I'm currently adapting the hr module to meet my company's requirement.

I've added two fields to the hr.holidays model.

When displaying the tree view, the js client doesn't render the table properly.

I also get some warning in the log (WARNING openerp.models: hr.holidays.read() with unknown field 'False')

When I look at the rpc request, I can see where the problem is : there's a 13th column called "false" but I don't know why it's there.

Here's the whole request : | Edit : Python code is below | I'm fairly new to Odoo and I don't know where to start looking, so any clue is welcomed !

{
  "jsonrpc": "2.0",
  "method": "call",
  "params": {
    "model": "hr.holidays",
    "method": "read",
    "args": [
      [
        12974
      ],
      [
        "holiday_status_id",
        "employee_id",
        "user_id",
        "date_from",
        "holiday_type",
        "state",
        "manager_id",
        "type",
        "department_id",
        "date_to",
        "category_id",
        "name",
        "number_of_days",
        false
      ]
    ],
    "kwargs": {
      "context": {
        "lang": "en_US",
        "tz": "Europe\/Brussels",
        "uid": 1,
        "params": {
          "action": 1867
        },
        "active_model": "hr.holidays"
      }
    }
  },
 "id": 793485475
}

Edit : My python code 

from openerp import models,fields,api, _, workflow
from datetime import datetime, timedelta
from openerp.exceptions import ValidationError
from openerp.osv import osv
class hr_holidays(models.Model):
    _inherit = "hr.holidays"
   
    @api.multi  
    def _get_employee(self):
        employee = self.env['hr.employee'].search([('user_id', '=', self._uid)])
        if employee[0]:
            return employee[0] 
        else:
            return None
    
    @api.multi
    def _get_employee_id(self):
        employee = self.env['hr.employee'].search([('user_id', '=', self._uid)])
        
        if employee[0]:
            return employee[0].id 
        else:
            return None        
    
    #select automatically the good type depending on remaining days
    @api.model
    def _get_default_status_id(self, requested_days):
        employee = self._get_employee()
        
        #check by type of holidays if user has always
        types = self.env["hr.holidays.status"].search([], order='count desc,sequence')
        
        if not types:
            return None
        
        for holiday_type in types:
            if holiday_type.count:
                leave_days = holiday_type.get_days(employee.id)[holiday_type.id]
                if leave_days['remaining_leaves'] >= requested_days and leave_days['virtual_remaining_leaves'] >= requested_days:
                    return holiday_type.id
        return types[0].id                
    def onchange_type(self, cr, uid, ids, holiday_type):
        result = {}
        manager_group_id = self.pool.get('ir.model.data').get_object_reference(cr, uid, 'base','group_hr_manager')[1]
        manager_group = self.pool.get('res.groups').browse(cr, uid, manager_group_id)
        
        if uid in manager_group.users.ids:
            return result
        
        if holiday_type == 'employee':
            employee_id = self.pool.get('hr.employee').search(cr, uid, [('user_id', '=', uid)])[0]
            
            if employee_id:            
                result['value'] = {'employee_id': employee_id}
                
        return result
    
    def onchange_date_from(self, cr, uid, ids, date_to, date_from, employee_id):
        try:
            result = super(hr_holidays,self).onchange_date_from(cr, uid, ids, date_to, date_from)
        except osv.except_osv:
            #bypass warning if start date > end date
            return {'value':{'number_of_days_temp': 0}}
        if date_to and date_from:
            diff_day = self._get_number_of_days_elneo(cr, uid, date_from, date_to, employee_id)
            result['value'] = {
                'number_of_days_temp': diff_day
            }
            return result
        
        result['value'] = {
            'number_of_days_temp': 0,
        }
        return result
    
    def onchange_date_to(self, cr, uid, ids, date_to, date_from, employee_id):
        try:
            result = super(hr_holidays,self).onchange_date_to(cr, uid, ids, date_to, date_from)
        except osv.except_osv:
            #by pass warning if start date > end date
            return {'value':{'number_of_days_temp': 0}}
        
        if date_to and date_from:
            diff_day = self._get_number_of_days_elneo(cr, uid, date_from, date_to, employee_id)
            result['value'] = {
                'number_of_days_temp': diff_day
            }
            return result
        result['value'] = {
            'number_of_days_temp': 0,
        }
        return result
    
    @api.onchange('number_of_days_temp')
    def onchange_number_of_days_temp(self):
        res = {}
        new_holiday_status = self._get_default_status_id(self.number_of_days_temp)
        if not new_holiday_status:
            return res
        '''if self.holiday_status_id and self.holiday_status_id.id != new_holiday_status:
            res = {'warning':{'title':'Warning','message':'Holiday type has changed !'}}'''
        self.holiday_status_id = new_holiday_status
        return res
        
    #compute number of days based on working days and leaves already encoded
    @api.model
    def _get_number_of_days_elneo(self, date_from, date_to, employee_id):
        DATETIME_FORMAT = "%Y-%m-%d %H:%M:%S"
        INCREMENT=0.5
        from_date = datetime.strptime(date_from, DATETIME_FORMAT)
        to_date = datetime.strptime(date_to, DATETIME_FORMAT)
        
        
        #build array of each days of current holidays
        current_holidays = []
        current_date = from_date
        if(to_date.strftime("%H%M") > "1200"):
            to_date=to_date.replace(hour=23,minute=59)
        while current_date <= to_date:
            date_without_hours = current_date.date()
            if current_date.strftime("%H%M") > "1200":
                period = 1
            else:
                period = 0
            current_holidays.append((date_without_hours,period))
            current_date = current_date+timedelta(days=INCREMENT) 
            
        
        #find holidays already encoded and subtract days already encoded, in the current interval
        previous_holidays_objs = self.search([('state','=','validate'),('type','=','remove'),('employee_id','=',employee_id),
                '|','&',('date_from','>=',datetime.strftime(from_date, DATETIME_FORMAT)),('date_from','<=',datetime.strftime(to_date, DATETIME_FORMAT)),
                '|','&',('date_to','>=',datetime.strftime(from_date, DATETIME_FORMAT)),('date_to','<=',datetime.strftime(to_date, DATETIME_FORMAT)),
                '&',('date_from','<=',datetime.strftime(from_date, DATETIME_FORMAT)),('date_to','>=',datetime.strftime(to_date, DATETIME_FORMAT))
        ])
        
        #build dict of previous holidays
        previous_holidays = set()
        for previous_holidays_obj in previous_holidays_objs:
            current_date = datetime.strptime(previous_holidays_obj.date_from, DATETIME_FORMAT)
            date_to = datetime.strptime(previous_holidays_obj.date_to, DATETIME_FORMAT)
            if(date_to.strftime("%H%M") > "1200"):
                date_to=date_to.replace(hour=23,minute=59)
            while current_date < date_to:
                date_without_hours = current_date.date()
                if current_date.strftime("%H%M") > "1200":
                    period = 1
                else:
                    period = 0
                previous_holidays.add((date_without_hours,period))
                current_date = current_date+timedelta(days=INCREMENT)
                
        #browse array of current holidays and add one day only if date is not in previous holidays array
        number_of_days = 0
        for day_part in current_holidays:
            if ((day_part not in previous_holidays) and (day_part[0].strftime('%w') not in ['0','6'])):                
                    number_of_days = number_of_days+INCREMENT          
        
        return number_of_days
        
        ####################
        
        removed_days = set() #set of days already used by other holidays
        for previous_holiday in previous_holidays:
            current_date = from_date
            while (current_date < to_date):
                current_date_str = datetime.strftime(current_date, DATETIME_FORMAT)
                if (current_date_str >= previous_holiday.date_from) and (current_date_str <= previous_holiday.date_to) and (current_date.strftime('%w') not in ['0','6']):
                    removed_days.add(current_date)
                        
                current_date = current_date+timedelta(days=INCREMENT)
                
            if((current_date.strftime("%d%m%Y") == to_date.strftime("%d%m%Y")) & ((to_date.strftime("%H%M") > "1200") | (current_date.strftime("%H%M") > "1200"))):
                removed_days.add(current_date)
                
           
                
        days_to_remove = len(removed_days) * INCREMENT  
        
        #count days of holidays
        number_of_days = 0.0
        current_date = from_date
      
        
        while ((current_date < to_date)):
            if current_date.strftime('%w') not in ['0','6']:
                number_of_days = float(number_of_days+INCREMENT)
           
            current_date = current_date+timedelta(days=INCREMENT)
            
        if((current_date.strftime("%d%m%Y") == to_date.strftime("%d%m%Y")) & (to_date.strftime("%H%M") > "1200")):
            number_of_days = float(number_of_days+INCREMENT)
        
        return number_of_days-days_to_remove;
    
    #set manager as manager of department.  
    def set_manager(self):
        if self.department_id and self.department_id.manager_id: # bien employee_id
            self.manager_id  = self.department_id.manager_id.id
        else:
            self.manager_id  = 20
        self.manager_id2 = 20 
    @api.onchange('department_id')
    def onchange_department(self):
        self.set_manager()
    #say if current user is in hr manager group 
    @api.model
    def uid_hr_manager(self):
        manager_group_id = self.env['ir.model.data'].get_object_reference('base','group_hr_manager')[1]
        manager_group = self.env['res.groups'].browse(manager_group_id)
        
        if self._uid in manager_group.users.ids:
            return True
        return False
           
    @api.multi
    def holidays_confirm(self):
        res = super(hr_holidays, self).holidays_confirm()
        for holiday in self:
            holiday.set_manager()
        return res
    
    #limit first approval to manager or hr managers
    @api.multi
    def holidays_first_validate(self):
        res = super(hr_holidays, self).holidays_first_validate()
        for holiday in self:
            if holiday.manager_id and holiday.manager_id.user_id and holiday.manager_id.user_id.id != self._uid and not self.uid_hr_manager():
                if holiday.manager_id:
                    raise ValidationError(_('Only %s or hr managers can approve this holiday !')%holiday.manager_id.name)
                else:
                    raise ValidationError(_('Only hr managers can approve this holiday !'))
        return res
    
    #limit second approval aka validation to hr manager
    @api.multi
    def holidays_validate(self):
        res = super(hr_holidays, self).holidays_validate()
        if not self.uid_hr_manager():
            raise ValidationError(_('Only hr managers can approve this holiday !'))
        return res
    
    #override _check_date function to allow overlap of 2 leaves on the same date with different types
    @api.multi 
    def _check_date(self):
        for holiday in self:
            domain = [
                ('date_from', '<=', holiday.date_to),
                ('date_to', '>=', holiday.date_from),
                ('employee_id', '=', holiday.employee_id.id),
                ('id', '!=', holiday.id),
                ('state', 'not in', ['cancel', 'refuse']),
                ('holiday_status_id','=',holiday.holiday_status_id.id), 
                ('type','=',holiday.type)
            ]
            nholidays = self.search_count(domain)
            if nholidays:
                return False
        return True
    
    #change constraint to bypass warning
    _constraints = [
        (_check_date, 'You can not have 2 leaves that overlaps on same day!', ['date_from','date_to']),
    ] 
    
    @api.depends('date_from')
    @api.one
    def _get_year(self):
        for holiday in self:
            if holiday.date_from:
                holiday.year = holiday.date_from[0:4]
            else:
                holiday.year = ''
    
    year = fields.Char(string="Year", compute='_get_year', store=True)
    
    @api.model
    def default_get(self, fields):
        res = super(hr_holidays, self).default_get(fields)
        for field in fields:
            if field == 'name':
                res['name'] = _('Holidays')
            if field == 'holiday_status_id':
                default_status = self._get_default_status_id(1)
                if default_status:
                    res['holiday_status_id'] = self._get_default_status_id(1)
            if field == 'date_from':
                if 'date_from' in res:
                    res['date_from'] = res['date_from'][0:10]+' 07:00:00'
                else:
                    res['date_from'] = datetime.now().strftime('%Y-%m-%d 07:00:00')
            if field == 'date_to':
                if 'date_to' in res:
                    res['date_to'] = res['date_to'][0:10]+' 15:45:00'
                else:
                    res['date_to'] = datetime.now().strftime('%Y-%m-%d 15:45:00')
            if field == 'employee_id':
                res['employee_id'] = self._get_employee_id()
        return res 
    
    #display notification number on menu item only for holidays on which we must do an action 
    @api.model
    def _needaction_domain_get(self):
        dom = super(hr_holidays, self)._needaction_domain_get()
        #dom.extend(['|',('manager_user_id','=',self._uid),('manager_user_id2','=',self._uid)])
        dom.extend(['|',('manager_id','=',self._uid),('manager_id2','=',self._uid)])
        return dom
    
#add fields to automate selection of good holiday type
class hr_holidays_status(models.Model):
    _inherit = "hr.holidays.status"
    _order = 'sequence'
    
    sequence = fields.Integer("Sequence", help='Sequence is used to choose the first type with remaining days as default type.') 
    count = fields.Boolean("Count", help="First type with 'count' and with several remaining days will be used as default type ")
    
    #display leaves taken and max even if holiday type is limited 
    def name_get(self, cr, uid, ids, context=None):
        if context is None:
            context = {}
        if not context.get('employee_id',False):
            # leave counts is based on employee_id, would be inaccurate if not based on correct employee
            return super(hr_holidays_status, self).name_get(cr, uid, ids, context=context)
        res = []
        for record in self.browse(cr, uid, ids, context=context):
            name = record.name
            name = name + ('  (%g/%g)' % (record.leaves_taken or 0.0, record.max_leaves or 0.0))
            res.append((record.id, name))
        return res