Method conditional option pattern

Rails
1

When I have this pattern

   sign_me(@user, :event => :authentication, :subdomain =>

subdomain)

how can I write it to avoid sending the :subdomain option if
subdomain.nil?
( if possible …)

   sign_me(@user, :event => :authentication  #?, :subdomain =>

subdomain unless subdomain.nil? )

2

On Fri, Nov 9, 2012 at 3:27 PM, Erwin [email protected] wrote:

When I have this pattern

   sign_me(@user, :event => :authentication, :subdomain => subdomain)

how can I write it to avoid sending the :subdomain option if
subdomain.nil? ( if possible …)

   sign_me(@user, :event => :authentication  #?, :subdomain =>

subdomain unless subdomain.nil? )

I’m not sure if it’s possible to do it in a single line (as far as you
want
to have a tidy code)

opts = { event: :authentication }
opts[:subdomain] = subdomain if subdomain

sign_me @user, opts

–

3

thanks

Le vendredi 9 novembre 2012 08:27:59 UTC+1, Erwin a crit :

4

On 9 November 2012 07:27, Erwin [email protected] wrote:

When I have this pattern

   sign_me(@user, :event => :authentication, :subdomain => subdomain)

how can I write it to avoid sending the :subdomain option if subdomain.nil?
( if possible …)

   sign_me(@user, :event => :authentication  #?, :subdomain => subdomain

unless subdomain.nil? )

You could try
sign_me(@user, :event => :authentication, (:subdomain =>
subdomain unless subdomain.nil?) )
or
sign_me(@user, :event => :authentication, :subdomain =>
(subdomain unless subdomain.nil?) )

Colin

5

On 9 November 2012 09:37, Jim Ruther N. [email protected] wrote:

subdomain unless subdomain.nil?) )
from

/home/jim/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.2/lib/rails/commands/console.rb:47:in

`start’
from

/home/jim/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.2/lib/rails/commands/console.rb:8:in

`start’
from

/home/jim/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.2/lib/rails/commands.rb:41:in

<top (required)>' from script/rails:6:in require’
from script/rails:6:in `’

I am not surprised that did not work, my answer was not intended to
convey any suggestion that it would work, just something that would be
interesting to try.

or
sign_me(@user, :event => :authentication, :subdomain =>
(subdomain unless subdomain.nil?) )

and this still passes subdomain as a key if used in a hash but if used in a
routes helper, this will work :smiley:

Yes, it will pass the subdomain as nil, so it depends on the context
whether this is satisfactory.

Colin

6

I have a related question.
I was suggesting Erwin to use just:

sign_me(@user, :event => :authentication #?, :subdomain => subdomain)

because if subdomain is nil, sign_me should correctly handle it.
I mean, in an hypothetical sign_in method I’d write:

def sign_me(user, options)
if options[:subdomain]
# do_something
end
end

if subdomain is nil the method handles it correctly.
but with this code:

def sign_me(user, options)
if options.has_key? :subdomain
# do_something
end
end

this goes wrong (“options.has_key? :subdomain” is true)! So I’d say the
first implementation seems more correct, do you agree with me or I’
missing something important about checking hash parameters?

7

On 9 November 2012 13:44, Tommaso V. [email protected]
wrote:

# do_something

end
end

if subdomain is nil the method handles it correctly.

That is the way I would do it.

Colin

8

Thanks Colin

I finally decided to keep the :subdomain option and let the method
decide
about what to do with it ( seems to be the common pattern)

Le vendredi 9 novembre 2012 10:26:34 UTC+1, Colin L. a crit :

9

On Fri, Nov 9, 2012 at 5:25 PM, Colin L. [email protected]
wrote:

subdomain

unless subdomain.nil? )

You could try
sign_me(@user, :event => :authentication, (:subdomain =>
subdomain unless subdomain.nil?) )

I was surprised that you answered this Colin so I tried it out but I got
a
syntax error

app.root_path(foo: ‘me’, (bar: ‘blah’ if false))
SyntaxError: (irb):17: syntax error, unexpected tLABEL
app.root_path(foo: ‘me’, (bar: ‘blah’ if false))
^
(irb):17: syntax error, unexpected ‘)’, expecting tASSOC
from
/home/jim/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.2/lib/rails/commands/console.rb:47:in
start' from /home/jim/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.2/lib/rails/commands/console.rb:8:in start’
from
/home/jim/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.2/lib/rails/commands.rb:41:in
<top (required)>' from script/rails:6:in require’
from script/rails:6:in `’

or
sign_me(@user, :event => :authentication, :subdomain =>
(subdomain unless subdomain.nil?) )

and this still passes subdomain as a key if used in a hash but if used
in a
routes helper, this will work :smiley:

app.root_path(foo: ‘me’, bar: (‘blah’ if false))
=> “/?foo=me”

https://groups.google.com/d/msg/rubyonrails-talk/-/TOTAudTTAa8J.
For more options, visit https://groups.google.com/groups/opt_out.

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