在odoo8的many2many字段中附加新文档时，添加已删除的文档

如何解决在odoo8的many2many字段中附加新文档时，添加已删除的文档

我们正在使用 sync_mail_multi_attach_ext（多重附件上传器模块），当我上传文档并删除并再次上传其他文档时，此模块小部件已在odoo 8的many2many字段中使用添加。如何从将已删除的文档添加到当前文档中来解决该问题。

'session.web.form.FieldMany2ManyBinaryMultiFiles.include({
        on_file_change: function (event) {
            event.stopPropagation();
            var self = this;
            var $target = $(event.target);
            if ($target.val() !== '') {
                var filename = $target.val().replace(/.*[\\\/]/,'');
                // don't uplode more of one file in same time
                if (self.data[0] && self.data[0].upload ) {
                    return false;
                }
                for (var id in this.get('value')) {
                    // if the files exits,delete the file before upload (if it's a new file)
                    if (self.data[id] && (self.data[id].filename || self.data[id].name) == filename && !self.data[id].no_unlink ) {
                        self.ds_file.unlink([id]);
                    }
                }

                // block UI or not
                if(this.node.attrs.blockui>0) {
                    instance.web.blockUI();
                }

                // TODO : unactivate send on wizard and form
                _.each($target[0].files,function(file){
                    var querydata = new FormData();
                    querydata.append('callback','oe_fileupload_temp2');
                    querydata.append('ufile',file);
                    querydata.append('model','hr.documents');
                    querydata.append('id','0');
                    querydata.append('multi','true');
                    $.ajax({
                        url: '/web/binary/upload_attachment',type: 'POST',data: querydata,cache: false,processData: false,contentType: false,success: function(id){
                            self.data[id] = {
                                'id': parseInt(id),'name': file.name,'filename': filename.name,'url': '','upload': false
                            };
                        },});

                });
                // submit file
                this.$('form.oe_form_binary_form').submit();
            }
        },'