def check_timestamps(self, bundle, ctx, o_modified=None):
from .bundle import Bundle
from webassets.version import TimestampVersion
if not o_modified:
try:
resolved_output = bundle.resolve_output(ctx)
except BundleError:
# This exception will occur when the bundle output has
# placeholder, but a version cannot be found. If the
# user has defined a manifest, this will just be the first
# build. Return True to let it happen.
# However, if no manifest is defined, raise an error,
# because otherwise, this updater would always return True,
# and thus not do its job at all.
if ctx.manifest is None:
raise BuildError(
('%s uses a version placeholder, and you are '
'using "%s" versions. To use automatic '
'building in this configuration, you need to '
'define a manifest.' % (bundle, ctx.versions)))
return True
try:
o_modified = TimestampVersion.get_timestamp(resolved_output)
except OSError:
# If the output file does not exist, we'll have to rebuild
return True
# Recurse through the bundle hierarchy. Check the timestamp of all
# the bundle source files, as well as any additional
# dependencies that we are supposed to watch.
from webassets.bundle import wrap
for iterator, result in (
(lambda e: map(lambda s: s[1], bundle.resolve_contents(e)),
True), (bundle.resolve_depends, SKIP_CACHE)):
for item in iterator(ctx):
if isinstance(item, Bundle):
nested_result = self.check_timestamps(
item, wrap(ctx, item), o_modified)
if nested_result:
return nested_result
elif not is_url(item):
try:
s_modified = TimestampVersion.get_timestamp(item)
except OSError:
# If a file goes missing, always require
# a rebuild.
return result
else:
if s_modified > o_modified:
return result
return False
def failing_filter(*a, **kw):
raise BuildError()