From: Justin Collins <justincollins@...>
Date: 2009-01-21T11:42:42+09:00
Subject: Re: cannot get attr_accessor to work

Tom Cloyd wrote:
> Justin Collins wrote:
>> Tom Cloyd wrote:
>>> I've been staring at this for a couple of hours, and I cannot crack 
>>> the nut. This SHOULD work, but I'm obviously screwing up. Just 
>>> cannot see where. I'm carefully following several examples, but...I 
>>> cannot get access to my instance variables.
>>>
>>> Here's a stripped down version of the code -
>>>
>>>
<snip>
>>>> (rdb:1) p run_log.log
>>>> NoMethodError Exception: undefined method `log' for nil:NilClass
>>>> (rdb:1)
>>> I would truly appreciate someone's pointing out the problem here.
>>>
>>> Thanks!
>>>
>>> Tom
>>>
>>
>>
>> Take a look at ManageLog#open. The last expression is a call to puts, 
>> which returns nil. You are setting the variable "run_log" to the 
>> result of the call to open in the debugger, but that result is nil. 
>> Then you try to call "log" on nil, thus the error.
>>
>> -Justin
>>
>>
> Well, nuts. That's crystal clear. Man, it's tough being a Ruby 
> amateur, when it 's not great fun, which it hasn't been for a couple 
> of hours.
>
> Thanks Justin. Much appreciated.
>
> t.


Just remember that whenever you see

NoMethodError Exception: undefined method `..." for nil:NilClass

look at what variable you are calling the method on. Then figure out why 
it is nil.

-Justin