med/media/forms.py

# -*- mode: python; coding: utf-8 -*-
# Copyright (C) 2017-2019 by BDE ENS Paris-Saclay
# SPDX-License-Identifier: GPL-3.0-or-later

import json
import urllib.request

from django.forms import ModelForm

from .scraper import BedetequeScraper


class MediaAdminForm(ModelForm):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        isbn_field = self.fields.get('isbn')
        if isbn_field:
            isbn_field.widget.template_name = "media/isbn_button.html"
            isbn_field.widget.attrs.update({'autofocus': 'autofocus'})

    def download_data_bedeteque(self, isbn):
        """
        Download data from bedeteque
        :return True if success
        """
        scraper = BedetequeScraper()
        r = scraper.search_by_isbn(isbn)
        if not r:
            return False
        # If results, then take the most accurate
        data = scraper.scrap_bd_info(r[0])
        self.cleaned_data.update(data)
        return True

    def download_data_openlibrary(self, isbn):
        """
        Download data from openlibrary
        :return True if success
        """
        api_url = "https://openlibrary.org/api/books?bibkeys=ISBN:{}" \
                  "&format=json&jscmd=data".format(isbn)
        with urllib.request.urlopen(api_url) as url:
            data = json.loads(url.read().decode())
        if data and data['ISBN:' + isbn]:
            data = data['ISBN:' + isbn]
            if 'url' in data:
                # Fill the data
                self.cleaned_data['external_url'] = data['url']
                if 'title' in data:
                    self.cleaned_data['title'] = data['title']
                if 'subtitle' in data:
                    self.cleaned_data['subtitle'] = data['subtitle']
                if 'number_of_pages' in data:
                    self.cleaned_data['number_of_pages'] = \
                        data['number_of_pages']
                return True
        return False

    def clean(self):
        """
        If user fetch ISBN data, then download data before validating the form
        """
        super().clean()

        # TODO implement authors, side_identifier
        if "_continue" in self.request.POST:
            isbn = self.cleaned_data.get('isbn')
            if isbn:
                # ISBN is present, try with bedeteque
                scrap_result = self.download_data_bedeteque(isbn)
                if not scrap_result:
                    # Try with OpenLibrary
                    self.download_data_openlibrary(isbn)

        return self.cleaned_data

    def _clean_fields(self):
        for name, field in self.fields.items():
            # value_from_datadict() gets the data from the data dictionaries.
            # Each widget type knows how to retrieve its own data, because some
            # widgets split data over several HTML fields.
            if field.disabled:
                value = self.get_initial_for_field(field, name)
            else:
                value = field.widget.value_from_datadict(self.data, self.files, self.add_prefix(name))
            from django.core.exceptions import ValidationError
            try:
                # We don't want to check a field when we enter an ISBN.
                if "_continue" not in self.request.POST or not self.cleaned_data.get('isbn'):
                    value = field.clean(value)
                self.cleaned_data[name] = value
                if hasattr(self, 'clean_%s' % name):
                    value = getattr(self, 'clean_%s' % name)()
                    self.cleaned_data[name] = value
            except ValidationError as e:
                self.add_error(name, e)