try method under ActiveModel

[Rodrigo Rosenfeld Rosas]

Is there any reason why 'try' method behaves differently in ActiveModel?

I mean:

'string'.try :inexistent_method

yields an error...

Thanks in advance,

Rodrigo.

[Jeremy Kemper]

When you use Active Model standalone, you need to cherry-pick the
Active Support core extensions you wish to use:
require 'active_support/core_ext/object/try'

Or, to use them all:
require 'active_support/all'

jeremy

[Rodrigo Rosenfeld Rosas]

Jeremy Kemper escreveu:

Hi Jeremy, thank you for your reply.

Actually I'll avoid using try since I am writing a patch to ActiveModel
and it seems that ActiveModel should not depend on ActiveSupport, right?

I'm writing this pattern, instead: "foo = bar.inexistent_method if
bar.responds_to? :inexistent_method"

I'm a bit confuse about how to add a :full_message option to validations
without breaking backward compatibilities... Subclassing String doesn't
seem to be easy.

I'm inclined to do something like 'string'.extend SomeHelperClass and
:symbol.extend SomeHelperClass...

Have a good new year!

Best regards,

Rodrigo.

[Mateo Murphy]

On 31-Dec-09, at 2:05 PM, Rodrigo Rosenfeld Rosas wrote:
>>
> Hi Jeremy, thank you for your reply.
>
> Actually I'll avoid using try since I am writing a patch to
> ActiveModel
> and it seems that ActiveModel should not depend on ActiveSupport,
> right?
>
> I'm writing this pattern, instead: "foo = bar.inexistent_method if
> bar.responds_to? :inexistent_method"
>
> I'm a bit confuse about how to add a :full_message option to
> validations
> without breaking backward compatibilities... Subclassing String
> doesn't
> seem to be easy.
>
> I'm inclined to do something like 'string'.extend SomeHelperClass and
> :symbol.extend SomeHelperClass...

I'm not sure why you'd need to subclass string to add a full_message
option to validations? Could you explain how you were planning on
doing this?

[Jeremy Kemper]

On Thu, Dec 31, 2009 at 11:05 AM, Rodrigo Rosenfeld Rosas

<rr.r...@gmail.com> wrote:
> Jeremy Kemper escreveu:
>> On Thu, Dec 31, 2009 at 6:45 AM, Rodrigo Rosenfeld Rosas
>> <rr.r...@gmail.com> wrote:
>>
>>> Is there any reason why 'try' method behaves differently in ActiveModel?
>>>
>>> I mean:
>>>
>>> 'string'.try :inexistent_method
>>>
>>> yields an error...
>>>
>>> Thanks in advance,
>>>
>>
>> When you use Active Model standalone, you need to cherry-pick the
>> Active Support core extensions you wish to use:
>>   require 'active_support/core_ext/object/try'
>>
>> Or, to use them all:
>>   require 'active_support/all'
>>
>> jeremy
> Hi Jeremy, thank you for your reply.
>
> Actually I'll avoid using try since I am writing a patch to ActiveModel
> and it seems that ActiveModel should not depend on ActiveSupport, right?

Active Model does depend on Active Support, but it cherry-picks just
what it needs rather than including the whole enchilada. So you're
free to use the try extension.

jeremy

[Rodrigo Rosenfeld Rosas]

Hi Jeremy and Mateo, thank you for your feedback.

Mateo, I did not answer you before because I wanted to finish my attempt
and show it instead of talk about it.

Follows a patch in attachment (still missing tests and documentation) to
illustrate my idea.

If you think that could be accepted, I will add the tests, documentation
and will probably require the 'try' from active_support for better
readability.

What do you think?

Anyway, I want to wish all rails-core list members a happy new year!

Best regards,

Rodrigo.

[Rodrigo Rosenfeld Rosas]

Mateo Murphy escreveu:

Mateo, I was thinking in extending String because I didn't want to break
backwards compatibility, like changing Errors#add* method signatures and
I would like to preserve all the options on the attributes array.

I ended up giving up on this approach and only included a "full_message"
state on the validation.

I also has learned a bit more about Ruby... What would you expect from
the following snippet?

class NewString < String
def initialize(options={})
end
def to_s
options[:message]
end
end

puts NewString.new(:message => 'Hi')

I expected it would be 'Hi', but it is actually nil. :)

Thank you for your interest,

Rodrigo.

[Allen Madsen]

Rodrigo,

You should be doing something like:

class NewString < String
 def initialize(options={})

  @options = options
 end
 def to_s
   @options[:message]
 end
end

That will give you the desired result.

Allen Madsen
http://www.allenmadsen.com

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[Rodrigo Rosenfeld Rosas]

Allen Madsen escreveu:

> Rodrigo,
>
> You should be doing something like:
> class NewString < String
> def initialize(options={})
> @options = options
> end
> def to_s
> @options[:message]
> end
> end
>
> That will give you the desired result.

Sorry, that was exactly what I did (I have not copied and pasted).
Actually it was more like this:

class NewString < String
attr_reader :options

def initialize(options={})
@options = options
end
def to_s

options[:message]
end
end

Did you try your example?

It didn't work here...

> <mailto:rubyonra...@googlegroups.com>.

> To unsubscribe from this group, send email to
> rubyonrails-co...@googlegroups.com

> <mailto:rubyonrails-core%2Bunsu...@googlegroups.com>.

[Mateo Murphy]

On 31-Dec-09, at 4:44 PM, Rodrigo Rosenfeld Rosas wrote:
>>
> Sorry, that was exactly what I did (I have not copied and pasted).
> Actually it was more like this:
>
> class NewString < String
> attr_reader :options
> def initialize(options={})
> @options = options
> end
> def to_s
> options[:message]
> end
> end
>
> Did you try your example?
>
> It didn't work here...

print (which is called by puts) only calls to_s on objects that are
not strings. You might get this to work by implementing a different
method, but I'm not sure subclassing is the right way to go about this
in the first place...

[Rodrigo Rosenfeld Rosas]

Mateo Murphy escreveu:

Yes, I've read the documentation too after my tryout didn't work as I
expected...

What I didn't find was an instruction about how to subclass a String....

Did someone already tried this out?

Best regards,

Rodrigo.