I've been able to use flask-assets to bundle my css and js and serve using a versioned path. I also need to serve images using a versioned path, can webassets and flask-assets help me render images in my templates on versioned paths?

The cssrewrite filter doesn't work as expected with bundles exposed by a blueprint.

If a blueprint at /blueprint exposes css/blue.css as a static file, the Flask URL is /blueprint/css/blue.css. If this file is integrated into the app's static folder with cssrewrite, becoming /static/css/app.css, URLs aren't rewritten with ../../blueprint/css. They instead get ../blueprint/static/css, reflecting the actual path on disk.

Since Flask-Assets and webassets are capable of resolving paths to blueprints, this appears to be an oversight in the cssrewrite filter.

As far as I can see the Flask-Script 0.6 is not supported. Running command results in

Traceback (most recent call last):
  File "manage.py", line 15, in <module>
    manager.run()
  File "/blah/blah/blah/python2.7/site-packages/flask_script/__init__.py", line 366, in run
    raise e
TypeError: create_parser() got an unexpected keyword argument 'parents'

I tried everything, but if i choose pyScss as filter it just doesn't work. Keep getting "KeyError" on scss.STATIC_URL = self.env.url

For the past three months I've been running my production off git because of a bug in webassets 0.9. This seems fixed now but the flask-assets dependency is preventing me from using it - is there a significant showstopper from releasing a version of flask-assets that supports 0.10 webassets?

I want to use a packed assets file, but I never want it automatically updated because I'm updating it manually (by rendering the template once with assets.update = 'always').

The problem is that I can't seem to run flask-assets with both:

assets.debug = False

assets.updater = False

I get the error (even though the packed file exists):

BuildError: ... needs to be created, but automatic building is disabled (configure an updater)

I might be doing something dumb... but I can't figure it out.

BTW: I'm using google app engine

I have other packages in my environment having a requirement for the webassets package. These upgrade webassets to 0.9. And then while running pip installs with the --upgrade flag, I face an error which says:

error: Installed distribution webassets 0.9 conflicts with requirement webassets==0.8

On deeper probe, I figured it is flask-assets which has a specified dependency on webassets==0.8.

vagrant@dev:/usr/local/lib/python2.7/dist-packages$ sudo grep -r ==0.8 *
Flask_Assets-0.8-py2.7.egg/EGG-INFO/requires.txt:webassets==0.8

Any particular problem that holds flask-assets back from supporting webassets latest version?

I'm running Management Command (http://flask-assets.readthedocs.org/en/latest/index.html#management-command) to pre-build the bundle (I'm using GAE).

It works very well for bunble declared in code
bundle = Bundle('js/main.js', 'js/lib/bootstrap-2.0.3.min.js', filters="jsmin", output="gen/test.js")
assets_env.register('test', bundle)

But it doesn't seems to work with bundle declared in Template (couldn't detect this bundle)
{% assets filter="cssmin", output="gen/test.css",
"css/bootstrap-2.0.2.css", "css/bootstrap-responsive-2.0.2.css", "css/test.css" %}

{% endassets %}

Is template bundle detection working? Or am I missing some configurations?

$ pip install Flask-Assets -v
Downloading/unpacking Flask-Assets
  Using version 0.7 (newest of versions: 0.7, 0.6.2, 0.6.1, 0.6, 0.5.1, 0.2.2, 0.2.1, 0.2, 0.1)

$ pip install "Flask-Assets==0.8" --upgrade
Downloading/unpacking Flask-Assets==0.8
  Could not find a version that satisfies the requirement Flask-Assets==0.8 (from versions: )

I'm fairly new to python so I can't seem to figure out why this is not working properly, but it's really anoying because version 0.7 still uses from flaskext import script but Flask-Script has long moved on to only supporting from flask.ext import script so now I'm stuck with an old version of Flask-Script too!

Hey everyone,

I'm having an issue trying to use pyScss instead of the external sass filter. When I switch over to pyScss I get the following error:

File "/path/to/project/.env/lib/python2.7/site-packages/webassets/filter/pyscss.py", line 97, in setup
    scss.config.STATIC_ROOT = self.static_root or self.env.directory
AttributeError: 'module' object has no attribute 'config'

Here's the code I'm using to set up the environment:

app = Flask(__name__)
app.config["ASSETS_DEBUG"] = True

assets = Environment(app)
assets.url = app.static_url_path

scss = Bundle("stylesheets/main.scss", 
        filters="pyscss", 
        output="all.css", 
        depends="stylesheets/partials/*.scss")

assets.register("style", scss)

Nothing too complicated/fancy and it worked a-okay when pyscss was replaced with sass. I'm a bit confused as to what could be going wrong here. Any thoughts?

Thanks in advance!

Hello there, I think that webassets and the related Flask module are awesome and just had a few questions about the way files are read and structured within a Flask project.

Suppose we wish to keep track of 3 item types:

1. Non-compiled assets (e.g. LESS CSS, Stylus, Coffeescript .etc)
2. Compiled assets (e.g. CSS, JS)
3. Third party libraries used in a project (e.g. jQuery, Twitter Bootstrap)

I think a suitable directory structure would probably look something like this:

flask_project/assets/less/...   <- (1) Non-compiled assets
flask_project/assets/coffee/... <- (1) Non-compiled assets
flask_project/static/js/...     <- (2) Compiled assets
flask_project/static/js/...     <- (3) 3rd Party Libraries
flask_project/static/css/...    <- (2) Compiled assets
flask_project/static/css/...    <- (3) 3rd Party Libraries

I have been experimenting with Flask-Assets and can't seem to find a way to achieve this without doing something like this in the template:

{% assets filters="less", output="css/style.css",
          "../assets/less/style.less", "../assets/less/import.less" %}
    <link rel="stylesheet" type="text/css" media="screen" href="{{ ASSET_URL }}" />
{% endassets %}

I also attempted to use the ASSETS_LOAD_PATH config item but didn't have any luck.

Is there any way to specify the source directory independently from the destination directory?

Also another little question, is the cache really needed? For example, I pictured that it would work as follows.

1. I update my non-compiled source
2. The hash is saved in a dict (or similar)
3. An output file is generated
4. Next time I refresh the page, the hash is calculated against each file and compared to the value in the dict
5. If it has changed, repeat steps above

Please let me know your thoughts and if I'm missing something :)

Thank you so much and keep up the great work!
Fotis

When using a https proxy, such as Elastic Load Balancer, when configured to proxy https to http (middleman ssl) the flask application does not see the scheme as https. The simplest solution for this would be to render assets without a scheme, simply using //domain/public/asset.css

I would like to use flask-assets to organize my webassets and mako for templating. Flask-assets normally uses jinja in the following way:

{% assets "js_all" %}
    <script type="text/javascript" src="{{ ASSET_URL }}"></script>
{% endassets %}

The Mako equivalent (as far as I know) would be the following:

    % assets 'coffee':
        <script type="text/javascript" src="{{ ASSET_URL }}"></script>
    % endassets

However this causes a compile error:

mako.exceptions.CompileException
CompileException: Unsupported control keyword: 'assets' in file '/index.html' at line: 8 char: 1

Is there any way to use custom control keywords (like 'assets') in Mako, or set up Flask-Assets to interact with Mako?

I'm deploying my Flask app in a location that requires a prefix in the URL and I'm using a middleware to prepend the prefix to the WSGI's SCRIPT_NAME. When this is used in combination with Flask-Assets, the resulting URLs for assets are incorrect, as they are not processed within the same request context and they lack the prefix.

For reference on the issue, see the Flask mailing list thread.

See https://github.com/sean-lynch/flask-assets-issues/blob/master/1/app.py for an example

If an environment has both assets.updater = 'always' and assets.cache = False, the JST file generated breaks itself after the second time the page is loaded. In the example, the first time the bundle is generated, the result is:

window.JST = window.JST || {};
var template = function(str){/* ... common JST code ... */};
window.JST['template'] = template('

When the page is refreshed and the bundle is generated a second time, it becomes:

window.JST = window.JST || {};
var template = function(str){/* ... common JST code ... */};
window.JST[''] = template('

Couldn't replicate this using webassets directly.

For retrieving assets in production.

The docs say that these are equivalent.

assets_env.debug = True
app.config['ASSETS_DEBUG'] = True

When I try this

assets_env = Environment()
assets_env.debug = True
assets_env.init_app(app)

I get RuntimeError: assets instance not bound to an application, and no application in current context.

However this works.

assets_env = Environment()
app.config['ASSETS_DEBUG'] = True
assets_env.init_app(app)

It would be good if the docs had a warning about this.

This is what happens when I run the test suite.

$ python2.7 setup.py test
running test
running egg_info
writing requirements to src/Flask_Assets.egg-info/requires.txt
writing src/Flask_Assets.egg-info/PKG-INFO
writing top-level names to src/Flask_Assets.egg-info/top_level.txt
writing dependency_links to src/Flask_Assets.egg-info/dependency_links.txt
reading manifest file 'src/Flask_Assets.egg-info/SOURCES.txt'
reading manifest template 'MANIFEST.in'
no previously-included directories found matching 'docs/_build'
no previously-included directories found matching 'docs/_themes/.git'
warning: no previously-included files matching '*.pyc' found under directory 'example'
writing manifest file 'src/Flask_Assets.egg-info/SOURCES.txt'
running build_ext
tests.test_config.TestConfigAppBound.test_custom_values
Custom config values are relayed to the Flask config as.is. ... ok
tests.test_config.TestConfigAppBound.test_no_override
Ensure that the webassets defaults do not override existing ... ok
tests.test_config.TestConfigAppBound.test_set_config
Setting a value in the Flask config works. ... ok
tests.test_config.TestConfigAppBound.test_set_environment
Setting a config value on the environment works. ... ok
tests.test_config.TestConfigNoAppBound.test_global_defaults
We may set defaults even without an application, however. ... ok
tests.test_config.TestConfigNoAppBound.test_key_error
KeyError is raised if a config value doesn't exist. ... ok
tests.test_config.TestConfigNoAppBound.test_multiple_separate_apps
Each app has it's own separate configuration. ... ok
tests.test_config.TestConfigNoAppBound.test_no_app_available
Without an application bound, we can't do much. ... ok
tests.test_env.TestEnv.test_from_python_module
Python configuration module gets loaded ... ok
tests.test_env.TestEnv.test_from_yaml
YAML configuration gets loaded ... ok
tests.test_env.TestEnv.test_tag_available
Jinja tag has been made available. ... ok
tests.test_integration.TestBlueprints.test_blueprint_no_static_folder
Test dealing with a blueprint without a static folder. ... ok
tests.test_integration.TestBlueprints.test_blueprint_output
[Regression] Output can point to a blueprint's static ... ok
tests.test_integration.TestBlueprints.test_blueprint_urls
Urls to blueprint files are generated correctly. ... ok
tests.test_integration.TestBlueprints.test_cssrewrite
Make sure cssrewrite works with Blueprints. ... ok
tests.test_integration.TestBuild.test_build ... ok
tests.test_integration.TestBuild.test_with_cache_default_directory
[Regression] The cache directory is created in the Flask ... ok
tests.test_integration.TestUrlAndDirectory.test_config_values_not_set_by_default ... ok
tests.test_integration.TestUrlAndDirectory.test_custom_directory_and_url
Custom directory/url are configured - this will affect how ... ok
tests.test_integration.TestUrlAndDirectory.test_custom_load_path
A custom load_path is configured - this will affect how ... ok
tests.test_integration.TestUrlAndDirectory.test_directory_auto
Test how we resolve file references through the Flask static ... ok
tests.test_integration.TestUrlAndDirectory.test_existing_request_object_used
[Regression] Check for a bug where the url generation code of ... ok
tests.test_integration.TestUrlAndDirectory.test_glob
Make sure url generation works with globs. ... ok
tests.test_integration.TestUrlAndDirectory.test_url_auto
Test how urls are generated via the Flask static system ... ok
tests.test_integration.TestUrlAndDirectoryWithInitApp.test
Make sure the "url" and "directory" config values are ... ok
tests.test_integration.test_import ... ok
tests.test_script.TestScript.test_call ... ERROR
tests.test_script.TestScript.test_call_auto_env
Regression test: Passing the environment to the ManageAssets command ... ok
tests.test_script.TestScript.test_parse_templates
Test the --parse-templates option. ... ok

======================================================================
ERROR: tests.test_script.TestScript.test_call
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/home/edward/src/deb_dist/flask-assets-0.11/tests/test_script.py", line 52, in test_call
    assert self.last_script_call == ['-h']
AttributeError: 'TestScript' object has no attribute 'last_script_call'
-------------------- >> begin captured stdout << ---------------------
usage: manage.py assets [-h]

Manage assets.

optional arguments:
  -h, --help  show this help message and exit

--------------------- >> end captured stdout << ----------------------

----------------------------------------------------------------------
Ran 29 tests in 0.201s

FAILED (errors=1)
$

Specifically, how to tell flask to spit out the CDN hostname instead of /static/ depending on a config var. Should I override url_for somehow or change how ASSET_URL works?

I've searched the web and there doesn't seem to be one standard way to do this (in flask at all, regardless of flask-assets). Any advice would be appreciated.

Allo,

app.config['ASSETS_DEBUG']

{% assets filters="cssmin", output="css/gen/style.css", 
"css/bootstrap.css", "css/bootstrap-responsive.css", "css/custom.css" -%}  
<link href="{{ ASSET_URL }}" rel="stylesheet">
{%- endassets %}
{% assets filters="cssutils", output="css/gen/style.css", 
"css/bootstrap.css", "css/bootstrap-responsive.css", "css/custom.css" -%}
<link href="{{ ASSET_URL }}" rel="stylesheet">
{%- endassets %}

<head>
<link href="/static/css/bootstrap.css" rel="stylesheet">
<link href="/static/css/bootstrap-responsive.css" rel="stylesheet">
<link href="/static/css/custom.css" rel="stylesheet">
<link href="/static/css/gen/style.css?f54629cf" rel="stylesheet">
</head>

I would love to use flask-assets CDN integration, but the current release (0.10) does not have it.

Thanks for a great library.

Just running tox to test another application, and this is the tail end of the error:

File "/.../.tox/py33/lib/python3.3/site-packages/flask_assets.py", line 5, in <module>
from webassets.env import (  File "/..../.tox/py33/lib/python3.3/site-packages/webassets/__init__.py", line 5, in <module>
from bundle import Bundle
ImportError: No module named 'bundle'

Heya, I'm using flask-assets and find it quite awesome. One of the things I find lacking, however, is a filter that simply processes a file through Jinja2.

webassets doesn't include this at all, which makes it difficult to write purely CSS-driven sites. For instance, I often find myself writing HTML minimally, and specifying all image paths in my CSS files, eg:

body {
    background: url({{ config.STATIC_URL }}/img/background.png);
}

This allows me to easily control the style of my site without actually touching the template layer. Also: I can serve static files locally in development, while serving them from something like S3 in production.

Anyhow, in order for me to do the above, I have to process my template with a custom webasset filter that uses Flask's render_template_string function (so that I get all the standard Flask contexts: url_for, config, g, etc.).

What I'm wondering is this: if I submit a pull request which contains my custom Jinja2 filter for use with webassets, would you consider accepting it? I thought about submitting it to the webassets project itself, but after thinking about it, I think it would be difficult to get accepted there since this filter is only useful when paired with the standard Flask contexts.

Anyhow, let me know! If you'd like me to, I'd be happy to submit a pull request with the filter, it's very simple.

Attempting to use the following pattern, then setting config values, like so...:

app = Flask(__name__)
assets = flask.ext.assets.Environment() # note no app being passed via constructor
assets.init_app(app) # initializing assets via init_app() here...
assets.cache = False # <--- ERROR!
assets.debug = True  # <--- ERROR!

…results in errors (marked above) RuntimeError: assets instance not bound to an application, and no application in current context.

Examining further, it seems that the init_app() method does not set self.app, causing the _app property to throw the exception when subsequent attempts to use the ostensibly "init'd app" via init_app().

Current Code (~line 328 in flask_assets.py):

def init_app(self, app):
        app.jinja_env.add_extension('webassets.ext.jinja2.AssetsExtension')
        app.jinja_env.assets_environment = self

Proposed Solution - add single line…:

def init_app(self, app):
        self.app = app  # <--- setting the self.app to satisfy `._app` property!
        app.jinja_env.add_extension('webassets.ext.jinja2.AssetsExtension')
        app.jinja_env.assets_environment = self

the standard way of render url takes 3 lines

{% assets 'main_css' %}
    <link rel="stylesheet" href="{{ASSET_URL}}">
{% endassets %}

This seems to be a bit verbose
I am wondering if it's possible to provide helper function in template like this:

<link rel="stylesheet" href="{{asset_url('main_css')}}">

I have a bundle defined like this:

bootstrap_js = Bundle(
  "libs/bootstrap/js/*.js"
)

Since a few days ago (I guess with the new release) the glob is not working, instead of having multiple URLs I get one to "http://localhost:8080/static/libs/bootstrap/js/*.js"

After a quick look in the source code I didn't find an easy fix, but I think it's got something to do with the method FlaskResolver.resolve_source_to_url.

Also, I did a git bisect and it told me the first bad commit is 3d9913f

I'd be happy to provide more info if you want.

Hello there Michael, hope you're doing well 😄

It seems that the assets management command extension for Flask-Script fails to work on most versions of Python.

Here's my test script:

#!/usr/bin/env python
from flask import Flask
from flask.ext.script import Manager
from flask.ext.assets import Environment, Bundle, ManageAssets

app = Flask(__name__)
assets_env = Environment(app)
js = Bundle('jquery.js', 'base.js', 'widgets.js',
            filters='jsmin', output='gen/packed.js')
assets_env.register('js_all', js)

manager = Manager(app)
manager.add_command("assets", ManageAssets(assets_env))

if __name__ == '__main__':
    manager.run()

For each example below, I created a virtualenv using the version of Python mentioned and then installed the following:

pip install Flask-Script Flask-Assets

Python 2.6.9: This doesn't allow me to use sub-options at all I'm afraid

(scripts-2.6.9)fots@fotsies-ubprecise-01:~/flask-assets-test$ python -V
Python 2.6.9
(scripts-2.6.9)fots@fotsies-ubprecise-01:~/flask-assets-test$ ./testit.py assets
usage: testit.py assets [-h] [-v] [-q] [--parse-templates]
                        {watch,build,clean,check} ...
testit.py assets: error: too few arguments
(scripts-2.6.9)fots@fotsies-ubprecise-01:~/flask-assets-test$ ./testit.py assets check
usage: testit.py assets [-h]
testit.py assets: error: unrecognized arguments: check

Python 2.7.6: This works as expected

(scripts-2.7.6)fots@fotsies-ubprecise-01:~/flask-assets-test$ python -V
Python 2.7.6
(scripts-2.7.6)fots@fotsies-ubprecise-01:~/flask-assets-test$ ./testit.py assets
usage: testit.py assets [-h] [-v] [-q] [--parse-templates]
                        {watch,build,clean,check} ...
testit.py assets: error: too few arguments
(scripts-2.7.6)fots@fotsies-ubprecise-01:~/flask-assets-test$ ./testit.py assets check
Checking asset: gen/packed.js
  needs update

Python 3.3.5: Fails to list command help, but seems to respond to sub-options

(scripts-3.3.5) fots@fotsies-ubprecise-01:~/flask-assets-test$ python -V
Python 3.3.5
(scripts-3.3.5) fots@fotsies-ubprecise-01:~/flask-assets-test$ ./testit.py assets
unknown command: None
(scripts-3.3.5) fots@fotsies-ubprecise-01:~/flask-assets-test$ ./testit.py assets check
Checking asset: gen/packed.js
  needs update

Python 3.4.0: Same as Python 3.3.5 above

(scripts-3.4) fots@fotsies-ubprecise-01:~/flask-assets-test$ python -V
Python 3.4.0
(scripts-3.4) fots@fotsies-ubprecise-01:~/flask-assets-test$ ./testit.py assets
unknown command: None
(scripts-3.4) fots@fotsies-ubprecise-01:~/flask-assets-test$ ./testit.py assets check
Checking asset: gen/packed.js
  needs update

Any help would be greatly appreciated! 😄

Cheers
Fotis

How do i gzip the assets created with flask assets.

At the bottom of this documentation it discusses a number of topics I am interested in, but none of the italicised text are links, so I can't figure out how to get there.

http://flask-assets.readthedocs.org/en/latest/

It breaks cssrewrite filter, because my blueprint has a url_prefix with a <param> and url_for needs the url_defaults to build the URL.

Currently the latest stable release is not compatible with how Flask handles the exception, see this commit: 006864b.

So we can’t use ManageAsset() with Flask-Script for example.

The fix is already present in master, when will you push the next major version?

I am getting the following error when I try to build assets using the --parse-templates option. Im not really sure where to start debugging this...

Searching templates...
Traceback (most recent call last):
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/jinja2/nodes.py", line 386, in as_const
    return f(self.left.as_const(eval_ctx), self.right.as_const(eval_ctx))
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/jinja2/nodes.py", line 365, in as_const
    raise Impossible()
jinja2.nodes.Impossible

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/jinja2/nodes.py", line 386, in as_const
    return f(self.left.as_const(eval_ctx), self.right.as_const(eval_ctx))
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/jinja2/nodes.py", line 388, in as_const
    raise Impossible()
jinja2.nodes.Impossible

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "manage.py", line 110, in <module>
    manager.run()
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/flask_script/__init__.py", line 412, in run
    result = self.handle(sys.argv[0], sys.argv[1:])
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/flask_script/__init__.py", line 383, in handle
    res = handle(*args, **config)
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/flask_script/commands.py", line 216, in __call__
    return self.run(*args, **kwargs)
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/flask_assets.py", line 422, in run
    return impl.main(args)
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/webassets/script.py", line 557, in main
    return self.run_with_argv(argv)
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/webassets/script.py", line 549, in run_with_argv
    return self.run_with_ns(ns)
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/webassets/script.py", line 531, in run_with_ns
    env = self._setup_assets_env(ns, log)
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/flask_assets.py", line 364, in _setup_assets_env
    env.add(*[b for b in self.load_from_templates(env, ns.jinja_extension)
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/flask_assets.py", line 391, in load_from_templates
    load_bundles()
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/webassets/ext/jinja2.py", line 218, in load_bundles
    bundles.extend(self.with_file(filename, self._parse) or [])
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/webassets/loaders.py", line 301, in with_file
    return then_run(filename, contents)
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/webassets/ext/jinja2.py", line 246, in _parse
    _recurse_node(node)
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/webassets/ext/jinja2.py", line 244, in _recurse_node
    _recurse_node(node)
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/webassets/ext/jinja2.py", line 237, in _recurse_node
    *AssetsExtension.resolve_contents(files.as_const(), self.asset_env),
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/jinja2/nodes.py", line 490, in as_const
    return [x.as_const(eval_ctx) for x in self.items]
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/jinja2/nodes.py", line 490, in <listcomp>
    return [x.as_const(eval_ctx) for x in self.items]
  File "/Users/joe/Sites/_projects/words/venv3/lib/python3.4/site-packages/jinja2/nodes.py", line 388, in as_const
    raise Impossible()
jinja2.nodes.Impossible

I have a deploy procedure where i want to compile the static assets locally, commit them to the repo and then don't compile in production. This way the server does not need any extra packages like node, yahoo compile etc.

Also this will not stall the initial request by compiling the assets. Is there any plan for an option like this or should i work on that.

@miracle2k This has gotten a bit out of hand. There are 3 open issue open that have to do with the inability to get the correct version of of webassets. Moreover, it has made it quite difficult to get new installations up and breaks builds.

The cleanest solution is to eliminate the parse_version function in setup.py entirely and simply update the specific version in setup.py as things progress. As stated in the Zen of Python, "Explicit is better than implicit", "Simple is better than complex", and "Readability counts". Unfortunately, right now I think this setup is in contradiction with each of these.

Hi,

I get KeyError exceptions with 0.6, complaining about missing directory key. The following code works with 0.5.1, but not with 0.6:

https://gist.github.com/1274982

I am using the less and it works beautifully. Now how do i minify the css.

{% assets filters="less", output="gen/packed.css", "less/bootstrap.less" %}
    <link href="{{ ASSET_URL }}" rel="stylesheet">
{% endassets %}

less supports -x option. how do i specify it. If not how do i specify multiple filters.

Second where do i mention this

if env.debug:
    js_bundle.contents += 'http://lesscss.googlecode.com/files/less-1.3.0.min.js'

and this

env.config['less_run_in_debug'] = False

Hi,

Would you be interested in having support for bower integrated into Flask-Assets or Webassets? What we have in mind is being able to specify bower dependencies in Bundles, e.g.:

css = Bundle(
    'less/styles.less',
    filters='less, cleancss',
    output='gen/styles.%(version)s.css',
    bower={
        "bootstrap": "~3.3.5",
    }
)

Then have a CLI command similar to below to collect bower requirements from all bundles in an environment in order to generate a bower.json:

$ manage.py bower
{
  "name": "",
  "dependencies": {
    "bootstrap": "~3.3.5",
  }
}

A typical use would be like below (generate bower.json, run bower install, then build assets):

$ manage.py bower --output-file bower.json
$ bower install
$ manage.py assets build

The difference from just writing a bower.json in your text editor is that it allows an application to integrate external bundles without having to worry about which assets you need to download (e.g. collecting bower requirements from all applications in INSTALLED_APPS in a Django).

If it has any interest, we'll be happy to create a PR, otherwise just close the issue.

Cheers,
Lars

For some reason the def _app is returning nothing, but if set self.app in init_app ist works.

The Function init_app should look like this:

def init_app(self, app):
    self.app = app
    app.jinja_env.add_extension('webassets.ext.jinja2.AssetsExtension')
    app.jinja_env.assets_environment = self

If you setup your Flask installation as describe here: http://flask.pocoo.org/docs/patterns/packages/#modules-and-resources, flask-assets isn't able to find static files stored in the module's static directory.

This would be useful for assets that are small when compressed.

I am setting config variables for Flask-Asset's in the documentation, for example

# Flask-Assets / webassets
ASSETS_DEBUG = True
ASSETS_UGLIFYJS_EXTRA_ARGS = ['-nc']

I am initializing the assets environment in an application factory:

assets = Environment()

def create_app(config=None):
    app = Flask(__name__)
    if config is not None:
        app.config.from_object(config)
    db.init_app(app)
    assets.init_app(app)

While the DEBUG option works fine.. the extra args for uglifyjs do not get passed. Perhaps I am doing something wrong? Are all Flask config options prepended with ASSETS_ parsed?

Thanks again for webassets + Flask-Assets. Truly invaluable.

Is there a way I can add assets to a bundle within a route?

Hi, i don't know if its realy a flask-assets bug but it appears when using it.

All my web projects on the server worked with flask-assets fine, since some time. All projects at the same time broked.

From all projects i got: ImportError: No module named flask.ext.assets

When i activate the env (all projects are installed in virtualenvs) and do the same import, it will work.

So i don't know if its realy a flask-assts problem but i hope you can help me.

$ pip freeze
Flask==0.10.1
Flask-Assets==0.8
Flask-Mail==0.9.0
Flask-WTF==0.9.1
Jinja2==2.7.1
MarkupSafe==0.18
WTForms==1.0.4
Werkzeug==0.9.4
blinker==1.3
cssmin==0.1.4
distribute==0.7.3
itsdangerous==0.23
webassets==0.8
wsgiref==0.1.2

How to use spritemapper filter.
Maybe an example of usage of all builtins filters are welcome.

i have flask application with buildout in src folder

./bin/pip show flask | grep Version

Version: 0.10.1

./bin/pip show flask-assets | grep Version

Version: 0.10

src/setup.py have following strings

setup(
    name = 'spf',
    install_requires = [
        'flask',
        'flask-assets',
    ],
    entry_points = {
        'console_scripts': [
            'spf_dev = spf.manage:dev', /* see manage.py dev function */
        ],
    },
}

src/spf/manage.py

from flask.ext import assets
from . import env

def init (app):
    manager = script.Manager(app)

    manager.add_command(
        'assets',
        assets.ManageAssets(app.assets),
    )
    return manager

def dev ():
    init(env.dev.app).run()

src/spf/env/dev.py

from spf import init
app = init({
    'ASSETS_DIR': 'src/spf/static/assets',
    'ASSETS_URL': '/assets/',

    'SASS_STYLE': 'compressed',

    'UGLIFYJS_EXTRA_ARGS': (
        '-c',
        '--screw-ie8',
    ),

})

src/spf/init.py

import flask
from . import assets

def init (env_config=None):
    app = flask.Flask(
        'spf',
        static_url_path='',
    )

    app.config.update(evn_config)
    app.assets = assets.Assets(app)
    return app

src/spf/assets.py

from flask.ext.assets import (
    Environment,
    Bundle,
)

class Assets (Environment):
    def __init__ (self, app):
        super(Assets, self).__init__(app)

        if 'ASSETS_DIR' in app.config:
            self.directory = app.config['ASSETS_DIR']

        if 'ASSETS_URL' in app.config:
            self.url = app.config['ASSETS_URL']

        if 'SASS_STYLE' in app.config:
            self.config['sass_style'] =  app.config['SASS_STYLE']

        if 'UGLIFYJS_EXTRA_ARGS' in app.config:
            self.config['UGLIFYJS_EXTRA_ARGS'] = \
                app.config['UGLIFYJS_EXTRA_ARGS']

        self.register('theme.css', Bundle(
            'scss/theme.scss',
            filters='scss',
            output='theme.css',
        ))

        self.append_path('src/assets')

src/assets/scss/theme.scss

@import 'btn-o';

src/assets/scss/_btn-o.scss exists and have 0777 access right

but when i run
./bin/spf_dev assets -v build

i have error

Building bundle: theme.css
Failed, error was: sass: subprocess had error: stderr=Error: File to import not found or unreadable: ./btn-o. on line 1 of standard input
  Use --trace for backtrace. , stdout=, returncode=65

i have read https://github.com/miracle2k/webassets/blob/master/src/webassets/filter/sass.py#L36

but i don't understand
why sass don't use src/assets for resolve relative path in @import directive from stdin?

self.append_path('src/assets')

The flask-script "clean" command fails with:

Cleaning generated assets...
Traceback (most recent call last):
File "manage.py", line 29, in
manager.run()
File "C:\Python27\lib\site-packages\flask_script__init__.py", line 412, in run
result = self.handle(sys.argv[0], sys.argv[1:])
File "C:\Python27\lib\site-packages\flask_script__init__.py", line 383, in handle
res = handle(_args, *_config)
File "C:\Python27\lib\site-packages\flask_script\commands.py", line 216, in call
return self.run(_args, *_kwargs)
File "C:\Python27\lib\site-packages\flask_assets.py", line 422, in run
return impl.main(args)
File "C:\Python27\lib\site-packages\webassets\script.py", line 557, in main
return self.run_with_argv(argv)
File "C:\Python27\lib\site-packages\webassets\script.py", line 549, in run_with_argv
return self.run_with_ns(ns)
File "C:\Python27\lib\site-packages\webassets\script.py", line 539, in run_with_ns
return cmd.invoke(ns.command, args)
File "C:\Python27\lib\site-packages\webassets\script.py", line 373, in invoke
return function(**args)
File "C:\Python27\lib\site-packages\webassets\script.py", line 299, in call
file_path = bundle.resolve_output(self.environment)
File "C:\Python27\lib\site-packages\webassets\bundle.py", line 326, in resolve_output
output = ctx.resolver.resolve_output_to_path(ctx, self.output, self)
File "C:\Python27\lib\site-packages\flask_assets.py", line 201, in resolve_output_to_path
directory, rel_path, endpoint = self.split_prefix(ctx, target)
File "C:\Python27\lib\site-packages\flask_assets.py", line 152, in split_prefix
app = ctx.environment._app
AttributeError: 'Environment' object has no attribute 'environment'

The build command works. The flask-script manager was initialized with:

manager.add_command("assets", ManageAssets(assets))

#36 fixes the broken globbing funtionality, could you release this fix to pypi?

I just want to merge js files but not compress it. How do i do it.

(venv)[myapp] ./manage.py assets --parse-templates build
Searching templates...
Traceback (most recent call last):
  File "./manage.py", line 61, in <module>
    manager.run()
  File "/Users/philfreo/Sites/_es/myapp/venv/lib/python2.7/site-packages/flaskext/script.py", line 710, in run
    self.handle(sys.argv[0], command, sys.argv[2:])
  File "/Users/philfreo/Sites/_es/myapp/venv/lib/python2.7/site-packages/flaskext/script.py", line 682, in handle
    command.handle(app, *positional_args, **command_namespace.__dict__)
  File "/Users/philfreo/Sites/_es/myapp/venv/lib/python2.7/site-packages/flaskext/script.py", line 193, in handle
    self.run(*args, **kwargs)
  File "/Users/philfreo/Sites/_es/myapp/venv/src/flask-assets/src/flask_assets.py", line 345, in run
    impl.main(args)
  File "/Users/philfreo/Sites/_es/myapp/venv/src/webassets/src/webassets/script.py", line 555, in main
    return self.run_with_argv(argv)
  File "/Users/philfreo/Sites/_es/myapp/venv/src/webassets/src/webassets/script.py", line 547, in run_with_argv
    return self.run_with_ns(ns)
  File "/Users/philfreo/Sites/_es/myapp/venv/src/webassets/src/webassets/script.py", line 529, in run_with_ns
    env = self._setup_assets_env(ns, log)
  File "/Users/philfreo/Sites/_es/myapp/venv/src/flask-assets/src/flask_assets.py", line 287, in _setup_assets_env
    env.add(*[b for b in self.load_from_templates(env)
  File "/Users/philfreo/Sites/_es/myapp/venv/src/flask-assets/src/flask_assets.py", line 309, in load_from_templates
    path.join(blueprint.root_path, blueprint.template_folder))
AttributeError: 'str' object has no attribute 'root_path'

Looks like blueprint is a string for all the blueprints in app.blueprints. Did I setup something wrong or is this a bug?