''' functionality outline for a book data connector ''' from abc import ABC, abstractmethod from dateutil import parser import pytz import requests from fedireads import models class AbstractConnector(ABC): ''' generic book data connector ''' def __init__(self, identifier): # load connector settings info = models.Connector.objects.get(identifier=identifier) self.connector = info self.book_mappings = {} self.base_url = info.base_url self.books_url = info.books_url self.covers_url = info.covers_url self.search_url = info.search_url self.key_name = info.key_name self.max_query_count = info.max_query_count self.name = info.name self.local = info.local self.id = info.id def is_available(self): ''' check if you're allowed to use this connector ''' if self.max_query_count is not None: if self.connector.query_count >= self.max_query_count: return False return True def search(self, query): ''' free text search ''' resp = requests.get( '%s%s' % (self.search_url, query), headers={ 'Accept': 'application/json; charset=utf-8', }, ) if not resp.ok: resp.raise_for_status() data = resp.json() results = [] for doc in data['docs'][:10]: results.append(self.format_search_result(doc)) return results def create_book(self, key, data, model): ''' create a work or edition from data ''' # we really would rather use an existing book than make a new one match = match_from_mappings(data, self.key_mappings) if match: if not isinstance(match, model): if type(match).__name__ == 'Edition': return match.parent_work else: return match.default_edition return match kwargs = { self.key_name: key, 'title': data['title'], 'connector': self.connector } book = model.objects.create(**kwargs) return self.update_book_from_data(book, data) def update_book_from_data(self, book, data): ''' simple function to save data to a book ''' update_from_mappings(book, data, self.book_mappings) book.save() return book @abstractmethod def format_search_result(self, search_result): ''' create a SearchResult obj from json ''' @abstractmethod def get_or_create_book(self, book_id): ''' request and format a book given an identifier ''' # return book model obj @abstractmethod def expand_book_data(self, book): ''' get more info on a book ''' @abstractmethod def get_or_create_author(self, book_id): ''' request and format a book given an identifier ''' # return book model obj @abstractmethod def update_book(self, book_obj, data=None): ''' sync a book with the canonical remote copy ''' # return book model obj def update_from_mappings(obj, data, mappings): ''' assign data to model with mappings ''' noop = lambda x: x mappings['authors'] = ('', noop) mappings['parent_work'] = ('', noop) for (key, value) in data.items(): formatter = None if key in mappings: key, formatter = mappings[key] if not formatter: formatter = noop if key == 'id': continue if has_attr(obj, key): obj.__setattr__(key, formatter(value)) return obj def match_from_mappings(data, mappings): ''' try to find existing copies of this book using various keys ''' keys = [ ('openlibrary_key', models.Book), ('librarything_key', models.Book), ('goodreads_key', models.Book), ('lccn', models.Work), ('isbn_10', models.Edition), ('isbn_13', models.Edition), ('oclc_number', models.Edition), ('asin', models.Edition), ] noop = lambda x: x for key, model in keys: formatter = None if key in mappings: key, formatter = mappings[key] if not formatter: formatter = noop value = data.get(key) if not value: continue value = formatter(value) match = model.objects.select_subclasses().filter( **{key: value}).first() if match: return match def has_attr(obj, key): ''' helper function to check if a model object has a key ''' try: return hasattr(obj, key) except ValueError: return False def get_date(date_string): ''' helper function to try to interpret dates ''' try: return pytz.utc.localize(parser.parse(date_string)) except ValueError: return None class SearchResult: ''' standardized search result object ''' def __init__(self, title, key, author, year): self.title = title self.key = key self.author = author self.year = year def __repr__(self): return "".format( self.key, self.title, self.author)