Source

tw2.core / tw2 / core / resources.py

The default branch has multiple heads

Full commit
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
import re
import logging
import itertools
import os
import webob as wo
import pkg_resources as pr
import mimetypes
import simplejson
import inspect
import warnings

import widgets as wd
import util
import core
import params as pm
import middleware as md
from js import encoder, js_symbol

log = logging.getLogger(__name__)


# TBD is there a better place to put this?
mimetypes.init()
mimetypes.types_map['.ico'] = 'image/x-icon'


class JSSymbol(js_symbol):
    """ Deprecated compatibility shim with old TW2 stuff.  Use js_symbol. """

    def __init__(self, *args, **kw):
        warnings.warn("JSSymbol is deprecated.  Please use js_symbol")

        if len(args) > 1:
            raise ValueError("JSSymbol must receive up to only one arg.")

        if len(args) == 1 and 'src' in kw:
            raise ValueError("JSSymbol must receive only one src arg.")

        if len(args) == 1:
            kw['src'] = args[0]

        super(JSSymbol, self).__init__(**kw)

        # Backwards compatibility for accessing the source.
        self.src = self._name


class ResourceBundle(wd.Widget):
    """ Just a list of resources.

    Use it as follows:

        >>> jquery_ui = ResourceBundle(resources=[jquery_js, jquery_css])
        >>> jquery_ui.inject()

    """

    @classmethod
    def inject(cls):
        cls.req().prepare()

    def prepare(self):
        super(ResourceBundle, self).prepare()

        rl = core.request_local()
        rl_resources = rl.setdefault('resources', [])
        rl_location = rl['middleware'].config.inject_resources_location

        if self not in rl_resources:
            for r in self.resources:
                r.req().prepare()


class Resource(ResourceBundle):
    location = pm.Param(
        'Location on the page where the resource should be placed.' \
        'This can be one of: head, headbottom, bodytop or bodybottom. '\
        'None means the resource will not be injected, which is still '\
        'useful, e.g. static images.', default=None)
    id = None

    def prepare(self):
        super(Resource, self).prepare()

        rl = core.request_local()
        rl_resources = rl.setdefault('resources', [])
        rl_location = rl['middleware'].config.inject_resources_location

        if self not in rl_resources:
            if self.location is '__use_middleware':
                self.location = rl_location

            rl_resources.append(self)


class Link(Resource):
    '''
    A link to a file.
    '''
    id = None
    link = pm.Param(
        'Direct web link to file. If this is not specified, it is ' +
        'automatically generated, based on :attr:`modname` and ' +
        ':attr:`filename`.',
    )
    modname = pm.Param(
        'Name of Python module that contains the file.',
        default=None,
    )
    filename = pm.Param(
        'Path to file, relative to module base.',
        default=None,
    )
    no_inject = pm.Param(
        "Don't inject this link. (Default: False)",
        default=False,
    )
    whole_dir = pm.Param(
        "Make the whole directory available.  (Default: False)",
        default=False,
    )

    @classmethod
    def guess_modname(cls):
        """ Try to guess my modname.

        If I wasn't supplied any modname, take a guess by stepping back up the
        frame stack until I find something not in tw2.core
        """

        try:
            frame, i = inspect.stack()[0][0], 0
            while frame.f_globals['__name__'].startswith('tw2.core'):
                frame, i = inspect.stack()[i][0], i + 1

            return frame.f_globals['__name__']
        except Exception:
            return None

    @classmethod
    def post_define(cls):

        if not cls.modname:
            cls.modname = cls.guess_modname()

        if not cls.no_inject:
            if getattr(cls, 'filename', None) and \
               type(cls.filename) != property:

                md.register_resource(
                    cls.modname or '__anon__', cls.filename, cls.whole_dir
                )

    def prepare(self):
        rl = core.request_local()
        if not self.no_inject:
            if not hasattr(self, 'link'):
                # TBD shouldn't we test for this in __new__ ?
                if not self.filename:
                    raise pm.ParameterError(
                        "Either 'link' or 'filename' must be specified"
                    )
                resources = rl['middleware'].resources
                self.link = resources.resource_path(
                    self.modname or '__anon__', self.filename
                )
            super(Link, self).prepare()

    def __hash__(self):
        return hash(
            hasattr(self, 'link') and \
            self.link or \
            ((self.modname or '') + self.filename)
        )

    def __eq__(self, other):
        attrs = ['link', 'modname', 'filename']
        return all([
            getattr(self, attr, None) == getattr(other, attr, None)
            for attr in attrs
        ])

    def __repr__(self):
        return "%s('%s')" % (
            self.__class__.__name__,
            getattr(self, 'link', '%s/%s' % (self.modname, self.filename))
        )


class DirLink(Link):
    link = pm.Variable()
    filename = pm.Required
    whole_dir = True

    def prepare(self):
        resources = core.request_local()['middleware'].resources
        self.link = resources.resource_path(
            self.modname,
            self.filename,
        )


class JSLink(Link):
    '''
    A JavaScript source file.
    '''
    location = '__use_middleware'
    template = 'tw2.core.templates.jslink'


class CSSLink(Link):
    '''
    A CSS style sheet.
    '''
    media = pm.Param('Media tag', default='all')
    location = 'head'
    template = 'tw2.core.templates.csslink'


class JSSource(Resource):
    """
    Inline JavaScript source code.
    """
    src = pm.Param('Source code', default=None)
    location = 'bodybottom'
    template = 'tw2.core.templates.jssource'

    def __repr__(self):
        return "%s('%s')" % (self.__class__.__name__, self.src)


class CSSSource(Resource):
    """
    Inline Cascading Style-Sheet code.
    """
    src = pm.Param('CSS code', default=None)
    location = 'head'
    template = 'tw2.core.templates.csssource'

    def __repr__(self):
        return "%s('%s')" % (self.__class__.__name__, self.src)


class _JSFuncCall(JSSource):
    """
    Internal use inline JavaScript function call.

    Please use tw2.core.js_function(...) externally.
    """
    src = None
    function = pm.Param('Function name')
    args = pm.Param('Function arguments', default=None)
    location = 'bodybottom'  # TBD: afterwidget?

    def __str__(self):
        if not self.src:
            self.prepare()
        return self.src

    def prepare(self):
        if not self.src:
            args = ''
            if isinstance(self.args, dict):
                args = encoder.encode(self.args)
            elif self.args:
                args = ', '.join(encoder.encode(a) for a in self.args)

            self.src = '%s(%s)' % (self.function, args)
        super(_JSFuncCall, self).prepare()

    def __hash__(self):
        if self.args:
            if isinstance(self.args, dict):
                sargs = encoder.encode(self.args)
            else:
                sargs = ', '.join(encoder.encode(a) for a in self.args)
        else:
            sargs = None

        return hash((hasattr(self, 'src') and self.src or '') + (sargs or ''))

    def __eq__(self, other):
        return (getattr(self, 'src', None) == getattr(other, 'src', None)
                and getattr(self, 'args', None) == getattr(other, 'args', None)
                )


class ResourcesApp(object):
    """WSGI Middleware to serve static resources

    This handles URLs like this:
        /resources/tw2.forms/static/forms.css

    Where:
        resources       is the prefix
        tw2.forms       is a python package name
        static          is a directory inside the package
        forms.css       is the file to retrieve

    For this to work, the file must have been registered in advance,
    using :meth:`register`. There is a ResourcesApp instance for each
    TwMiddleware instance.
    """

    def __init__(self, config):
        self._paths = {}
        self._dirs = []
        self.config = config

    def register(self, modname, filename, whole_dir=False):
        """ Register a file for static serving.

        After this method has been called, for say ('tw2.forms',
        'static/forms.css'), the URL /resources/tw2.forms/static/forms.css will
        then serve that file from within the tw2.forms package. This works
        correctly for zipped eggs.

        *Security Consideration* - This file will be readable by users of the
        application, so make sure it contains no confidential data. For
        DirLink resources, the whole directory, and subdirectories will be
        readable.

        `modname`
            The python module that contains the file to publish. You can also
            pass a pkg_resources.Requirement instance to point to the root of
            an egg distribution.

        `filename`
            The path, relative to the base of the module, of the file to be
            published. If *modname* is None, it's an absolute path.
        """
        if isinstance(modname, pr.Requirement):
            modname = os.path.basename(pr.working_set.find(modname).location)

        path = modname + '/' + filename.lstrip('/')

        if whole_dir:
            if path not in self._dirs:
                self._dirs.append(path)
        else:
            if path not in self._paths:
                self._paths[path] = (modname, filename)

    def resource_path(self, modname, filename):
        """ Return a resource's web path. """

        if isinstance(modname, pr.Requirement):
            modname = os.path.basename(pr.working_set.find(modname).location)

        path = modname + '/' + filename.lstrip('/')
        return self.config.script_name + self.config.res_prefix + path

    def __call__(self, environ, start_response):
        req = wo.Request(environ)
        try:
            path = environ['PATH_INFO']
            path = path[len(self.config.res_prefix):]

            if path not in self._paths:
                if '..' in path:  # protect against directory traversal
                    raise IOError()
                for d in self._dirs:
                    if path.startswith(d.replace('\\', '/')):
                        break
                else:
                    raise IOError()
            modname, filename = path.lstrip('/').split('/', 1)
            ct, enc = mimetypes.guess_type(os.path.basename(filename))
            if modname and modname != '__anon__':
                stream = pr.resource_stream(modname, filename)
            else:
                stream = open(filename)
        except IOError:
            resp = wo.Response(status="404 Not Found")
        else:
            stream = _FileIter(stream, self.config.bufsize)
            resp = wo.Response(app_iter=stream, content_type=ct)
            if enc:
                resp.content_type_params['charset'] = enc
        resp.cache_control = {'max-age': int(self.config.res_max_age)}
        return resp(environ, start_response)


# Could use wsgiref, but this is python 2.4 compatible
class _FileIter(object):
    def __init__(self, fileobj, bufsize):
        self.fileobj = fileobj
        self.bufsize = bufsize

    def __iter__(self):
        return self

    def next(self):
        buf = self.fileobj.read(self.bufsize)
        if not buf:
            raise StopIteration
        return buf

    def close(self):
        self.fileobj.close()


class _ResourceInjector(util.MultipleReplacer):
    """
    ToscaWidgets can inject resources that have been registered for injection
    in the current request.

    Usually widgets register them when they're displayed and they have
    instances of :class:`tw2.core.resources.Resource` declared at their
    :attr:`tw2.core.Widget.javascript` or :attr:`tw2.core.Widget.css`
    attributes.

    Resources can also be registered manually from a controller or template by
    calling their :meth:`tw2.core.resources.Resource.inject` method.

    When a page including widgets is rendered, Resources that are registered
    for injection are collected in a request-local storage area (this means
    any thing stored here is only visible to one single thread of execution
    and that its contents are freed when the request is finished) where they
    can be rendered and injected in the resulting html.

    ToscaWidgets' middleware can take care of injecting them automatically
    (default) but they can also be injected explicitly, example::

       >>> from tw2.core.resources import JSLink, inject_resources
       >>> JSLink(link="http://example.com").inject()
       >>> html = "<html><head></head><body></body></html>"
       >>> inject_resources(html)
       '<html><head><script type="text/javascript"
        src="http://example.com"></script></head><body></body></html>'

    Once resources have been injected they are popped from request local and
    cannot be injected again (in the same request). This is useful in case
    :class:`injector_middleware` is stacked so it doesn't inject them again.

    Injecting them explicitly is neccesary if the response's body is being
    cached before the middleware has a chance to inject them because when the
    cached version is served no widgets are being rendered so they will not
    have a chance to register their resources.
    """

    def __init__(self):
        return util.MultipleReplacer.__init__(self, {
            r'<head(?!er).*?>': self._injector_for_location('head'),
            r'</head(?!er).*?>': self._injector_for_location(
                'headbottom', False
            ),
            r'<body.*?>': self._injector_for_location('bodytop'),
            r'</body.*?>': self._injector_for_location('bodybottom', False)
        }, re.I | re.M)

    def _injector_for_location(self, key, after=True):
        def inject(group, resources, encoding):
            inj = u'\n'.join([
                r.display(displays_on='string')
                for r in resources
                if r.location == key
            ])
            inj = inj.encode(encoding)
            if after:
                return group + inj
            return  inj + group
        return inject

    def __call__(self, html, resources=None, encoding=None):
        """Injects resources, if any, into html string when called.

        .. note::
           Ignore the ``self`` parameter if seeing this as
           :func:`tw.core.resource_injector.inject_resources` docstring
           since it is an alias for an instance method of a private class.

        ``html`` must be a ``encoding`` encoded string. If ``encoding`` is not
        given it will be tried to be derived from a <meta>.

        """
        if resources is None:
            resources = core.request_local().get('resources', None)
        if resources:
            encoding = encoding or find_charset(html) or 'utf-8'
            html = util.MultipleReplacer.__call__(
                self, html, resources, encoding
            )
            core.request_local().pop('resources', None)
        return html


# Bind __call__ directly so docstring is included in docs
inject_resources = _ResourceInjector().__call__


_charset_re = re.compile(
    r"charset\s*=\s*(?P<charset>[\w-]+)([^\>])*", re.I | re.M)


def find_charset(string):
    m = _charset_re.search(string)
    if m:
        return m.group('charset').lower()