edx-platform/common/lib/xmodule/xmodule/static_content.py

# /usr/bin/env python
"""
This module has utility functions for gathering up the static content
that is defined by XModules and XModuleDescriptors (javascript and css)
"""

import logging
import hashlib
import os
import errno
import sys
from collections import defaultdict
from docopt import docopt
from path import path

from xmodule.x_module import XModuleDescriptor


LOG = logging.getLogger(__name__)


def write_module_styles(output_root):
    return _write_styles('.xmodule_display', output_root, _list_modules())


def write_module_js(output_root):
    return _write_js(output_root, _list_modules())


def write_descriptor_styles(output_root):
    return _write_styles('.xmodule_edit', output_root, _list_descriptors())


def write_descriptor_js(output_root):
    return _write_js(output_root, _list_descriptors())


def _list_descriptors():
    return [
        desc for desc in [
            desc for (_, desc) in XModuleDescriptor.load_classes()
        ]
    ]


def _list_modules():
    return [
        desc.module_class
        for desc
        in _list_descriptors()
    ]


def _ensure_dir(dir_):
    try:
        os.makedirs(dir_)
    except OSError as exc:
        if exc.errno == errno.EEXIST:
            pass
        else:
            raise


def _write_styles(selector, output_root, classes):
    """
    Write the css fragments from all XModules in `classes`
    into `output_root` as individual files, hashed by the contents to remove
    duplicates
    """
    contents = {}

    css_fragments = defaultdict(set)
    for class_ in classes:
        class_css = class_.get_css()
        for filetype in ('sass', 'scss', 'css'):
            for idx, fragment in enumerate(class_css.get(filetype, [])):
                css_fragments[idx, filetype, fragment].add(class_.__name__)
    css_imports = defaultdict(set)
    for (idx, filetype, fragment), classes in sorted(css_fragments.items()):
        fragment_name = "{idx:0=3d}-{hash}.{type}".format(
            idx=idx,
            hash=hashlib.md5(fragment).hexdigest(),
            type=filetype)
        # Prepend _ so that sass just includes the files into a single file
        filename = '_' + fragment_name
        contents[filename] = fragment

        for class_ in classes:
            css_imports[class_].add(fragment_name)

    module_styles_lines = []
    module_styles_lines.append("@import 'bourbon/bourbon';")
    module_styles_lines.append("@import 'bourbon/addons/button';")
    for class_, fragment_names in css_imports.items():
        module_styles_lines.append("""{selector}.xmodule_{class_} {{""".format(
            class_=class_, selector=selector
        ))
        module_styles_lines.extend('  @import "{0}";'.format(name) for name in fragment_names)
        module_styles_lines.append('}')

    contents['_module-styles.scss'] = '\n'.join(module_styles_lines)

    _write_files(output_root, contents)


def _write_js(output_root, classes):
    """
    Write the javascript fragments from all XModules in `classes`
    into `output_root` as individual files, hashed by the contents to remove
    duplicates
    """
    contents = {}

    js_fragments = set()
    for class_ in classes:
        module_js = class_.get_javascript()
        for filetype in ('coffee', 'js'):
            for idx, fragment in enumerate(module_js.get(filetype, [])):
                js_fragments.add((idx, filetype, fragment))

    for idx, filetype, fragment in sorted(js_fragments):
        filename = "{idx:0=3d}-{hash}.{type}".format(
            idx=idx,
            hash=hashlib.md5(fragment).hexdigest(),
            type=filetype)
        contents[filename] = fragment

    _write_files(output_root, contents, {'.coffee': '.js'})

    return [output_root / filename for filename in contents.keys()]


def _write_files(output_root, contents, generated_suffix_map=None):
    _ensure_dir(output_root)
    to_delete = set(file.basename() for file in output_root.files()) - set(contents.keys())

    if generated_suffix_map:
        for output_file in contents.keys():
            for suffix, generated_suffix in generated_suffix_map.items():
                if output_file.endswith(suffix):
                    to_delete.discard(output_file.replace(suffix, generated_suffix))

    for extra_file in to_delete:
        (output_root / extra_file).remove_p()

    for filename, file_content in contents.iteritems():
        output_file = output_root / filename

        if not output_file.isfile() or output_file.read_md5() != hashlib.md5(file_content).digest():
            LOG.debug("Writing %s", output_file)
            output_file.write_bytes(file_content)
        else:
            LOG.debug("%s unchanged, skipping", output_file)


def main():
    """
    Generate
    Usage: static_content.py <output_root>
    """
    args = docopt(main.__doc__)
    root = path(args['<output_root>'])

    write_descriptor_js(root / 'descriptors/js')
    write_descriptor_styles(root / 'descriptors/css')
    write_module_js(root / 'modules/js')
    write_module_styles(root / 'modules/css')


if __name__ == '__main__':
    sys.exit(main())