:
_logger = HTMLLogger(filename=filename, mode=mode, title=title,
version=version, level=level)
def dbg(msg):
"""
Logs a debug message
"""
global _logger
_logger.debug(msg)
def info(msg):
"""
Logs an info message
"""
global _logger
_logger.info(msg)
def warn(msg):
"""
Logs a warning message
"""
global _logger
_logger.warning(msg)
def err(msg):
"""
Logs an error message
"""
global _logger
_logger.error(msg)
# Example of usage
if __name__ == "__main__":
setup("Example", "1.0")
dbg("A debug message")
info("An information message")
warn("A warning message")
time.sleep(1)
err("An error message")