| # mako/lookup.py |
| # Copyright (C) 2006-2016 the Mako authors and contributors <see AUTHORS file> |
| # |
| # This module is part of Mako and is released under |
| # the MIT License: http://www.opensource.org/licenses/mit-license.php |
| |
| import os |
| import stat |
| import posixpath |
| import re |
| from mako import exceptions, util |
| from mako.template import Template |
| |
| try: |
| import threading |
| except: |
| import dummy_threading as threading |
| |
| |
| class TemplateCollection(object): |
| |
| """Represent a collection of :class:`.Template` objects, |
| identifiable via URI. |
| |
| A :class:`.TemplateCollection` is linked to the usage of |
| all template tags that address other templates, such |
| as ``<%include>``, ``<%namespace>``, and ``<%inherit>``. |
| The ``file`` attribute of each of those tags refers |
| to a string URI that is passed to that :class:`.Template` |
| object's :class:`.TemplateCollection` for resolution. |
| |
| :class:`.TemplateCollection` is an abstract class, |
| with the usual default implementation being :class:`.TemplateLookup`. |
| |
| """ |
| |
| def has_template(self, uri): |
| """Return ``True`` if this :class:`.TemplateLookup` is |
| capable of returning a :class:`.Template` object for the |
| given ``uri``. |
| |
| :param uri: String URI of the template to be resolved. |
| |
| """ |
| try: |
| self.get_template(uri) |
| return True |
| except exceptions.TemplateLookupException: |
| return False |
| |
| def get_template(self, uri, relativeto=None): |
| """Return a :class:`.Template` object corresponding to the given |
| ``uri``. |
| |
| The default implementation raises |
| :class:`.NotImplementedError`. Implementations should |
| raise :class:`.TemplateLookupException` if the given ``uri`` |
| cannot be resolved. |
| |
| :param uri: String URI of the template to be resolved. |
| :param relativeto: if present, the given ``uri`` is assumed to |
| be relative to this URI. |
| |
| """ |
| raise NotImplementedError() |
| |
| def filename_to_uri(self, uri, filename): |
| """Convert the given ``filename`` to a URI relative to |
| this :class:`.TemplateCollection`.""" |
| |
| return uri |
| |
| def adjust_uri(self, uri, filename): |
| """Adjust the given ``uri`` based on the calling ``filename``. |
| |
| When this method is called from the runtime, the |
| ``filename`` parameter is taken directly to the ``filename`` |
| attribute of the calling template. Therefore a custom |
| :class:`.TemplateCollection` subclass can place any string |
| identifier desired in the ``filename`` parameter of the |
| :class:`.Template` objects it constructs and have them come back |
| here. |
| |
| """ |
| return uri |
| |
| |
| class TemplateLookup(TemplateCollection): |
| |
| """Represent a collection of templates that locates template source files |
| from the local filesystem. |
| |
| The primary argument is the ``directories`` argument, the list of |
| directories to search: |
| |
| .. sourcecode:: python |
| |
| lookup = TemplateLookup(["/path/to/templates"]) |
| some_template = lookup.get_template("/index.html") |
| |
| The :class:`.TemplateLookup` can also be given :class:`.Template` objects |
| programatically using :meth:`.put_string` or :meth:`.put_template`: |
| |
| .. sourcecode:: python |
| |
| lookup = TemplateLookup() |
| lookup.put_string("base.html", ''' |
| <html><body>${self.next()}</body></html> |
| ''') |
| lookup.put_string("hello.html", ''' |
| <%include file='base.html'/> |
| |
| Hello, world ! |
| ''') |
| |
| |
| :param directories: A list of directory names which will be |
| searched for a particular template URI. The URI is appended |
| to each directory and the filesystem checked. |
| |
| :param collection_size: Approximate size of the collection used |
| to store templates. If left at its default of ``-1``, the size |
| is unbounded, and a plain Python dictionary is used to |
| relate URI strings to :class:`.Template` instances. |
| Otherwise, a least-recently-used cache object is used which |
| will maintain the size of the collection approximately to |
| the number given. |
| |
| :param filesystem_checks: When at its default value of ``True``, |
| each call to :meth:`.TemplateLookup.get_template()` will |
| compare the filesystem last modified time to the time in |
| which an existing :class:`.Template` object was created. |
| This allows the :class:`.TemplateLookup` to regenerate a |
| new :class:`.Template` whenever the original source has |
| been updated. Set this to ``False`` for a very minor |
| performance increase. |
| |
| :param modulename_callable: A callable which, when present, |
| is passed the path of the source file as well as the |
| requested URI, and then returns the full path of the |
| generated Python module file. This is used to inject |
| alternate schemes for Python module location. If left at |
| its default of ``None``, the built in system of generation |
| based on ``module_directory`` plus ``uri`` is used. |
| |
| All other keyword parameters available for |
| :class:`.Template` are mirrored here. When new |
| :class:`.Template` objects are created, the keywords |
| established with this :class:`.TemplateLookup` are passed on |
| to each new :class:`.Template`. |
| |
| """ |
| |
| def __init__(self, |
| directories=None, |
| module_directory=None, |
| filesystem_checks=True, |
| collection_size=-1, |
| format_exceptions=False, |
| error_handler=None, |
| disable_unicode=False, |
| bytestring_passthrough=False, |
| output_encoding=None, |
| encoding_errors='strict', |
| |
| cache_args=None, |
| cache_impl='beaker', |
| cache_enabled=True, |
| cache_type=None, |
| cache_dir=None, |
| cache_url=None, |
| |
| modulename_callable=None, |
| module_writer=None, |
| default_filters=None, |
| buffer_filters=(), |
| strict_undefined=False, |
| imports=None, |
| future_imports=None, |
| enable_loop=True, |
| input_encoding=None, |
| preprocessor=None, |
| lexer_cls=None, |
| include_error_handler=None): |
| |
| self.directories = [posixpath.normpath(d) for d in |
| util.to_list(directories, ()) |
| ] |
| self.module_directory = module_directory |
| self.modulename_callable = modulename_callable |
| self.filesystem_checks = filesystem_checks |
| self.collection_size = collection_size |
| |
| if cache_args is None: |
| cache_args = {} |
| # transfer deprecated cache_* args |
| if cache_dir: |
| cache_args.setdefault('dir', cache_dir) |
| if cache_url: |
| cache_args.setdefault('url', cache_url) |
| if cache_type: |
| cache_args.setdefault('type', cache_type) |
| |
| self.template_args = { |
| 'format_exceptions': format_exceptions, |
| 'error_handler': error_handler, |
| 'include_error_handler': include_error_handler, |
| 'disable_unicode': disable_unicode, |
| 'bytestring_passthrough': bytestring_passthrough, |
| 'output_encoding': output_encoding, |
| 'cache_impl': cache_impl, |
| 'encoding_errors': encoding_errors, |
| 'input_encoding': input_encoding, |
| 'module_directory': module_directory, |
| 'module_writer': module_writer, |
| 'cache_args': cache_args, |
| 'cache_enabled': cache_enabled, |
| 'default_filters': default_filters, |
| 'buffer_filters': buffer_filters, |
| 'strict_undefined': strict_undefined, |
| 'imports': imports, |
| 'future_imports': future_imports, |
| 'enable_loop': enable_loop, |
| 'preprocessor': preprocessor, |
| 'lexer_cls': lexer_cls |
| } |
| |
| if collection_size == -1: |
| self._collection = {} |
| self._uri_cache = {} |
| else: |
| self._collection = util.LRUCache(collection_size) |
| self._uri_cache = util.LRUCache(collection_size) |
| self._mutex = threading.Lock() |
| |
| def get_template(self, uri): |
| """Return a :class:`.Template` object corresponding to the given |
| ``uri``. |
| |
| .. note:: The ``relativeto`` argument is not supported here at |
| the moment. |
| |
| """ |
| |
| try: |
| if self.filesystem_checks: |
| return self._check(uri, self._collection[uri]) |
| else: |
| return self._collection[uri] |
| except KeyError: |
| u = re.sub(r'^\/+', '', uri) |
| for dir in self.directories: |
| # make sure the path seperators are posix - os.altsep is empty |
| # on POSIX and cannot be used. |
| dir = dir.replace(os.path.sep, posixpath.sep) |
| srcfile = posixpath.normpath(posixpath.join(dir, u)) |
| if os.path.isfile(srcfile): |
| return self._load(srcfile, uri) |
| else: |
| raise exceptions.TopLevelLookupException( |
| "Cant locate template for uri %r" % uri) |
| |
| def adjust_uri(self, uri, relativeto): |
| """Adjust the given ``uri`` based on the given relative URI.""" |
| |
| key = (uri, relativeto) |
| if key in self._uri_cache: |
| return self._uri_cache[key] |
| |
| if uri[0] != '/': |
| if relativeto is not None: |
| v = self._uri_cache[key] = posixpath.join( |
| posixpath.dirname(relativeto), uri) |
| else: |
| v = self._uri_cache[key] = '/' + uri |
| else: |
| v = self._uri_cache[key] = uri |
| return v |
| |
| def filename_to_uri(self, filename): |
| """Convert the given ``filename`` to a URI relative to |
| this :class:`.TemplateCollection`.""" |
| |
| try: |
| return self._uri_cache[filename] |
| except KeyError: |
| value = self._relativeize(filename) |
| self._uri_cache[filename] = value |
| return value |
| |
| def _relativeize(self, filename): |
| """Return the portion of a filename that is 'relative' |
| to the directories in this lookup. |
| |
| """ |
| |
| filename = posixpath.normpath(filename) |
| for dir in self.directories: |
| if filename[0:len(dir)] == dir: |
| return filename[len(dir):] |
| else: |
| return None |
| |
| def _load(self, filename, uri): |
| self._mutex.acquire() |
| try: |
| try: |
| # try returning from collection one |
| # more time in case concurrent thread already loaded |
| return self._collection[uri] |
| except KeyError: |
| pass |
| try: |
| if self.modulename_callable is not None: |
| module_filename = self.modulename_callable(filename, uri) |
| else: |
| module_filename = None |
| self._collection[uri] = template = Template( |
| uri=uri, |
| filename=posixpath.normpath(filename), |
| lookup=self, |
| module_filename=module_filename, |
| **self.template_args) |
| return template |
| except: |
| # if compilation fails etc, ensure |
| # template is removed from collection, |
| # re-raise |
| self._collection.pop(uri, None) |
| raise |
| finally: |
| self._mutex.release() |
| |
| def _check(self, uri, template): |
| if template.filename is None: |
| return template |
| |
| try: |
| template_stat = os.stat(template.filename) |
| if template.module._modified_time < \ |
| template_stat[stat.ST_MTIME]: |
| self._collection.pop(uri, None) |
| return self._load(template.filename, uri) |
| else: |
| return template |
| except OSError: |
| self._collection.pop(uri, None) |
| raise exceptions.TemplateLookupException( |
| "Cant locate template for uri %r" % uri) |
| |
| def put_string(self, uri, text): |
| """Place a new :class:`.Template` object into this |
| :class:`.TemplateLookup`, based on the given string of |
| ``text``. |
| |
| """ |
| self._collection[uri] = Template( |
| text, |
| lookup=self, |
| uri=uri, |
| **self.template_args) |
| |
| def put_template(self, uri, template): |
| """Place a new :class:`.Template` object into this |
| :class:`.TemplateLookup`, based on the given |
| :class:`.Template` object. |
| |
| """ |
| self._collection[uri] = template |
