X-Git-Url: http://git.ithinksw.org/philo.git/blobdiff_plain/ed6b9876b7abff0b2dc6266d6f769c319f358a9c..f5ef756179b62eb9a87983936c2576586632d8d7:/philo/contrib/sobol/search.py diff --git a/philo/contrib/sobol/search.py b/philo/contrib/sobol/search.py index 39b93c7..a79030a 100644 --- a/philo/contrib/sobol/search.py +++ b/philo/contrib/sobol/search.py @@ -1,4 +1,6 @@ #encoding: utf-8 +import datetime +from hashlib import sha1 from django.conf import settings from django.contrib.sites.models import Site @@ -8,248 +10,264 @@ from django.utils import simplejson as json from django.utils.http import urlquote_plus from django.utils.safestring import mark_safe from django.utils.text import capfirst -from django.template import loader, Context, Template -import datetime +from django.template import loader, Context, Template, TemplateDoesNotExist + from philo.contrib.sobol.utils import make_tracking_querydict +from philo.utils.registry import Registry -try: - from eventlet.green import urllib2 -except: + +if getattr(settings, 'SOBOL_USE_EVENTLET', False): + try: + from eventlet.green import urllib2 + except: + import urllib2 +else: import urllib2 __all__ = ( - 'Result', 'BaseSearch', 'DatabaseSearch', 'URLSearch', 'JSONSearch', 'GoogleSearch', 'registry' + 'Result', 'BaseSearch', 'DatabaseSearch', 'URLSearch', 'JSONSearch', 'GoogleSearch', 'registry', 'get_search_instance' ) -SEARCH_CACHE_KEY = 'philo_sobol_search_results' -DEFAULT_RESULT_TEMPLATE_STRING = "{% if url %}{% endif %}{{ title }}{% if url %}{% endif %}" -DEFAULT_RESULT_TEMPLATE = Template(DEFAULT_RESULT_TEMPLATE_STRING) +SEARCH_CACHE_SEED = 'philo_sobol_search_results' +USE_CACHE = getattr(settings, 'SOBOL_USE_CACHE', True) -# Determines the timeout on the entire result cache. -MAX_CACHE_TIMEOUT = 60*24*7 +#: A registry for :class:`BaseSearch` subclasses that should be available in the admin. +registry = Registry() -class RegistrationError(Exception): - pass - -class SearchRegistry(object): - # Holds a registry of search types by slug. - def __init__(self): - self._registry = {} - - def register(self, search, slug=None): - slug = slug or search.slug - if slug in self._registry: - registered = self._registry[slug] - if registered.__module__ != search.__module__: - raise RegistrationError("A different search is already registered as `%s`" % slug) - else: - self._registry[slug] = search - - def unregister(self, search, slug=None): - if slug is not None: - if slug in self._registry and self._registry[slug] == search: - del self._registry[slug] - raise RegistrationError("`%s` is not registered as `%s`" % (search, slug)) - else: - for slug, search in self._registry.items(): - if search == search: - del self._registry[slug] - - def items(self): - return self._registry.items() - - def iteritems(self): - return self._registry.iteritems() - - def iterchoices(self): - for slug, search in self.iteritems(): - yield slug, search.verbose_name - - def __getitem__(self, key): - return self._registry[key] - - def __iter__(self): - return self._registry.__iter__() +def _make_cache_key(search, search_arg): + return sha1(SEARCH_CACHE_SEED + search.slug + search_arg).hexdigest() -registry = SearchRegistry() +def get_search_instance(slug, search_arg): + """Returns a search instance for the given slug, either from the cache or newly-instantiated.""" + search = registry[slug] + search_arg = search_arg.lower() + if USE_CACHE: + key = _make_cache_key(search, search_arg) + cached = cache.get(key) + if cached: + return cached + instance = search(search_arg) + instance.slug = slug + return instance class Result(object): """ - A result is instantiated with a configuration dictionary, a search, - and a template name. The configuration dictionary is expected to - define a `title` and optionally a `url`. Any other variables may be - defined; they will be made available through the result object in - the template, if one is defined. + :class:`Result` is a helper class that, given a search and a result of that search, is able to correctly render itself with a template defined by the search. Every :class:`Result` will pass a ``title``, a ``url`` (if applicable), and the raw ``result`` returned by the search into the template context when rendering. + + :param search: An instance of a :class:`BaseSearch` subclass or an object that implements the same API. + :param result: An arbitrary result from the ``search``. + """ def __init__(self, search, result): self.search = search self.result = result def get_title(self): + """Returns the title of the result by calling :meth:`BaseSearch.get_result_title` on the raw result.""" return self.search.get_result_title(self.result) def get_url(self): - qd = self.search.get_result_querydict(self.result) - if qd is None: - return "" - return "?%s" % qd.urlencode() + """Returns the url of the result or ``None`` by calling :meth:`BaseSearch.get_result_url` on the raw result. This url will contain a querystring which, if used, will track a :class:`.Click` for the actual url.""" + return self.search.get_result_url(self.result) + + def get_actual_url(self): + """Returns the actual url of the result by calling :meth:`BaseSearch.get_actual_result_url` on the raw result.""" + return self.search.get_actual_result_url(self.result) + + def get_content(self): + """Returns the content of the result by calling :meth:`BaseSearch.get_result_content` on the raw result.""" + return self.search.get_result_content(self.result) def get_template(self): + """Returns the template which will be used to render the :class:`Result` by calling :meth:`BaseSearch.get_result_template` on the raw result.""" return self.search.get_result_template(self.result) - def get_extra_context(self): - return self.search.get_result_extra_context(self.result) - def get_context(self): - context = self.get_extra_context() - context.update({ - 'title': self.get_title(), - 'url': self.get_url() - }) - return context + """ + Returns the context dictionary for the result. This is used both in rendering the result and in the AJAX return value for :meth:`.SearchView.ajax_api_view`. The context will contain the following keys: + + title + The result of calling :meth:`get_title` + url + The result of calling :meth:`get_url` + content + The result of calling :meth:`get_content` + + """ + if not hasattr(self, '_context'): + self._context = { + 'title': self.get_title(), + 'url': self.get_url(), + 'actual_url': self.get_actual_url(), + 'content': self.get_content() + } + return self._context def render(self): + """Returns the template from :meth:`get_template` rendered with the context from :meth:`get_context`.""" t = self.get_template() c = Context(self.get_context()) return t.render(c) def __unicode__(self): + """Returns :meth:`render`""" return self.render() class BaseSearchMetaclass(type): def __new__(cls, name, bases, attrs): if 'verbose_name' not in attrs: - attrs['verbose_name'] = capfirst(convert_camelcase(name)) + attrs['verbose_name'] = capfirst(' '.join(convert_camelcase(name).rsplit(' ', 1)[:-1])) if 'slug' not in attrs: - attrs['slug'] = name.lower() + attrs['slug'] = name[:-6].lower() if name.endswith("Search") else name.lower() return super(BaseSearchMetaclass, cls).__new__(cls, name, bases, attrs) class BaseSearch(object): """ - Defines a generic search interface. Accessing self.results will - attempt to retrieve cached results and, if that fails, will - initiate a new search and store the results in the cache. + Defines a generic search api. Accessing :attr:`results` will attempt to retrieve cached results and, if that fails, will initiate a new search and store the results in the cache. Each search has a ``verbose_name`` and a ``slug``. If these are not provided as attributes, they will be automatically generated based on the name of the class. + + :param search_arg: The string which is being searched for. + """ __metaclass__ = BaseSearchMetaclass - result_limit = 10 + #: The number of results to return from the complete list. Default: 5 + result_limit = 5 + #: How long the items for the search should be cached (in minutes). Default: 48 hours. _cache_timeout = 60*48 + #: The path to the template which will be used to render the :class:`Result`\ s for this search. If this is ``None``, then the framework will try ``sobol/search//result.html`` and ``sobol/search/result.html``. + result_template = None + #: The path to the template which will be used to generate the title of the :class:`Result`\ s for this search. If this is ``None``, then the framework will try ``sobol/search//title.html`` and ``sobol/search/title.html``. + title_template = None + #: The path to the template which will be used to generate the content of the :class:`Result`\ s for this search. If this is ``None``, then the framework will try ``sobol/search//content.html`` and ``sobol/search/content.html``. + content_template = None def __init__(self, search_arg): self.search_arg = search_arg - def _get_cached_results(self): - """Return the cached results if the results haven't timed out. Otherwise return None.""" - result_cache = cache.get(SEARCH_CACHE_KEY) - if result_cache and self.__class__ in result_cache and self.search_arg.lower() in result_cache[self.__class__]: - cached = result_cache[self.__class__][self.search_arg.lower()] - if cached['timeout'] >= datetime.datetime.now(): - return cached['results'] - return None - - def _set_cached_results(self, results, timeout): - """Sets the results to the cache for minutes.""" - result_cache = cache.get(SEARCH_CACHE_KEY) or {} - cached = result_cache.setdefault(self.__class__, {}).setdefault(self.search_arg.lower(), {}) - cached.update({ - 'results': results, - 'timeout': datetime.datetime.now() + datetime.timedelta(minutes=timeout) - }) - cache.set(SEARCH_CACHE_KEY, result_cache, MAX_CACHE_TIMEOUT) - @property def results(self): + """Retrieves cached results or initiates a new search via :meth:`get_results` and caches the results.""" if not hasattr(self, '_results'): - results = self._get_cached_results() - if results is None: - try: - # Cache one extra result so we can see if there are - # more results to be had. - limit = self.result_limit - if limit is not None: - limit += 1 - results = self.get_results(limit) - except: - if settings.DEBUG: - raise - # On exceptions, don't set any cache; just return. - return [] + try: + # Cache one extra result so we can see if there are + # more results to be had. + limit = self.result_limit + if limit is not None: + limit += 1 + results = self.get_results(limit) + except: + if settings.DEBUG: + raise + # On exceptions, don't set any cache; just return. + return [] - self._set_cached_results(results, self._cache_timeout) self._results = results + + if USE_CACHE: + for result in results: + result.get_context() + key = _make_cache_key(self, self.search_arg) + cache.set(key, self, self._cache_timeout) return self._results def get_results(self, limit=None, result_class=Result): """ - Calls self.search() and parses the return value into Result objects. + Calls :meth:`search` and parses the return value into :class:`Result` instances. + + :param limit: Passed directly to :meth:`search`. + :param result_class: The class used to represent the results. This will be instantiated with the :class:`BaseSearch` instance and the raw result from the search. + """ results = self.search(limit) return [result_class(self, result) for result in results] def search(self, limit=None): - """ - Returns an iterable of up to results. The - get_result_title, get_result_url, get_result_template, and - get_result_extra_context methods will be used to interpret the - individual items that this function returns, so the result can - be an object with attributes as easily as a dictionary - with keys. The only restriction is that the objects be - pickleable so that they can be used with django's cache system. - """ + """Returns an iterable of up to ``limit`` results. The :meth:`get_result_title`, :meth:`get_result_url`, :meth:`get_result_template`, and :meth:`get_result_extra_context` methods will be used to interpret the individual items that this function returns, so the result can be an object with attributes as easily as a dictionary with keys. However, keep in mind that the raw results will be stored with django's caching mechanisms and will be converted to JSON.""" raise NotImplementedError - def get_result_title(self, result): - raise NotImplementedError - - def get_result_url(self, result): - "Subclasses override this to provide the actual URL for the result." + def get_actual_result_url(self, result): + """Returns the actual URL for the ``result`` or ``None`` if there is no URL. Must be implemented by subclasses.""" raise NotImplementedError def get_result_querydict(self, result): - url = self.get_result_url(result) + """Returns a querydict for tracking selection of the result, or ``None`` if there is no URL for the result.""" + url = self.get_actual_result_url(result) if url is None: return None return make_tracking_querydict(self.search_arg, url) + def get_result_url(self, result): + """Returns ``None`` or a url which, when accessed, will register a :class:`.Click` for that url.""" + qd = self.get_result_querydict(result) + if qd is None: + return None + return "?%s" % qd.urlencode() + + def get_result_title(self, result): + """Returns the title of the ``result``. By default, renders ``sobol/search//title.html`` or ``sobol/search/title.html`` with the result in the context. This can be overridden by setting :attr:`title_template` or simply overriding :meth:`get_result_title`. If no template can be found, this will raise :exc:`TemplateDoesNotExist`.""" + return loader.render_to_string(self.title_template or [ + 'sobol/search/%s/title.html' % self.slug, + 'sobol/search/title.html' + ], {'result': result}) + + def get_result_content(self, result): + """Returns the content for the ``result``. By default, renders ``sobol/search//content.html`` or ``sobol/search/content.html`` with the result in the context. This can be overridden by setting :attr:`content_template` or simply overriding :meth:`get_result_content`. If no template is found, this will return an empty string.""" + try: + return loader.render_to_string(self.content_template or [ + 'sobol/search/%s/content.html' % self.slug, + 'sobol/search/content.html' + ], {'result': result}) + except TemplateDoesNotExist: + return "" + def get_result_template(self, result): - if hasattr(self, 'result_template'): + """Returns the template to be used for rendering the ``result``. For a search with slug ``google``, this would first try ``sobol/search/google/result.html``, then fall back on ``sobol/search/result.html``. Subclasses can override this by setting :attr:`result_template` to the path of another template.""" + if self.result_template: return loader.get_template(self.result_template) - if not hasattr(self, '_result_template'): - self._result_template = DEFAULT_RESULT_TEMPLATE - return self._result_template - - def get_result_extra_context(self, result): - return {} + return loader.select_template([ + 'sobol/search/%s/result.html' % self.slug, + 'sobol/search/result.html' + ]) + @property def has_more_results(self): - """Useful to determine whether to display a `view more results` link.""" + """Returns ``True`` if there are more results than :attr:`result_limit` and ``False`` otherwise.""" return len(self.results) > self.result_limit - @property - def more_results_url(self): - """ - Returns the actual url for more results. This will be encoded - into a querystring for tracking purposes. - """ - raise NotImplementedError + def get_actual_more_results_url(self): + """Returns the actual url for more results. By default, simply returns ``None``.""" + return None + + def get_more_results_querydict(self): + """Returns a :class:`QueryDict` for tracking whether people click on a 'more results' link.""" + url = self.get_actual_more_results_url() + if url: + return make_tracking_querydict(self.search_arg, url) + return None @property - def more_results_querydict(self): - return make_tracking_querydict(self.search_arg, self.more_results_url) + def more_results_url(self): + """Returns a URL which consists of a querystring which, when accessed, will log a :class:`.Click` for the actual URL.""" + qd = self.get_more_results_querydict() + if qd is None: + return None + return "?%s" % qd.urlencode() def __unicode__(self): - return ' '.join(self.__class__.verbose_name.rsplit(' ', 1)[:-1]) + ' results' + return self.verbose_name class DatabaseSearch(BaseSearch): + """Implements :meth:`~BaseSearch.search` and :meth:`get_queryset` methods to handle database queries.""" + #: The model which should be searched by the :class:`DatabaseSearch`. model = None def search(self, limit=None): @@ -261,28 +279,27 @@ class DatabaseSearch(BaseSearch): return self._qs def get_queryset(self): + """Returns a :class:`QuerySet` of all instances of :attr:`model`. This method should be overridden by subclasses to specify how the search should actually be implemented for the model.""" return self.model._default_manager.all() class URLSearch(BaseSearch): - """ - Defines a generic interface for searches that require accessing a - certain url to get search results. - """ + """Defines a generic interface for searches that require accessing a certain url to get search results.""" + #: The base URL which will be accessed to get the search results. search_url = '' + #: The url-encoded query string to be used for fetching search results from :attr:`search_url`. Must have one ``%s`` to contain the search argument. query_format_str = "%s" @property def url(self): - "The URL where the search gets its results." + """The URL where the search gets its results. Composed from :attr:`search_url` and :attr:`query_format_str`.""" return self.search_url + self.query_format_str % urlquote_plus(self.search_arg) - - @property - def more_results_url(self): - "The URL where the users would go to get more results." + + def get_actual_more_results_url(self): return self.url def parse_response(self, response, limit=None): + """Handles the ``response`` from accessing :attr:`url` (with :func:`urllib2.urlopen`) and returns a list of up to ``limit`` results.""" raise NotImplementedError def search(self, limit=None): @@ -290,20 +307,17 @@ class URLSearch(BaseSearch): class JSONSearch(URLSearch): - """ - Makes a GET request and parses the results as JSON. The default - behavior assumes that the return value is a list of results. - """ + """Makes a GET request and parses the results as JSON. The default behavior assumes that the response contains a list of results.""" def parse_response(self, response, limit=None): return json.loads(response.read())[:limit] class GoogleSearch(JSONSearch): + """An example implementation of a :class:`JSONSearch`.""" search_url = "http://ajax.googleapis.com/ajax/services/search/web" - # TODO: Change this template to reflect the app's actual name. - result_template = 'search/googlesearch.html' _cache_timeout = 60 verbose_name = "Google search (current site)" + _more_results_url = None @property def query_format_str(self): @@ -314,6 +328,7 @@ class GoogleSearch(JSONSearch): @property def default_args(self): + """Unquoted default arguments for the :class:`GoogleSearch`.""" return "site:%s" % Site.objects.get_current().domain def parse_response(self, response, limit=None): @@ -341,18 +356,17 @@ class GoogleSearch(JSONSearch): return True return False - @property - def more_results_url(self): + def get_actual_more_results_url(self): return self._more_results_url - def get_result_title(self, result): - return result['titleNoFormatting'] - - def get_result_url(self, result): + def get_actual_result_url(self, result): return result['unescapedUrl'] - def get_result_extra_context(self, result): - return result + def get_result_title(self, result): + return mark_safe(result['titleNoFormatting']) + + def get_result_content(self, result): + return mark_safe(result['content']) registry.register(GoogleSearch) @@ -365,13 +379,22 @@ except: else: __all__ += ('ScrapeSearch', 'XMLSearch',) class ScrapeSearch(URLSearch): - _strainer_args = [] - _strainer_kwargs = {} + """A base class for scrape-style searching, available if :mod:`BeautifulSoup` is installed.""" + #: Arguments to be passed into a :class:`SoupStrainer`. + strainer_args = [] + #: Keyword arguments to be passed into a :class:`SoupStrainer`. + strainer_kwargs = {} @property def strainer(self): + """ + Caches and returns a :class:`SoupStrainer` initialized with :attr:`strainer_args` and :attr:`strainer_kwargs`. This strainer will be used to parse only certain parts of the document. + + .. seealso:: `BeautifulSoup: Improving Performance by Parsing Only Part of the Document `_ + + """ if not hasattr(self, '_strainer'): - self._strainer = SoupStrainer(*self._strainer_args, **self._strainer_kwargs) + self._strainer = SoupStrainer(*self.strainer_args, **self.strainer_kwargs) return self._strainer def parse_response(self, response, limit=None): @@ -381,18 +404,21 @@ else: def parse_results(self, results): """ - Provides a hook for parsing the results of straining. This - has no default behavior because the results absolutely - must be parsed to properly extract the information. - For more information, see http://www.crummy.com/software/BeautifulSoup/documentation.html#Improving%20Memory%20Usage%20with%20extract + Provides a hook for parsing the results of straining. This has no default behavior and must be implemented by subclasses because the results absolutely must be parsed to properly extract the information. + + .. seealso:: `BeautifulSoup: Improving Memory Usage with extract `_ """ raise NotImplementedError class XMLSearch(ScrapeSearch): - _self_closing_tags = [] + """A base class for searching XML results.""" + #: Self-closing tag names to be used when interpreting the XML document + #: + #: .. seealso:: `BeautifulSoup: Parsing XML `_ + self_closing_tags = [] def parse_response(self, response, limit=None): strainer = self.strainer - soup = BeautifulStoneSoup(response, selfClosingTags=self._self_closing_tags, parseOnlyThese=strainer) + soup = BeautifulStoneSoup(response, selfClosingTags=self.self_closing_tags, parseOnlyThese=strainer) return self.parse_results(soup.findAll(recursive=False, limit=limit)) \ No newline at end of file