Troubleshooting "can't modify frozen object" in tzinfo_timez

Rails
1

Hi. Off and on I get a “can’t modify frozen object” when working with
the tzinfo_timezone plugin. I’ve added some debugging in the code to
try and track down what goes wrong:

def tzinfo
RAILS_DEFAULT_LOGGER.debug(“TZINFO STATE ‘#{@tzinfo}’ class
#{@tzinfo.class} frozen? #{@tzinfo.frozen?}”)
return @tzinfo if @tzinfo
RAILS_DEFAULT_LOGGER.debug(“TZINFO ASSIGN TO #{MAPPING[name]}”)
begin
@tzinfo = MAPPING[name]
rescue TypeError => type_error
RAILS_DEFAULT_LOGGER.debug(“TZINFO TYPE ERROR #{type_error}”)
raise type_error
end
RAILS_DEFAULT_LOGGER.debug(“TZINFO ASSIGNED TO #{@tzinfo}”)
if String === @tzinfo
@tzinfo = TZInfo::Timezone.get(@tzinfo)
MAPPING[name] = @tzinfo
end
@tzinfo
end

When the error occurs, the following makes it to the log:

TZINFO STATE ‘’ class NilClass frozen? false
TZINFO ASSIGN TO Europe/Amsterdam
TZINFO TYPE ERROR can’t modify frozen object

Which means, that @tzinfo is nil, and yet, the line

@tzinfo = MAPPING[name]

Causes a TypeError. MAPPING is a hash. I’m mildly confused. Anyone
able to shed some light on what might be the issue or how to dig
further into the problem?

ruby 1.8.4 (2005-12-24) [x86_64-linux]

Thanks.

Morten

2

On 1/30/07, Morten [email protected] wrote:

begin
@tzinfo

Morten

Morten,

Not sure what’s causing this exactly. Why are you trying to load the
tzinfo from a MAPPING hash?

Check out the timezone code in mephisto for a really slick way to
handle timezones. It helped me quite a bit.

Hope this helps.

–
Zack C.
http://depixelate.com

3

Zack,

Morten,

Not sure what’s causing this exactly. Why are you trying to load the
tzinfo from a MAPPING hash?

The code I’m trying to debug is actually tzinfo_timezone.rb, so the
error occurs within the plugin. I just use it like:

In my user model:

composed_of :tz, :class_name => ‘TimeZone’, :mapping => %w(time_zone
name)

In my view:

<%= format_date(@current_user.tz.utc_to_local(entry.created_at)) %>

The hash is part of tzinfo_timezone.rb’s way of associating time zones
with locations.

Thanks for the tip on Mephisto, I’ll look into their way og handling
time zones.

Br,

Morten

4

On 1/31/07, Morten [email protected] wrote:

error occurs within the plugin. I just use it like:
The hash is part of tzinfo_timezone.rb’s way of associating time zones
with locations.

Thanks for the tip on Mephisto, I’ll look into their way og handling
time zones.

This line should be:

composed_of :tz, :class_name => ‘TzinfoTimezone’, :mapping =>
%w(time_zone name)

I think the mappings are slightly different between the two which
would explain the intermittent crashes.

–
Zack C.
http://depixelate.com

5

Morten wrote:

Hi. Off and on I get a “can’t modify frozen object” when working with
the tzinfo_timezone plugin. I’ve added some debugging in the code to
try and track down what goes wrong:

…

Thanks.

Morten

Has anybody figured out why this occurs and how to fix it? It’s odd
that the error only occurs sporadically.

Thanks,
Andrew

6

The tzinfo_timezone plugin, in the init.rb script, actually replaces
Rails’ TimeZone class with TzinfoTimezone, so using either one of
those should work as the :class_name (I think?),

-tieg