|
| 1 | +"""Support for referencing Pipeline packages in forms and widgets.""" |
| 2 | + |
| 3 | +from __future__ import unicode_literals |
| 4 | + |
| 5 | +from django.contrib.staticfiles.storage import staticfiles_storage |
| 6 | +from django.utils import six |
| 7 | +from django.utils.functional import cached_property |
| 8 | + |
| 9 | +from .collector import default_collector |
| 10 | +from .conf import settings |
| 11 | +from .packager import Packager |
| 12 | + |
| 13 | + |
| 14 | +class PipelineFormMediaProperty(object): |
| 15 | + """A property that converts Pipeline packages to lists of files. |
| 16 | +
|
| 17 | + This is used behind the scenes for any Media classes that subclass |
| 18 | + :py:class:`PipelineFormMedia`. When accessed, it converts any Pipeline |
| 19 | + packages into lists of media files and returns or forwards on lookups to |
| 20 | + that list. |
| 21 | + """ |
| 22 | + |
| 23 | + def __init__(self, get_media_files_func, media_cls, extra_files): |
| 24 | + """Initialize the property. |
| 25 | +
|
| 26 | + Args: |
| 27 | + get_media_files_func (callable): |
| 28 | + The function to call to generate the media files. |
| 29 | +
|
| 30 | + media_cls (type): |
| 31 | + The Media class owning the property. |
| 32 | +
|
| 33 | + extra_files (object): |
| 34 | + Files listed in the original ``css`` or ``js`` attribute on |
| 35 | + the Media class. |
| 36 | + """ |
| 37 | + self._get_media_files_func = get_media_files_func |
| 38 | + self._media_cls = media_cls |
| 39 | + self._extra_files = extra_files |
| 40 | + |
| 41 | + @cached_property |
| 42 | + def _media_files(self): |
| 43 | + """The media files represented by the property.""" |
| 44 | + return self._get_media_files_func(self._media_cls, self._extra_files) |
| 45 | + |
| 46 | + def __get__(self, *args, **kwargs): |
| 47 | + """Return the media files when accessed as an attribute. |
| 48 | +
|
| 49 | + This is called when accessing the attribute directly through the |
| 50 | + Media class (for example, ``Media.css``). It returns the media files |
| 51 | + directly. |
| 52 | +
|
| 53 | + Args: |
| 54 | + *args (tuple, unused): |
| 55 | + Unused positional arguments. |
| 56 | +
|
| 57 | + **kwargs (dict, unused): |
| 58 | + Unused keyword arguments. |
| 59 | +
|
| 60 | + Returns: |
| 61 | + object: |
| 62 | + The list or dictionary containing the media files definition. |
| 63 | + """ |
| 64 | + return self._media_files |
| 65 | + |
| 66 | + def __getattr__(self, attr_name): |
| 67 | + """Return an attribute on the media files definition. |
| 68 | +
|
| 69 | + This is called when accessing an attribute that doesn't otherwise |
| 70 | + exist in the property's dictionary. The call is forwarded onto the |
| 71 | + media files definition. |
| 72 | +
|
| 73 | + Args: |
| 74 | + attr_name (unicode): |
| 75 | + The attribute name. |
| 76 | +
|
| 77 | + Returns: |
| 78 | + object: |
| 79 | + The attribute value. |
| 80 | +
|
| 81 | + Raises: |
| 82 | + AttributeError: |
| 83 | + An attribute with this name could not be found. |
| 84 | + """ |
| 85 | + return getattr(self._media_files, attr_name) |
| 86 | + |
| 87 | + def __iter__(self): |
| 88 | + """Iterate through the media files definition. |
| 89 | +
|
| 90 | + This is called when attempting to iterate over this property. It |
| 91 | + iterates over the media files definition instead. |
| 92 | +
|
| 93 | + Yields: |
| 94 | + object: |
| 95 | + Each entry in the media files definition. |
| 96 | + """ |
| 97 | + return iter(self._media_files) |
| 98 | + |
| 99 | + |
| 100 | +class PipelineFormMediaMetaClass(type): |
| 101 | + """Metaclass for the PipelineFormMedia class. |
| 102 | +
|
| 103 | + This is responsible for converting CSS/JavaScript packages defined in |
| 104 | + Pipeline into lists of files to include on a page. It handles access to the |
| 105 | + :py:attr:`css` and :py:attr:`js` attributes on the class, generating a |
| 106 | + list of files to return based on the Pipelined packages and individual |
| 107 | + files listed in the :py:attr:`css`/:py:attr:`css_packages` or |
| 108 | + :py:attr:`js`/:py:attr:`js_packages` attributes. |
| 109 | + """ |
| 110 | + |
| 111 | + def __new__(cls, name, bases, attrs): |
| 112 | + """Construct the class. |
| 113 | +
|
| 114 | + Args: |
| 115 | + name (bytes): |
| 116 | + The name of the class. |
| 117 | +
|
| 118 | + bases (tuple): |
| 119 | + The base classes for the class. |
| 120 | +
|
| 121 | + attrs (dict): |
| 122 | + The attributes going into the class. |
| 123 | +
|
| 124 | + Returns: |
| 125 | + type: |
| 126 | + The new class. |
| 127 | + """ |
| 128 | + new_class = super(PipelineFormMediaMetaClass, cls).__new__( |
| 129 | + cls, name, bases, attrs) |
| 130 | + |
| 131 | + # If we define any packages, we'll need to use our special |
| 132 | + # PipelineFormMediaProperty class. We use this instead of intercepting |
| 133 | + # in __getattribute__ because Django does not access them through |
| 134 | + # normal properpty access. Instead, grabs the Media class's __dict__ |
| 135 | + # and accesses them from there. By using these special properties, we |
| 136 | + # can handle direct access (Media.css) and dictionary-based access |
| 137 | + # (Media.__dict__['css']). |
| 138 | + if 'css_packages' in attrs: |
| 139 | + new_class.css = PipelineFormMediaProperty( |
| 140 | + cls._get_css_files, new_class, attrs.get('css') or {}) |
| 141 | + |
| 142 | + if 'js_packages' in attrs: |
| 143 | + new_class.js = PipelineFormMediaProperty( |
| 144 | + cls._get_js_files, new_class, attrs.get('js') or []) |
| 145 | + |
| 146 | + return new_class |
| 147 | + |
| 148 | + def _get_css_files(cls, extra_files): |
| 149 | + """Return all CSS files from the Media class. |
| 150 | +
|
| 151 | + Args: |
| 152 | + extra_files (dict): |
| 153 | + The contents of the Media class's original :py:attr:`css` |
| 154 | + attribute, if one was provided. |
| 155 | +
|
| 156 | + Returns: |
| 157 | + dict: |
| 158 | + The CSS media types and files to return for the :py:attr:`css` |
| 159 | + attribute. |
| 160 | + """ |
| 161 | + packager = Packager() |
| 162 | + css_packages = getattr(cls, 'css_packages', {}) |
| 163 | + |
| 164 | + return dict( |
| 165 | + (media_target, |
| 166 | + cls._get_media_files(packager=packager, |
| 167 | + media_packages=media_packages, |
| 168 | + media_type='css', |
| 169 | + extra_files=extra_files.get(media_target, |
| 170 | + []))) |
| 171 | + for media_target, media_packages in six.iteritems(css_packages) |
| 172 | + ) |
| 173 | + |
| 174 | + def _get_js_files(cls, extra_files): |
| 175 | + """Return all JavaScript files from the Media class. |
| 176 | +
|
| 177 | + Args: |
| 178 | + extra_files (list): |
| 179 | + The contents of the Media class's original :py:attr:`js` |
| 180 | + attribute, if one was provided. |
| 181 | +
|
| 182 | + Returns: |
| 183 | + list: |
| 184 | + The JavaScript files to return for the :py:attr:`js` attribute. |
| 185 | + """ |
| 186 | + return cls._get_media_files( |
| 187 | + packager=Packager(), |
| 188 | + media_packages=getattr(cls, 'js_packages', {}), |
| 189 | + media_type='js', |
| 190 | + extra_files=extra_files) |
| 191 | + |
| 192 | + def _get_media_files(cls, packager, media_packages, media_type, |
| 193 | + extra_files): |
| 194 | + """Return source or output media files for a list of packages. |
| 195 | +
|
| 196 | + This will go through the media files belonging to the provided list |
| 197 | + of packages referenced in a Media class and return the output files |
| 198 | + (if Pipeline is enabled) or the source files (if not enabled). |
| 199 | +
|
| 200 | + Args: |
| 201 | + packager (pipeline.packager.Packager): |
| 202 | + The packager responsible for media compilation for this type |
| 203 | + of package. |
| 204 | +
|
| 205 | + media_packages (list of unicode): |
| 206 | + The list of media packages referenced in Media to compile or |
| 207 | + return. |
| 208 | +
|
| 209 | + extra_files (list of unicode): |
| 210 | + The list of extra files to include in the result. This would |
| 211 | + be the list stored in the Media class's original :py:attr:`css` |
| 212 | + or :py:attr:`js` attributes. |
| 213 | +
|
| 214 | + Returns: |
| 215 | + list: |
| 216 | + The list of media files for the given packages. |
| 217 | + """ |
| 218 | + source_files = list(extra_files) |
| 219 | + |
| 220 | + if (not settings.PIPELINE_ENABLED and |
| 221 | + settings.PIPELINE_COLLECTOR_ENABLED): |
| 222 | + default_collector.collect() |
| 223 | + |
| 224 | + for media_package in media_packages: |
| 225 | + package = packager.package_for(media_type, media_package) |
| 226 | + |
| 227 | + if settings.PIPELINE_ENABLED: |
| 228 | + source_files.append( |
| 229 | + staticfiles_storage.url(package.output_filename)) |
| 230 | + else: |
| 231 | + source_files += packager.compile(package.paths) |
| 232 | + |
| 233 | + return source_files |
| 234 | + |
| 235 | + |
| 236 | +@six.add_metaclass(PipelineFormMediaMetaClass) |
| 237 | +class PipelineFormMedia(object): |
| 238 | + """Base class for form or widget Media classes that use Pipeline packages. |
| 239 | +
|
| 240 | + Forms or widgets that need custom CSS or JavaScript media on a page can |
| 241 | + define a standard :py:class:`Media` class that subclasses this class, |
| 242 | + listing the CSS or JavaScript packages in :py:attr:`css_packages` and |
| 243 | + :py:attr:`js_packages` attributes. These are formatted the same as the |
| 244 | + standard :py:attr:`css` and :py:attr:`js` attributes, but reference |
| 245 | + Pipeline package names instead of individual source files. |
| 246 | +
|
| 247 | + If Pipeline is enabled, these will expand to the output files for the |
| 248 | + packages. Otherwise, these will expand to the list of source files for the |
| 249 | + packages. |
| 250 | +
|
| 251 | + Subclasses can also continue to define :py:attr:`css` and :py:attr:`js` |
| 252 | + attributes, which will be returned along with the other output/source |
| 253 | + files. |
| 254 | +
|
| 255 | + Example: |
| 256 | +
|
| 257 | + from django import forms |
| 258 | + from pipeline.forms import PipelineFormMedia |
| 259 | +
|
| 260 | +
|
| 261 | + class MyForm(forms.Media): |
| 262 | + ... |
| 263 | +
|
| 264 | + class Media(PipelineFormMedia): |
| 265 | + css_packages = { |
| 266 | + 'all': ('my-form-styles-package', |
| 267 | + 'other-form-styles-package'), |
| 268 | + 'print': ('my-form-print-styles-package',), |
| 269 | + } |
| 270 | +
|
| 271 | + js_packages = ('my-form-scripts-package',) |
| 272 | + js = ('some-file.js',) |
| 273 | + """ |
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