# -*- coding: utf-8 -*-
#
# This file is part of Invenio.
# Copyright (C) 2016 CERN.
#
# Invenio 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 2 of the
# License, or (at your option) any later version.
#
# Invenio 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 Invenio; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
# MA 02111-1307, USA.
#
# In applying this license, CERN does not
# waive the privileges and immunities granted to it by virtue of its status
# as an Intergovernmental Organization or submit itself to any jurisdiction.
"""Invenio module for previewing files."""
from __future__ import absolute_import, print_function
import pkg_resources
import six
from flask import current_app
from pkg_resources import DistributionNotFound, get_distribution
from werkzeug.utils import cached_property, import_string
from . import config
from .views import blueprint
[docs]def obj_or_import_string(value, default=None):
"""Import string or return object."""
if isinstance(value, six.string_types):
return import_string(value)
elif value:
return value
return default
[docs]def load_or_import_from_config(key, app=None, default=None):
"""Load or import value from config."""
app = app or current_app
imp = app.config.get(key)
return obj_or_import_string(imp, default=default)
class _InvenioPreviewerState(object):
"""State object."""
def __init__(self, app, entry_point_group=None):
"""Initialize state."""
self.app = app
self.entry_point_group = entry_point_group
self.previewers = {}
self._previewable_extensions = set()
@cached_property
def previewable_extensions(self):
if self.entry_point_group is not None:
self.load_entry_point_group(self.entry_point_group)
self.entry_point_group = None
return self._previewable_extensions
@cached_property
def record_file_factory(self):
"""Load default record file factory."""
try:
get_distribution('invenio-records-files')
from invenio_records_files.utils import record_file_factory
default = record_file_factory
except DistributionNotFound:
def default(pid, record, filename):
return None
return load_or_import_from_config(
'PREVIEWER_RECORD_FILE_FACOTRY',
app=self.app,
default=default,
)
@property
def css_bundles(self):
return self.app.config['PREVIEWER_BASE_CSS_BUNDLES']
@property
def js_bundles(self):
return self.app.config['PREVIEWER_BASE_JS_BUNDLES']
def register_previewer(self, name, previewer):
"""Register a previewer in the system."""
if name in self.previewers:
assert name not in self.previewers, \
"Previewer with same name already registered"
self.previewers[name] = previewer
if hasattr(previewer, 'previewable_extensions'):
self._previewable_extensions |= set(
previewer.previewable_extensions)
def load_entry_point_group(self, entry_point_group):
"""Load previewers from an entry point group."""
for ep in pkg_resources.iter_entry_points(group=entry_point_group):
self.register_previewer(ep.name, ep.load())
def iter_previewers(self, previewers=None):
"""Get previewers ordered by PREVIEWER_PREVIEWERS_ORDER."""
if self.entry_point_group is not None:
self.load_entry_point_group(self.entry_point_group)
self.entry_point_group = None
previewers = previewers or \
self.app.config.get('PREVIEWER_PREFERENCE', [])
for item in previewers:
if item in self.previewers:
yield self.previewers[item]
[docs]class InvenioPreviewer(object):
"""Invenio-Previewer extension."""
def __init__(self, app, **kwargs):
"""Extension initialization."""
if app:
self._state = self.init_app(app, **kwargs)
[docs] def init_app(self, app, entry_point_group='invenio_previewer.previewers'):
"""Flask application initialization."""
self.init_config(app)
app.register_blueprint(blueprint)
state = _InvenioPreviewerState(
app,
entry_point_group=entry_point_group)
app.extensions['invenio-previewer'] = state
return state
[docs] def init_config(self, app):
"""Initialize configuration."""
app.config.setdefault(
'PREVIEWER_BASE_TEMPLATE', 'invenio_previewer/base.html')
for k in dir(config):
if k.startswith('PREVIEWER_'):
app.config.setdefault(k, getattr(config, k))
def __getattr__(self, name):
"""Proxy to state object."""
return getattr(self._state, name, None)
