Merge lp:~openerp-dev/openobject-server/6.0-bug-747746-xrg into lp:openobject-server/6.0

[xrg]

[Vo Minh Thu (thu)]

I'm not sure such 'utility' function has its place in the code just to write tests, especially that it has no documentation, and no associated tests.

review: Disapprove

[Vo Minh Thu (thu)]

The code might prove useful in multiple places. Before merging and using it, we would need to make sure this is what we want. A few things to think about:

- is there anything already doing something similar, either in python or as concrete syntax (to not reinvent the wheel)?
- is it possible to directly write something like this in yaml
    date: today + 2 days
  or does it need a new !bang syntax or use of !python?
- have a solid semantic regarding date/datetime conversions
- things like
    in 2 days, 2 days ago, monday in 1 month, next monday,...
  ?

[Vo Minh Thu (thu)]

Anyway, this is not much important. This is mostly a end-user experience thing, we don't really care for the developers. And nothing has been decided for the user interface about this.

I will reject this proposal even if we might want to include it later for user experience reason.

[xrg (xrg)]

On Thursday 12 May 2011, you wrote:
> The code might prove useful in multiple places. Before merging and using
> it, we would need to make sure this is what we want. A few things to think
> about:
>
> - is there anything already doing something similar, either in python or as
> concrete syntax (to not reinvent the wheel)?
The only concrete function is in PHP. For python, there is a wrapper that
calls the PHP strtotime(), but I imagine that's not what we would ever use.

> - is it possible to directly write something like this in yaml
> date: today + 2 days
> or does it need a new !bang syntax or use of !python?
It is not possible, since the values of fields are passed as "scalar
expressions", which means the string is pushed as-is to the var. Thus, it is
cleaner and safer to use an explicit operator. I thought "!date" and
"!datetime" are easy to guess/use.

> - have a solid semantic regarding date/datetime conversions
> - things like
> in 2 days, 2 days ago, monday in 1 month, next monday,...
> ?
I have a stash for this enhancement. However, while trying to implement that,
I discovered that the English text (like ones you propose) is ambiguous in
several cases. I wanted a little more time + discussion with community, to
standardize that.
I'd be happy to show you these half-implemented extensions and have your
opinion on the ambiguity.

>Anyway, this is not much important. This is mostly a end-user experience
thing..

In some cases, it makes our life much easier. We have had a lot of yaml test
either failing or doing wrong computations because of hard-coded (or poor
relative) dates/times. Apart from that, if we could agree[1] on an
implementation (wrt. syntax of the expressions), we could extend their usage
in other fields. For example, we could allow them to appear in xml files, in
formulae (imagine the production scheduler to be able to be set "now +3days at
14:00") etc.

[1] I never claim this code is perfect, feel free to propose a better
solution.

Unmerged revisions

3389. By xrg on 2011-04-01

tools: 'date_eval' utility for relative dates in YAML

Every end of the month, we face the problem that some YAML tests fail
because of naive date calculations (without curry).
Provide a utility function that will parse dates/times like "now+2days".

=== added file 'bin/tools/date_eval.py'
--- bin/tools/date_eval.py	1970-01-01 00:00:00 +0000
+++ bin/tools/date_eval.py	2011-04-01 20:43:38 +0000
@@ -0,0 +1,86 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+import re
+import time
+import datetime
+from dateutil.relativedelta import relativedelta
+
+re_abstimes = { 'now': datetime.datetime.now,
+                'today': datetime.date.today,
+                'tomorrow': lambda: (datetime.date.today() + datetime.timedelta(1)),
+                'yesterday': lambda: (datetime.date.today() - datetime.timedelta(1)),
+                }
+
+rel_units = { 'yr' : 'Y',
+            'year': 'Y',
+            'years': 'Y',
+            'month': 'M',
+            'months': 'M',
+            'mo': 'M',
+            'd': 'D',
+            'day': 'D',
+            'days': 'D',
+            'h': 3600,
+            'hr': 3600,
+            'hour': 3600,
+            'hours': 3600,
+            'm': 60,
+            'min': 60,
+            'minute': 60,
+            'minutes': 60,
+            's': 1,
+            'sec' : 1,
+            'second': 1,
+            'seconds': 1,
+            }
+
+re_dateeval = re.compile(r"(?P<abs>" + '|'.join(re_abstimes) +")"
+        r"|(?:(?P<rel>(?:\+|-)[0-9]+)(?P<rel_unit>" + '|'.join(rel_units)+ "))"
+        r"|(?: ?\bon ?(?P<date>[0-9]{1,2}(?:/[0-9]{1,2}(?:/[0-9]{2,4})?)?))"
+        r"|(?: ?\bat ?(?P<time>[0-9]{1,2}(?::[0-9]{2}(?::[0-9]{2})?)?))"
+        r"| +", re.I)
+
+def date_eval(rstr):
+    cur_time = datetime.datetime.now()
+    for m in re_dateeval.finditer(rstr):
+        if m.group('abs'):
+            cur_time = re_abstimes[m.group('abs')]()
+            if not isinstance(cur_time, datetime.datetime):
+                cur_time = datetime.datetime.fromordinal(cur_time.toordinal())
+            
+        elif m.group('rel'):
+            mrel = int(m.group('rel')[1:])
+            if m.group('rel')[0] == '-':
+                mrel = 0 - mrel
+            mun = rel_units[m.group('rel_unit')]
+            if mun == 'Y':
+                drel = relativedelta(years=mrel)
+            elif mun == 'M':
+                drel = relativedelta(months=mrel)
+            elif mun == 'D':
+                drel = datetime.timedelta(days=mrel)
+            else:
+                drel = mrel * datetime.timedelta(seconds=mun)
+
+            cur_time = cur_time + drel
+        elif m.group('date'):
+            dli = map(int, m.group('date').split('/'))
+            if len(dli) == 2:
+                dli += [cur_time.year,]
+            elif len(dli) == 1:
+                dli += [cur_time.month, cur_time.year]
+            cur_time = datetime.datetime.combine(datetime.date(dli[2],dli[1],dli[0]), cur_time.time())
+        elif m.group('time'):
+            dli = map(int, m.group('time').split(':'))
+            if len(dli) == 2:
+                dli += [cur_time.second,]
+            elif len(dli) == 1:
+                dli += [cur_time.minute, cur_time.second]
+            cur_time = datetime.datetime.combine(cur_time.date(), datetime.time(dli[0],dli[1],dli[2]))
+        else:
+            pass
+
+    return cur_time
+
+#eof

=== modified file 'bin/tools/yaml_tag.py'
--- bin/tools/yaml_tag.py	2010-12-03 14:20:35 +0000
+++ bin/tools/yaml_tag.py	2011-04-01 20:43:38 +0000
@@ -1,5 +1,7 @@
 import yaml
 import logging
+from date_eval import date_eval
+from misc import DEFAULT_SERVER_DATE_FORMAT, DEFAULT_SERVER_DATETIME_FORMAT
 
 class YamlTag(object):
     """
@@ -90,7 +92,7 @@
         super(Eval, self).__init__()
     def __str__(self):
         return '!eval %s' % str(self.expression)
-    
+
 class Ref(YamlTag):
     def __init__(self, expr="False", *args, **kwargs):
         self.expr = expr
@@ -150,6 +152,16 @@
     expression = loader.construct_scalar(node)
     return Eval(expression)
     
+def date_constructor(loader, node):
+    expression = loader.construct_scalar(node)
+    # TODO return a datetime.date object, not string
+    return date_eval(expression).strftime(DEFAULT_SERVER_DATE_FORMAT)
+
+def datetime_constructor(loader, node):
+    expression = loader.construct_scalar(node)
+    # TODO return a datetime.datetime object
+    return date_eval(expression).strftime(DEFAULT_SERVER_DATETIME_FORMAT)
+
 def ref_constructor(loader, tag_suffix, node):
     if tag_suffix == "id":
         kwargs = {"id": loader.construct_scalar(node)}
@@ -177,6 +189,8 @@
     yaml.add_constructor(u"!delete", delete_constructor)
     yaml.add_constructor(u"!url", url_constructor)
     yaml.add_constructor(u"!eval", eval_constructor)
+    yaml.add_constructor(u"!date", date_constructor)
+    yaml.add_constructor(u"!datetime", datetime_constructor)
     yaml.add_multi_constructor(u"!ref", ref_constructor)
     yaml.add_constructor(u"!ir_set", ir_set_constructor)
 add_constructors()