reporting-engine/report_py3o/py3o_parser.py

# -*- coding: utf-8 -*-
# Copyright 2013 XCG Consulting (http://odoo.consulting)
# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl)
from cStringIO import StringIO
import json
import pkg_resources
import os
import sys
from base64 import b64decode
import requests
from tempfile import NamedTemporaryFile
from py3o.template.helpers import Py3oConvertor
from py3o.template import Template
from py3o.formats import Formats

from openerp import _
from openerp import exceptions
from openerp.report.report_sxw import report_sxw
from openerp import registry


_extender_functions = {}


class TemplateNotFound(Exception):
    pass


def py3o_report_extender(report_xml_id=None):
    """
    A decorator to define function to extend the context sent to a template.
    This will be called at the creation of the report.
    The following arguments will be passed to it:
        - ir_report: report instance
        - localcontext: The context that will be passed to the report engine
    If no report_xml_id is given the extender is registered for all py3o
    reports
    Idea copied from CampToCamp report_webkit module.

    :param report_xml_id: xml id of the report
    :return: a decorated class
    """
    global _extender_functions

    def fct1(fct):
        _extender_functions.setdefault(report_xml_id, []).append(fct)
        return fct
    return fct1


@py3o_report_extender()
def defautl_extend(report_xml, localcontext):
    # add the base64decode function to be able do decode binary fields into
    # the template
    localcontext['b64decode'] = b64decode


class Py3oParser(report_sxw):
    """Custom class that use Py3o to render libroffice reports.
        Code partially taken from CampToCamp's webkit_report."""

    def get_template(self, report_obj):
        """private helper to fetch the template data either from the database
        or from the default template file provided by the implementer.

        ATM this method takes a report definition recordset
        to try and fetch the report template from database. If not found it
        will fallback to the template file referenced in the report definition.

        @param report_obj: a recordset representing the report defintion
        @type report_obj: openerp.model.recordset instance

        @returns: string or buffer containing the template data

        @raises: TemplateNotFound which is a subclass of
        openerp.exceptions.DeferredException
        """

        tmpl_data = None

        if report_obj.py3o_template_id and report_obj.py3o_template_id.id:
            # if a user gave a report template
            tmpl_data = b64decode(
                report_obj.py3o_template_id.py3o_template_data
            )

        elif report_obj.py3o_template_fallback:
            tmpl_name = report_obj.py3o_template_fallback
            flbk_filename = None
            if report_obj.module:
                # if the default is defined
                flbk_filename = pkg_resources.resource_filename(
                    "openerp.addons.%s" % report_obj.module,
                    tmpl_name,
                )
            elif os.path.isabs(tmpl_name):
                # It is an absolute path
                flbk_filename = os.path.normcase(os.path.normpath(tmpl_name))
            if flbk_filename and os.path.exists(flbk_filename):
                # and it exists on the fileystem
                with open(flbk_filename, 'r') as tmpl:
                    tmpl_data = tmpl.read()

        if tmpl_data is None:
            # if for any reason the template is not found
            raise TemplateNotFound(
                _(u'No template found. Aborting.'),
                sys.exc_info(),
            )

        return tmpl_data

    def _extend_parser_context(self, parser_instance, report_xml):
        # add default extenders
        for fct in _extender_functions.get(None, []):
            fct(report_xml, parser_instance.localcontext)
        # add extenders for registered on the template
        xml_id = report_xml.get_external_id().get(report_xml.id)
        if xml_id in _extender_functions:
            for fct in _extender_functions[xml_id]:
                fct(report_xml, parser_instance.localcontext)

    def create_single_pdf(self, cr, uid, ids, data, report_xml, context=None):
        """ Overide this function to generate our py3o report
        """
        if report_xml.report_type != 'py3o':
            return super(Py3oParser, self).create_single_pdf(
                cr, uid, ids, data, report_xml, context=context
            )

        parser_instance = self.parser(cr, uid, self.name2, context=context)
        parser_instance.set_context(
            self.getObjects(cr, uid, ids, context),
            data, ids, report_xml.report_type
        )
        self._extend_parser_context(parser_instance, report_xml)

        tmpl_data = self.get_template(report_xml)

        in_stream = StringIO(tmpl_data)
        out_stream = StringIO()
        template = Template(in_stream, out_stream)
        localcontext = parser_instance.localcontext
        if report_xml.py3o_is_local_fusion:
            template.render(localcontext)
            input = out_stream.getvalue()
        else:
            expressions = template.get_all_user_python_expression()
            py_expression = template.convert_py3o_to_python_ast(expressions)
            convertor = Py3oConvertor()
            data_struct = convertor(py_expression)
            input = data_struct.render(localcontext)

        filetype = report_xml.py3o_fusion_filetype
        is_native = Formats().get_format(filetype).native
        if is_native:
            res = input
        else:  # Call py3o.server to render the template in the desired format
            in_stream.seek(0)
            files = {
                'tmpl_file': in_stream,
            }
            fields = {
                "targetformat": filetype.fusion_ext,
                "datadict": json.dumps(input),
                "image_mapping": "{}",
            }
            r = requests.post(
                report_xml.py3o_server_id.url, data=fields, files=files)
            if r.status_code != 200:
                # server says we have an issue... let's tell that to enduser
                raise exceptions.Warning(
                    _('Fusion server error %s') % r.text,
                )

            # Here is a little joke about Odoo
            # we do nice chunked reading from the network...
            chunk_size = 1024
            with NamedTemporaryFile(
                    suffix=filetype.human_ext,
                    prefix='py3o-template-'
            ) as fd:
                for chunk in r.iter_content(chunk_size):
                    fd.write(chunk)
                fd.seek(0)
                # ... but odoo wants the whole data in memory anyways :)
                res = fd.read()

        return res, "." + filetype

    def create(self, cr, uid, ids, data, context=None):
        """ Override this function to handle our py3o report
        """
        pool = registry(cr.dbname)
        ir_action_report_obj = pool['ir.actions.report.xml']
        report_xml_ids = ir_action_report_obj.search(
            cr, uid, [('report_name', '=', self.name[7:])], context=context
        )
        if not report_xml_ids:
            return super(Py3oParser, self).create(
                cr, uid, ids, data, context=context
            )

        report_xml = ir_action_report_obj.browse(
            cr, uid, report_xml_ids[0], context=context
        )

        result = self.create_source_pdf(
            cr, uid, ids, data, report_xml, context
        )

        if not result:
            return False, False
        return result