logger: Application log support

This module is very important.

class CollatingLog

Bases: chimera.core.logger.PlainTextLog

Collates log messages

This class is designed to be used when some operation may produce many log messages that would be more convenient to present as one combined message. You call the logger’s add_log() method to start collating, and remove it with remove_log() to stop collating. If the operation may produce many consecutive simiilar (or identical) log messagesm you may also want to set the logger’s collapse_similar attribute to True after adding the log, and set it back to its original value before removing the log.

To get the collated messages, call summarize() on the log. That will return a 2-tuple consisting of the maximum log level of the messages, and their combined text. The text will list the errors, warnings, etc. in separate sections of the text. To log the result, use the logger’s method_map dictionary to convert the maximum level to a method to call, and call that method with the summary as an argument (possibly preceded with some introductory text) and with the add_newline keyword set to False.

class Collator(logger, summary_title, log_errors=True)

Bases: object

Context manager for a CollatingLog

Parameters:

logger : the session’s Logger

The logger to use.

summary_title : string

What to title the log summary.

log_errors : boolean

Whether or not to log errors, defaults True.

class HtmlLog

Bases: chimera.core.logger.Log

Base class for logs that support HTML output

log(level, msg, image_info, is_html)

Log a message.

Parameters:

level : LEVEL_XXX constant from Log base class

How important the message is (e.g., error, warning, info)

msg : text, possibly HTML

Message to log

image_info : a (image, boolean) 2-tuple

image is either a PIL image or None (if there is no image to log). The boolean indicates whether there should be a line break after the image. When there is an image to log, msg param is alt text to use

is_html : boolean

Is the message text HTML or not

Returns:

True if the routine displayed/handled the log message, False otherwise.

class Log

Bases: object

Base class for the “real” log classes: HtmlLog and PlainTextLog.

Attributes

LEVEL_ERROR (for error messages)
LEVEL_INFO (for informational messages)
LEVEL_WARNING (for warning messages)
log(level, msg)

Log a message.

Must be overriden by subclass.

Parameters:

level : LEVEL_XXX constant from Log base class

How important the message is (e.g., error, warning, info)

msg : text, possibly HTML

Message to log

status(msg, color, secondary)

Show a status message.

Parameters:

msg : plain (non-HTML) text

The message to display

color : text or (r,g,b) tuple, r/g/b in range 0-1

Color to display text in. If log cannot understand color text string, use black instead.

secondary : boolean

Whether to show the status in the secondary status area. If the log doesn’t support a secondary status area it should either drop the status or combine it with the last known primary status message.

Returns:

True if the routine displayed/handled the status, False otherwise.

This method is not abstract because a log is free to totally

ignore/drop status messages.

Note that this method may be called from a thread (due to the

use of timers to get proper time delays) and that therefore

special window toolkit handling may be necessary to get your

code executed in the main thread (e.g., wx.CallAfter).

class Logger(session)

Bases: object

Log/status message dispatcher

Log/status message producers use the error()/ warning()/ info()/ status() methods to send messages to a log. The message will be sent to the log at the top of the log stack and then each other log in order.

Message consumers must inherit from HtmlLog or PlainTextLog and register themselves with the Logger’s add_log() method, which will put them at the top of the log stack. When quitting or otherwise no longer interested in receiving log messages they should deregister themselves with the remove_log() method. Consumers need to override their Log.log() abstract method, but need not override the Log.status() method if they are not interested in showing status.

If the Logger collapse_similar attribute is True, then after a few occurances of consecutive similar log messages, the remainder will be collapsed into a single log message noting how many additional occurances there were.

add_log(log)

Add a logger

clear()

clear all loggers

error(msg, add_newline=True, image=None, is_html=False)

Log an error message

Parameters:

msg : text

Message to log, either plain text or HTML

add_newline : boolean

Whether to add a newline to the message before logging it (also whether there is a line break after an image)

image : PIL image or None

If not None, an image to log. If an image is provided, then the :param:msg parameter is alt text to show for logs than cannot display images

is_html : boolean

Is the :param:msg text HTML or plain text

info(msg, add_newline=True, image=None, is_html=False)

Log an info message

The parameters are the same as for the error() method.

remove_log(log)

remove a logger

status(msg, color='black', log=False, secondary=False, blank_after=None, follow_with='', follow_time=20, follow_log=None)

Show status.

warning(msg, add_newline=True, image=None, is_html=False)

Log a warning message

The parameters are the same as for the error() method.

class PlainTextLog

Bases: chimera.core.logger.Log

Base class for logs that support only plain text output

log(level, msg)

Log a message.

Parameters:

level : LOG_XXX constant from Log base class

How important the message is (e.g., error, warning, info)

msg : text

Message to log

Returns:

True if the routine displayed/handled the log message, False otherwise.

html_to_plain(html)

‘best effort’ to convert HTML to plain text