Source code for internetarchivepdf.scandata

# archive-pdf-tools
# Copyright (C) 2020-2021, Internet Archive
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# Author: Merlijn Boris Wolf Wajer <merlijn@archive.org>

import xmltodict
from collections import OrderedDict


def scandata_xml_get_skip_pages(xml_file):
    scandata = xmltodict.parse(open(xml_file, 'rb'))

    skip = []

    for idx in range(len(scandata['book']['pageData']['page'])):
        try:
            add_to_access_format = scandata['book']['pageData']['page'][idx]['addToAccessFormats']
            if add_to_access_format == 'false':
                skip.append(idx)
        except KeyError:
            pass

    return skip


def scandata_xml_get_page_numbers(xml_file):
    scandata = xmltodict.parse(open(xml_file, 'rb'))

    res = []

    pages = scandata['book']['pageData']['page']

    # If there is just one page, pages is not a list.
    if not isinstance(pages, list):
        pages = [pages]
    for idx in range(len(pages)):
        try:
            add_to_access_format = pages[idx]['addToAccessFormats']
            if add_to_access_format == 'false':
                continue
        except KeyError:
            pass

        pno = pages[idx].get('pageNumber', None)
        res.append(pno)

    return res


def scandata_xml_get_dpi_per_page(xml_file):
    scandata = xmltodict.parse(open(xml_file, 'rb'))

    res = []

    pages = scandata['book']['pageData']['page']

    # If there is just one page, pages is not a list.
    if not isinstance(pages, list):
        pages = [pages]
    for idx in range(len(pages)):
        try:
            add_to_access_format = pages[idx]['addToAccessFormats']
            if add_to_access_format == 'false':
                continue
        except KeyError:
            pass

        ppi = pages[idx].get('ppi', None)
        res.append(ppi)

    return res


def scandata_xml_get_document_dpi(xml_file):
    scandata = xmltodict.parse(open(xml_file, 'rb'))

    doc_ppi = scandata['book']['bookData'].get('dpi', None)

    if doc_ppi is not None:
        try:
            doc_ppi = int(doc_ppi)
        except (ValueError):
            return None

    return doc_ppi




def scandata_xml_get_toc(xml_file):
    """
    Returns a table of contents given a parsed scandata.xml

    Args:

    * scandata: Parsed scandata as returned by scandata_parse

    Returns:

    * List of dict describing the table of contents:
      Indexes of pages that match a specific page type:
      [{'title': 'The beginning', 'level': 1, 'label': None, 'leaf': 2}, ...]
      (``list of dict``)

    Might raise KeyError in case the scandata is invalid
    """
    scandata = xmltodict.parse(open(xml_file, 'rb'))

    toc = []

    pages = scandata['book']['pageData']['page']

    # If there is just one page, pages is not a list.
    if not isinstance(pages, list):
        pages = [pages]

    accessible_count = 0
    for idx in range(len(pages)):
        leaf_num = pages[idx]['@leafNum']
        page_data = pages[idx]['pageType']

        # Do we want to filter based on specific page types?
        # Let's not for now, since we might want to allow many types
        if isinstance(page_data, (dict, OrderedDict)):
            # Let's see what we have

            if '@title' in page_data:
                title = page_data.get('@title')
                level = int(page_data.get('@level', 1))
                label = page_data.get('@label', None)

            toc.append({'title': title, 'level': level, 'label': label,
                        'leaf': leaf_num, 'accessible-page': accessible_count})

        add_to_access_format = pages[idx].get('addToAccessFormats', 'true') == 'true'
        if add_to_access_format:
            accessible_count += 1

    return toc