osmo-gsm-tester/src/osmo_gsm_tester/template.py

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# osmo_gsm_tester: automated cellular network hardware tests
# Proxy to templating engine to handle files
#
# Copyright (C) 2016-2017 by sysmocom - s.f.m.c. GmbH
#
# Author: Neels Hofmeyr <neels@hofmeyr.de>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import os
from mako.lookup import TemplateLookup, Template
from . import log
from .util import dict2obj
_lookup = None
fix and refactor logging: drop 'with', simplify With the recent fix of the junit report related issues, another issue arose: the 'with log.Origin' was changed to disallow __enter__ing an object twice to fix problems, now still code would fail because it tries to do 'with' on the same object twice. The only reason is to ensure that logging is associated with a given object. Instead of complicating even more, implement differently. Refactor logging to simplify use: drop the 'with Origin' style completely, and instead use the python stack to determine which objects are created by which, and which object to associate a log statement with. The new way: we rely on the convention that each class instance has a local 'self' referencing the object instance. If we need to find an origin as a new object's parent, or to associate a log message with, we traverse each stack frame, fetching the first local 'self' object that is a log.Origin class instance. How to use: Simply call log.log() anywhere, and it finds an Origin object to log for, from the stack. Alternatively call self.log() for any Origin() object to skip the lookup. Create classes as child class of log.Origin and make sure to call super().__init__(category, name). This constructor will magically find a parent Origin on the stack. When an exception happens, we first escalate the exception up through call scopes to where ever it is handled by log.log_exn(). This then finds an Origin object in the traceback's stack frames, no need to nest in 'with' scopes. Hence the 'with log.Origin' now "happens implicitly", we can write pure natural python code, no more hassles with scope ordering. Furthermore, any frame can place additional logging information in a frame by calling log.ctx(). This is automatically inserted in the ancestry associated with a log statement / exception. Change-Id: I5f9b53150f2bb6fa9d63ce27f0806f0ca6a45e90
2017-06-09 23:18:27 +00:00
_logger = log.Origin(log.C_CNF, 'no templates dir set')
def set_templates_dir(*templates_dirs):
global _lookup
global _logger
if not templates_dirs:
# default templates dir is relative to this source file
templates_dirs = [os.path.join(os.path.dirname(__file__), 'templates')]
for d in templates_dirs:
if not os.path.isdir(d):
raise RuntimeError('templates dir is not a dir: %r'
% os.path.abspath(d))
_lookup = TemplateLookup(directories=templates_dirs)
fix and refactor logging: drop 'with', simplify With the recent fix of the junit report related issues, another issue arose: the 'with log.Origin' was changed to disallow __enter__ing an object twice to fix problems, now still code would fail because it tries to do 'with' on the same object twice. The only reason is to ensure that logging is associated with a given object. Instead of complicating even more, implement differently. Refactor logging to simplify use: drop the 'with Origin' style completely, and instead use the python stack to determine which objects are created by which, and which object to associate a log statement with. The new way: we rely on the convention that each class instance has a local 'self' referencing the object instance. If we need to find an origin as a new object's parent, or to associate a log message with, we traverse each stack frame, fetching the first local 'self' object that is a log.Origin class instance. How to use: Simply call log.log() anywhere, and it finds an Origin object to log for, from the stack. Alternatively call self.log() for any Origin() object to skip the lookup. Create classes as child class of log.Origin and make sure to call super().__init__(category, name). This constructor will magically find a parent Origin on the stack. When an exception happens, we first escalate the exception up through call scopes to where ever it is handled by log.log_exn(). This then finds an Origin object in the traceback's stack frames, no need to nest in 'with' scopes. Hence the 'with log.Origin' now "happens implicitly", we can write pure natural python code, no more hassles with scope ordering. Furthermore, any frame can place additional logging information in a frame by calling log.ctx(). This is automatically inserted in the ancestry associated with a log statement / exception. Change-Id: I5f9b53150f2bb6fa9d63ce27f0806f0ca6a45e90
2017-06-09 23:18:27 +00:00
_logger = log.Origin(log.C_CNF, 'Templates')
def render(name, values):
'''feed values dict into template and return rendered result.
".tmpl" is added to the name to look it up in the templates dir.'''
global _lookup
if _lookup is None:
set_templates_dir()
tmpl_name = name + '.tmpl'
fix and refactor logging: drop 'with', simplify With the recent fix of the junit report related issues, another issue arose: the 'with log.Origin' was changed to disallow __enter__ing an object twice to fix problems, now still code would fail because it tries to do 'with' on the same object twice. The only reason is to ensure that logging is associated with a given object. Instead of complicating even more, implement differently. Refactor logging to simplify use: drop the 'with Origin' style completely, and instead use the python stack to determine which objects are created by which, and which object to associate a log statement with. The new way: we rely on the convention that each class instance has a local 'self' referencing the object instance. If we need to find an origin as a new object's parent, or to associate a log message with, we traverse each stack frame, fetching the first local 'self' object that is a log.Origin class instance. How to use: Simply call log.log() anywhere, and it finds an Origin object to log for, from the stack. Alternatively call self.log() for any Origin() object to skip the lookup. Create classes as child class of log.Origin and make sure to call super().__init__(category, name). This constructor will magically find a parent Origin on the stack. When an exception happens, we first escalate the exception up through call scopes to where ever it is handled by log.log_exn(). This then finds an Origin object in the traceback's stack frames, no need to nest in 'with' scopes. Hence the 'with log.Origin' now "happens implicitly", we can write pure natural python code, no more hassles with scope ordering. Furthermore, any frame can place additional logging information in a frame by calling log.ctx(). This is automatically inserted in the ancestry associated with a log statement / exception. Change-Id: I5f9b53150f2bb6fa9d63ce27f0806f0ca6a45e90
2017-06-09 23:18:27 +00:00
log.ctx(tmpl_name)
template = _lookup.get_template(tmpl_name)
_logger.dbg('rendering', tmpl_name)
fix and refactor logging: drop 'with', simplify With the recent fix of the junit report related issues, another issue arose: the 'with log.Origin' was changed to disallow __enter__ing an object twice to fix problems, now still code would fail because it tries to do 'with' on the same object twice. The only reason is to ensure that logging is associated with a given object. Instead of complicating even more, implement differently. Refactor logging to simplify use: drop the 'with Origin' style completely, and instead use the python stack to determine which objects are created by which, and which object to associate a log statement with. The new way: we rely on the convention that each class instance has a local 'self' referencing the object instance. If we need to find an origin as a new object's parent, or to associate a log message with, we traverse each stack frame, fetching the first local 'self' object that is a log.Origin class instance. How to use: Simply call log.log() anywhere, and it finds an Origin object to log for, from the stack. Alternatively call self.log() for any Origin() object to skip the lookup. Create classes as child class of log.Origin and make sure to call super().__init__(category, name). This constructor will magically find a parent Origin on the stack. When an exception happens, we first escalate the exception up through call scopes to where ever it is handled by log.log_exn(). This then finds an Origin object in the traceback's stack frames, no need to nest in 'with' scopes. Hence the 'with log.Origin' now "happens implicitly", we can write pure natural python code, no more hassles with scope ordering. Furthermore, any frame can place additional logging information in a frame by calling log.ctx(). This is automatically inserted in the ancestry associated with a log statement / exception. Change-Id: I5f9b53150f2bb6fa9d63ce27f0806f0ca6a45e90
2017-06-09 23:18:27 +00:00
return template.render(**dict2obj(values))
def render_strbuf_inline(strbuf, values):
'''Receive a string containing template syntax, and generate output using
passed values.'''
mytemplate = Template(strbuf)
return mytemplate.render(**dict2obj(values))
# vim: expandtab tabstop=4 shiftwidth=4