Is there a way to make this one liner better looking?
@var = params[:key1][:key2] unless params.blank? || params[:key1].blank?
views:
86answers:
7
+1
A:
Yes, there is.
@var = params && params[:key1] && params[:key1][:key2]
Bragboy
2010-09-16 09:06:27
In your case `=` will be done in any way, but in questioner's — only when right from `unless` is equal to `false`
Nakilon
2010-09-16 09:09:50
This works really well for testing for `.nil?` values but not for `.blank?`
Shadwell
2010-09-16 09:10:35
good refactoring, although i think the original one is more 'readable' or understandable with one look. but nonetheless, good refactor
corroded
2010-09-16 09:10:46
@Shadwell: checking if params[:key1] is blank is not neccessary, nil check is enough - we want to avoid exception here, on blank hash asking for :key2 gives nil which is ok
gertas
2010-09-16 09:35:17
Anyway it works wrong. If some params lack, @var will become false, but do we need it?
Nakilon
2010-09-16 10:18:13
@Nakilon : If some params lack, @var will not become false. It will be nil..
Bragboy
2010-09-16 10:52:40
Anyway it deletes previous value.
Nakilon
2010-09-16 11:27:47
The OP's code assigns the value of params[:key1][:key2] to @var, doesn't this code lose that?
Jeff Paquette
2010-09-16 13:03:52
Wow, thanks for all the replies :-) As gertas point out that params is always present in a controller action (which is indeed where I'm working), and that nil check is enough, my original code can be reduced to @var = params[:key1][:key2] unless params[:key1].nil?
Jeppe Liisberg
2010-09-16 14:54:35
+1
A:
You can use this:
params.blank? || params[:key1].blank? || (@var = params[:key1][:key2])
But your way is more readable for me.
Nakilon
2010-09-16 09:13:50
A:
Just to let you know that you can also do this, but i'm not sure it is better looking :) (and you have to be in ror):
@var = params.try(:fetch, :key1, nil).try(:fetch, :key2, nil)
hellvinz
2010-09-16 09:14:53
A:
Chris McCauley
2010-09-16 09:28:41
A:
I assume that you are using it in controller (params allways present - not nil):
@var = (params[:key1] || {})[:key2]
gertas
2010-09-16 09:30:32
A:
This is a simple idea.
@var = params.fetch(:key1, {}).fetch(:key2, nil)
Using merge is interesting.
@var = {:key1=>{}}.merge(params)[:key1][:key2]
Shinya Miyazaki
2010-09-16 10:48:14
A:
Wow, thanks for all the replies!
I'm going to sum up the answers - as the answer seems more subtle than just another oneliner ;-)
As gertas point out that params is always present in a controller action (which is indeed where I'm working), and that nil check is enough, my original code can thus be reduced to:
@var = params[:key1][:key2] unless params[:key1].nil?
This is quite readable but not as short as other suggestions, like
params[:key1].nil? || (@var = params[:key1][:key2])
@var = params[:key1] && params[:key1][:key2]
or even
@var = (params[:key1] || {})[:key2]
I wondered how to use rubys try() method on hashes, and hellvinz gave the answer (rewritten to match my new/realized need):
@var = params[:key1].try(:fetch, :key2, nil)
Finally, Shinya Miyazaki came up with some interesting variations using fetch and merge:
@var = params.fetch(:key1, {}).fetch(:key2, nil)
@var = {:key1=>{}}.merge(params)[:key1][:key2]
I ended up going with "my own", to honor the principle of "Clarity over Brevity" as pointed out by Chris McCauley
Thanks again everyone! :-)
Jeppe Liisberg
2010-09-16 15:15:50