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extensions.py
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# -*- coding: utf-8 -*-
## This file is part of Invenio.
## Copyright (C) 2012, 2013 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.
"""
invenio.ext.assets.extensions
-----------------------------
This module contains custom `Jinja2` extensions.
"""
from operator import itemgetter
from jinja2 import nodes
from jinja2.ext import Extension
ENV_PREFIX = '_collected_'
def prepare_tag_bundle(cls, tag):
"""
Construct function that returns collected data specified
in jinja2 template like `{% <tag> <value> %}` in correct
order.
Here is an example that shows the final order when template
inheritance is used::
example.html
------------
{%\ extends 'page.html' %}
{%\ css 'template2.css' %}
{%\ css 'template3.css' %}
page.html
---------
{%\ css 'template1.css' %}
{{ get_css_bundle() }}
Output:
-------
[template1.css, template2.css, template3.css]
"""
def get_bundle(key=None, iterate=False):
def _get_data_by_key(data_, key_):
return map(itemgetter(1), filter(lambda (k, v): k == key_, data_))
data = getattr(cls.environment, ENV_PREFIX+tag)
if iterate:
bundles = sorted(set(map(itemgetter(0), data)))
def _generate_bundles():
for bundle in bundles:
cls._reset(tag, bundle)
yield cls.environment.new_bundle(tag,
_get_data_by_key(data,
bundle),
bundle)
return _generate_bundles()
else:
if key is not None:
data = _get_data_by_key(data, key)
else:
bundles = sorted(set(map(itemgetter(0), data)))
data = [f for bundle in bundles
for f in _get_data_by_key(data, bundle)]
cls._reset(tag, key)
return cls.environment.new_bundle(tag, data, key)
return get_bundle
class CollectionExtension(Extension):
"""
CollectionExtension adds new tags `css` and `js` and functions
``get_css_bundle`` and ``get_js_bundle`` for jinja2 templates.
The ``new_bundle`` method is used to create bundle from
list of file names collected using `css` and `js` tags.
Example: simple case
{% css 'css/invenio.css' %}
{% js 'js/jquery.js' %}
{% js 'js/invenio.js' %}
...
{% assets get_css_bundle() %}
<link rel="stylesheet" type="text/css" href="{{ ASSET_URL }}"></link>
{% endassets %}
{% assets get_js_bundle() %}
In template, use {{ ASSETS_URL }} for printing file URL.
{% endassets %}
Example: named bundles
record.html:
{% extend 'page.html' %}
{% css 'css/may-vary.css' %}
# default bundle name can be changed in application factory
# app.jinja_env.extend(default_bundle_name='90-default')
{% css 'css/record.css', '10-record' %}
{% css 'css/form.css', '10-record' %}
page.html:
{% css 'css/bootstrap.css', '00-base' %}
{% css 'css/invenio.css', '00-base' %}
...
{% for bundle in get_css_bundle(iterate=True) %}
{% assets bundle %}
<link rel="stylesheet" type="text/css" href="{{ ASSET_URL }}"></link>
{% endassets %}
{% endfor %}
Output:
<link rel="stylesheet" type="text/css" href="/css/00-base.css"></link>
<link rel="stylesheet" type="text/css" href="/css/10-record.css"></link>
<link rel="stylesheet" type="text/css" href="/css/90-default.css"></link>
Note:
If you decide not to use assets bundle but directly print
stylesheet and script html tags, you MUST define:
```
_app.jinja_env.extend(
use_bundle = False,
collection_templates = {
'css': '<link rel="stylesheet" type="text/css" href="/%s"></link>',
'js': '<script type="text/javascript" src="/%s"></script>'
})
```
Both callable and string with '%s' are allowed in
``collection_templates``.
"""
tags = set(['css', 'js'])
def __init__(self, environment):
super(CollectionExtension, self).__init__(environment)
ext = dict(('get_%s_bundle' % tag, prepare_tag_bundle(self, tag))
for tag in self.tags)
environment.extend(
default_bundle_name='10-default',
use_bundle=True,
collection_templates=dict((tag, lambda x: x) for tag in self.tags),
new_bundle=lambda tag, collection, name: collection,
**ext)
for tag in self.tags:
self._reset(tag)
def _reset(self, tag, key=None):
"""
Empty list of used scripts.
"""
if key is None:
setattr(self.environment, ENV_PREFIX+tag, [])
else:
data = filter(lambda (k, v): k != key,
getattr(self.environment, ENV_PREFIX+tag))
setattr(self.environment, ENV_PREFIX+tag, data)
def _update(self, tag, value, key, caller=None):
"""
Update list of used scripts.
"""
try:
values = getattr(self.environment, ENV_PREFIX+tag)
values.append((key, value))
except:
values = [(key, value)]
setattr(self.environment, ENV_PREFIX+tag, values)
return ''
def parse(self, parser):
"""
Parse Jinja statement tag defined in `self.tags` (default: css, js).
This accually tries to build corresponding html script tag
or collect script file name in jinja2 environment variable.
If you use bundles it is important to call ``get_css_bundle``
or ``get_js_bundle`` in template after all occurrences of
script tags (e.g. {% css ... %}, {% js ...%}).
"""
tag = parser.stream.current.value
lineno = next(parser.stream).lineno
default_bundle_name = u"%s" % (self.environment.default_bundle_name)
default_bundle_name.encode('utf-8')
bundle_name = nodes.Const(default_bundle_name)
#parse filename
if parser.stream.current.type != 'block_end':
value = parser.parse_expression()
# get first optional argument: bundle_name
if parser.stream.skip_if('comma'):
bundle_name = parser.parse_expression()
if isinstance(bundle_name, nodes.Name):
bundle_name = nodes.Name(bundle_name.name, 'load')
else:
value = parser.parse_tuple()
args = [nodes.Const(tag), value, bundle_name]
# Return html tag with link to corresponding script file.
if self.environment.use_bundle is False:
value = value.value
if callable(self.environment.collection_templates[tag]):
node = self.environment.collection_templates[tag](value)
else:
node = self.environment.collection_templates[tag] % value
return nodes.Output([nodes.MarkSafeIfAutoescape(nodes.Const(node))])
# Call :meth:`_update` to collect names of used scripts.
return nodes.CallBlock(self.call_method('_update', args=args,
lineno=lineno),
[], [], '')

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