# -*- coding: utf-8 -*-
##############################################################################
#
#    OpenERP, Open Source Management Solution
#    Copyright (C) 2004-2009 Tiny SPRL (<http://tiny.be>).
#
#    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/>.
#
##############################################################################

import itertools

from osv import fields,osv
from osv.orm import except_orm
import tools

class ir_attachment(osv.osv):
    def check(self, cr, uid, ids, mode, context=None, values=None):
        """Restricts the access to an ir.attachment, according to referred model
        In the 'document' module, it is overriden to relax this hard rule, since
        more complex ones apply there.
        """
        if not ids:
            return
        res_ids = {}
        if ids:
            if isinstance(ids, (int, long)):
                ids = [ids]
            cr.execute('SELECT DISTINCT res_model, res_id FROM ir_attachment WHERE id = ANY (%s)', (ids,))
            for rmod, rid in cr.fetchall():
                if not (rmod and rid):
                    continue
                res_ids.setdefault(rmod,set()).add(rid)
        if values:
            if 'res_model' in values and 'res_id' in values:
                res_ids.setdefault(values['res_model'],set()).add(values['res_id'])

        ima = self.pool.get('ir.model.access')
        for model, mids in res_ids.items():
            # ignore attachments that are not attached to a resource anymore when checking access rights
            # (resource was deleted but attachment was not)
            mids = self.pool.get(model).exists(cr, uid, mids)
            ima.check(cr, uid, model, mode)
            self.pool.get(model).check_access_rule(cr, uid, mids, mode, context=context)

    def search(self, cr, uid, args, offset=0, limit=None, order=None,
            context=None, count=False):
        ids = super(ir_attachment, self).search(cr, uid, args, offset=offset,
                                                limit=limit, order=order,
                                                context=context, count=False)
        if not ids:
            if count:
                return 0
            return []

        # For attachments, the permissions of the document they are attached to
        # apply, so we must remove attachments for which the user cannot access
        # the linked document.
        targets = super(ir_attachment,self).read(cr, uid, ids, ['id', 'res_model', 'res_id'])
        model_attachments = {}
        for target_dict in targets:
            if not (target_dict['res_id'] and target_dict['res_model']):
                continue
            # model_attachments = { 'model': { 'res_id': [id1,id2] } }
            model_attachments.setdefault(target_dict['res_model'],{}).setdefault(target_dict['res_id'],set()).add(target_dict['id'])

        # To avoid multiple queries for each attachment found, checks are
        # performed in batch as much as possible.
        ima = self.pool.get('ir.model.access')
        for model, targets in model_attachments.iteritems():
            if not ima.check(cr, uid, model, 'read', False):
                # remove all corresponding attachment ids
                for attach_id in itertools.chain(*targets.values()):
                    ids.remove(attach_id)
                continue # skip ir.rule processing, these ones are out already

            # filter ids according to what access rules permit
            target_ids = targets.keys()
            allowed_ids = self.pool.get(model).search(cr, uid, [('id', 'in', target_ids)], context=context)
            disallowed_ids = set(target_ids).difference(allowed_ids)
            for res_id in disallowed_ids:
                for attach_id in targets[res_id]:
                    ids.remove(attach_id)
        if count:
            return len(ids)
        return ids

    def read(self, cr, uid, ids, fields_to_read=None, context=None, load='_classic_read'):
        self.check(cr, uid, ids, 'read', context=context)
        return super(ir_attachment, self).read(cr, uid, ids, fields_to_read, context, load)

    def write(self, cr, uid, ids, vals, context=None):
        self.check(cr, uid, ids, 'write', context=context, values=vals)
        return super(ir_attachment, self).write(cr, uid, ids, vals, context)

    def copy(self, cr, uid, id, default=None, context=None):
        self.check(cr, uid, [id], 'write', context=context)
        return super(ir_attachment, self).copy(cr, uid, id, default, context)

    def unlink(self, cr, uid, ids, context=None):
        self.check(cr, uid, ids, 'unlink', context=context)
        return super(ir_attachment, self).unlink(cr, uid, ids, context)

    def create(self, cr, uid, values, context=None):
        self.check(cr, uid, [], mode='create', context=context, values=values)
        return super(ir_attachment, self).create(cr, uid, values, context)

    def action_get(self, cr, uid, context=None):
        return self.pool.get('ir.actions.act_window').for_xml_id(
            cr, uid, 'base', 'action_attachment', context=context)

    def _name_get_resname(self, cr, uid, ids, object, method, context):
        data = {}
        for attachment in self.browse(cr, uid, ids, context=context):
            model_object = attachment.res_model
            res_id = attachment.res_id
            if model_object and res_id:
                model_pool = self.pool.get(model_object)
                res = model_pool.name_get(cr,uid,[res_id],context)
                res_name = res and res[0][1] or False
                if res_name:
                    field = self._columns.get('res_name',False)
                    if field and len(res_name) > field.size:
                        res_name = res_name[:field.size-3] + '...' 
                data[attachment.id] = res_name
            else:
                data[attachment.id] = False
        return data

    _name = 'ir.attachment'
    _columns = {
        'name': fields.char('Attachment Name',size=256, required=True),
        'datas': fields.binary('Data'),
        'datas_fname': fields.char('Filename',size=256),
        'description': fields.text('Description'),
        'res_name': fields.function(_name_get_resname, type='char', size=128,
                string='Resource Name', store=True),
        'res_model': fields.char('Resource Object',size=64, readonly=True,
                help="The database object this attachment will be attached to"),
        'res_id': fields.integer('Resource ID', readonly=True,
                help="The record id this is attached to"),
        'url': fields.char('Url', size=512, oldname="link"),
        'type': fields.selection(
                [ ('url','URL'), ('binary','Binary'), ],
                'Type', help="Binary File or external URL", required=True, change_default=True),

        'create_date': fields.datetime('Date Created', readonly=True),
        'create_uid':  fields.many2one('res.users', 'Owner', readonly=True),
        'company_id': fields.many2one('res.company', 'Company', change_default=True),
    }

    _defaults = {
        'type': 'binary',
        'company_id': lambda s,cr,uid,c: s.pool.get('res.company')._company_default_get(cr, uid, 'ir.attachment', context=c),
    }

    def _auto_init(self, cr, context=None):
        super(ir_attachment, self)._auto_init(cr, context)
        cr.execute('SELECT indexname FROM pg_indexes WHERE indexname = %s', ('ir_attachment_res_idx',))
        if not cr.fetchone():
            cr.execute('CREATE INDEX ir_attachment_res_idx ON ir_attachment (res_model, res_id)')
            cr.commit()

ir_attachment()


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