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How can an object have its "self" and "name" instance variables nil after being instantiated?

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Julien Delplanque

How can an object have its "self" and "name" instance variables nil after being instantiated?

Hi,

I have an object that override KMCategory and that is initialized and
added to "KmRepository default" using #postLoadDoIt: message in
BaselineOf after the package is loaded in an image.

But once it is loaded I have huge problems with keyboards entries, they
do not work any more, I get an exception each time I press a key.

If I inspect the Singleton class variable of my category object I can
see it contains an instance of my object that have its "self" variable
nil and its "name" variable nil. Others variables look fine. How is it
possible?

I can remove my custom KMCategory by copy/paste code from sublime text
to Pharo and left click/do it and then everything is fine with my
keyboard: no more exception and it behave correctly.

Thanks in advance,

Julien

jtuchel

Re: How can an object have its "self" and "name" instance variables nil after being instantiated?

I don't have an exact answer for you, but I think neither self nor name are good names for inst vars.

> Am 25.08.2015 um 15:57 schrieb Julien Delplanque <[hidden email]>:
>
> Hi,
>
> I have an object that override KMCategory and that is initialized and added to "KmRepository default" using #postLoadDoIt: message in BaselineOf after the package is loaded in an image.
>
> But once it is loaded I have huge problems with keyboards entries, they do not work any more, I get an exception each time I press a key.
>
> If I inspect the Singleton class variable of my category object I can see it contains an instance of my object that have its "self" variable nil and its "name" variable nil. Others variables look fine. How is it possible?
>
> I can remove my custom KMCategory by copy/paste code from sublime text to Pharo and left click/do it and then everything is fine with my keyboard: no more exception and it behave correctly.
>
> Thanks in advance,
>
> Julien
>
>

Julien Delplanque

Re: How can an object have its "self" and "name" instance variables nil after being instantiated?

I didn't do anything like using these names as inst vars. You can
reproduce what I am talking about:

KMCategory new inspect.

On 25/08/15 17:25, Joachim Tuchel wrote:

> I don't have an exact answer for you, but I think neither self nor name are good names for inst vars.
>
>
>
>> Am 25.08.2015 um 15:57 schrieb Julien Delplanque <[hidden email]>:
>>
>> Hi,
>>
>> I have an object that override KMCategory and that is initialized and added to "KmRepository default" using #postLoadDoIt: message in BaselineOf after the package is loaded in an image.
>>
>> But once it is loaded I have huge problems with keyboards entries, they do not work any more, I get an exception each time I press a key.
>>
>> If I inspect the Singleton class variable of my category object I can see it contains an instance of my object that have its "self" variable nil and its "name" variable nil. Others variables look fine. How is it possible?
>>
>> I can remove my custom KMCategory by copy/paste code from sublime text to Pharo and left click/do it and then everything is fine with my keyboard: no more exception and it behave correctly.
>>
>> Thanks in advance,
>>
>> Julien
>>
>>

Sven Van Caekenberghe-2

Re: How can an object have its "self" and "name" instance variables nil after being instantiated?

Well, name is an instance variable that is simply nil.

Self is printed as nil because this object has its own #gtDisplayOn: method that prints just its name.

You could try 'Basic Inspect' as well.

> On 25 Aug 2015, at 17:30, Julien Delplanque <[hidden email]> wrote:
>
> I didn't do anything like using these names as inst vars. You can reproduce what I am talking about:
>
> KMCategory new inspect.
>
> On 25/08/15 17:25, Joachim Tuchel wrote:
>> I don't have an exact answer for you, but I think neither self nor name are good names for inst vars.
>>
>>
>>
>>> Am 25.08.2015 um 15:57 schrieb Julien Delplanque <[hidden email]>:
>>>
>>> Hi,
>>>
>>> I have an object that override KMCategory and that is initialized and added to "KmRepository default" using #postLoadDoIt: message in BaselineOf after the package is loaded in an image.
>>>
>>> But once it is loaded I have huge problems with keyboards entries, they do not work any more, I get an exception each time I press a key.
>>>
>>> If I inspect the Singleton class variable of my category object I can see it contains an instance of my object that have its "self" variable nil and its "name" variable nil. Others variables look fine. How is it possible?
>>>
>>> I can remove my custom KMCategory by copy/paste code from sublime text to Pharo and left click/do it and then everything is fine with my keyboard: no more exception and it behave correctly.
>>>
>>> Thanks in advance,
>>>
>>> Julien
>>>
>>>
>
>

Mariano Martinez Peck

Re: How can an object have its "self" and "name" instance variables nil after being instantiated?

The problem is that KMCategory reimplements #name, which is not a good idea. And that is the method used by the inspector. Since the implementation of #name answers the instVar that's why it's nil. just remove KMCategory >> name and do the inspect again and you will see the different.

On Tue, Aug 25, 2015 at 12:39 PM, Sven Van Caekenberghe <[hidden email]> wrote:

Well, name is an instance variable that is simply nil.

Self is printed as nil because this object has its own #gtDisplayOn: method that prints just its name.

You could try 'Basic Inspect' as well.

> On 25 Aug 2015, at 17:30, Julien Delplanque <[hidden email]> wrote:
>
> I didn't do anything like using these names as inst vars. You can reproduce what I am talking about:
>
> KMCategory new inspect.
>
> On 25/08/15 17:25, Joachim Tuchel wrote:
>> I don't have an exact answer for you, but I think neither self nor name are good names for inst vars.
>>
>>
>>
>>> Am 25.08.2015 um 15:57 schrieb Julien Delplanque <[hidden email]>:
>>>
>>> Hi,
>>>
>>> I have an object that override KMCategory and that is initialized and added to "KmRepository default" using #postLoadDoIt: message in BaselineOf after the package is loaded in an image.
>>>
>>> But once it is loaded I have huge problems with keyboards entries, they do not work any more, I get an exception each time I press a key.
>>>
>>> If I inspect the Singleton class variable of my category object I can see it contains an instance of my object that have its "self" variable nil and its "name" variable nil. Others variables look fine. How is it possible?
>>>
>>> I can remove my custom KMCategory by copy/paste code from sublime text to Pharo and left click/do it and then everything is fine with my keyboard: no more exception and it behave correctly.
>>>
>>> Thanks in advance,
>>>
>>> Julien
>>>
>>>
>
>

Mariano
http://marianopeck.wordpress.com

Mariano Martinez Peck

Re: How can an object have its "self" and "name" instance variables nil after being instantiated?

Well...Sven explained #gtDisplayOn: and he nailed it.

On Tue, Aug 25, 2015 at 12:54 PM, Mariano Martinez Peck <[hidden email]> wrote:

The problem is that KMCategory reimplements #name, which is not a good idea. And that is the method used by the inspector. Since the implementation of #name answers the instVar that's why it's nil. just remove KMCategory >> name and do the inspect again and you will see the different.

On Tue, Aug 25, 2015 at 12:39 PM, Sven Van Caekenberghe <[hidden email]> wrote:
Well, name is an instance variable that is simply nil.

Self is printed as nil because this object has its own #gtDisplayOn: method that prints just its name.

You could try 'Basic Inspect' as well.

> On 25 Aug 2015, at 17:30, Julien Delplanque <[hidden email]> wrote:
>
> I didn't do anything like using these names as inst vars. You can reproduce what I am talking about:
>
> KMCategory new inspect.
>
> On 25/08/15 17:25, Joachim Tuchel wrote:
>> I don't have an exact answer for you, but I think neither self nor name are good names for inst vars.
>>
>>
>>
>>> Am 25.08.2015 um 15:57 schrieb Julien Delplanque <[hidden email]>:
>>>
>>> Hi,
>>>
>>> I have an object that override KMCategory and that is initialized and added to "KmRepository default" using #postLoadDoIt: message in BaselineOf after the package is loaded in an image.
>>>
>>> But once it is loaded I have huge problems with keyboards entries, they do not work any more, I get an exception each time I press a key.
>>>
>>> If I inspect the Singleton class variable of my category object I can see it contains an instance of my object that have its "self" variable nil and its "name" variable nil. Others variables look fine. How is it possible?
>>>
>>> I can remove my custom KMCategory by copy/paste code from sublime text to Pharo and left click/do it and then everything is fine with my keyboard: no more exception and it behave correctly.
>>>
>>> Thanks in advance,
>>>
>>> Julien
>>>
>>>
>
>

--
Mariano
http://marianopeck.wordpress.com

Mariano
http://marianopeck.wordpress.com

Julien Delplanque

Re: How can an object have its "self" and "name" instance variables nil after being instantiated?

Ok, thanks for your answers.

I think this is involved in the problem I had but I solved it by
changing my approach anyway :).

On 25/08/15 17:55, Mariano Martinez Peck wrote:

> Well...Sven explained #gtDisplayOn: and he nailed it.
>
> On Tue, Aug 25, 2015 at 12:54 PM, Mariano Martinez Peck <
> [hidden email]> wrote:
>
>> The problem is that KMCategory reimplements #name, which is not a good
>> idea. And that is the method used by the inspector. Since the
>> implementation of #name answers the instVar that's why it's nil. just
>> remove KMCategory >> name and do the inspect again and you will see the
>> different.
>>
>>
>>
>> On Tue, Aug 25, 2015 at 12:39 PM, Sven Van Caekenberghe <[hidden email]>
>> wrote:
>>
>>> Well, name is an instance variable that is simply nil.
>>>
>>> Self is printed as nil because this object has its own #gtDisplayOn:
>>> method that prints just its name.
>>>
>>> You could try 'Basic Inspect' as well.
>>>
>>>> On 25 Aug 2015, at 17:30, Julien Delplanque <[hidden email]> wrote:
>>>>
>>>> I didn't do anything like using these names as inst vars. You can
>>> reproduce what I am talking about:
>>>> KMCategory new inspect.
>>>>
>>>> On 25/08/15 17:25, Joachim Tuchel wrote:
>>>>> I don't have an exact answer for you, but I think neither self nor
>>> name are good names for inst vars.
>>>>>
>>>>>
>>>>>> Am 25.08.2015 um 15:57 schrieb Julien Delplanque <[hidden email]>:
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> I have an object that override KMCategory and that is initialized and
>>> added to "KmRepository default" using #postLoadDoIt: message in BaselineOf
>>> after the package is loaded in an image.
>>>>>> But once it is loaded I have huge problems with keyboards entries,
>>> they do not work any more, I get an exception each time I press a key.
>>>>>> If I inspect the Singleton class variable of my category object I can
>>> see it contains an instance of my object that have its "self" variable nil
>>> and its "name" variable nil. Others variables look fine. How is it possible?
>>>>>> I can remove my custom KMCategory by copy/paste code from sublime
>>> text to Pharo and left click/do it and then everything is fine with my
>>> keyboard: no more exception and it behave correctly.
>>>>>> Thanks in advance,
>>>>>>
>>>>>> Julien
>>>>>>
>>>>>>
>>>>
>>>
>>>
>>
>> --
>> Mariano
>> http://marianopeck.wordpress.com
>>
>
>