I'm playing around with nested hashes and I'm trying to figure out how to fetch multiple keys when my hash is a nested one:
imahash = { :id => { :name => "Alma", :email => "alma#mail.com" },
:stats => { :gender => "Female" },
:location => { :city => "Freeport", :state => "Maine" }
}
I know how to retrieve the nested value, and typing in the hash name will dump all the keys and values. But what I want to do is to fetch specific keys, such as :name and :gender only. Or :name and :city only.
Is this possible? Because from what I've found, it seems that you can only retrieve hash values for one key at a time or for all the keys at once.
My desired output would be something like:
=> { :id => { :name => "Alma" }, :location => { :city => "Freeport" } }
I presume you want to grab the values out in a tuple? You can make an array that contains whatever collection of values you want.
Try the following for name and city:
[imahash[:id][:name], imahash[:location][:city]]
=> ["Alma", "Freeport"]
Not exactly sure what you're asking here, but it seems like you're wanting to create a new hash from the bigger one.
To fetch specific keys like :name and :gender only
name_and_gender_hash = {
:name => imahash[:id][:name],
:gender => imahash[:stats][:gender]
}
would result in
{:name => "Alma", :gender => "female"}
Related
I have been trying for ages. I am trying to round an array with hashes.
[
{
:email => "user_01#yorlook.com",
:amount => 129.22500000000002
},
{
:email => "user_02#yorlook.com",
:amount => 112.67500000000001
}
]
I need a method to make it look like this:
[
{
:email => "user_01#yorlook.com",
:amount => 129.23
},
{
:email => "user_02#yorlook.com",
:amount => 112.68
}
]
Thanks for your help in advance!
Assuming arr always contains Hash with key amount which is a Float (as in example).
arr.each { |hash|
hash[:amount] = hash[:amount].round(2)
}
#=> [{:email=>"user_01#yorlook.com", :amount=>129.23}, {:email=>"user_02#yorlook.com", :amount=>112.68}]
I'm trying to create different kind of structure from the array I currently have in my code.
I've got an array of objects (active directory objects) so lets say i got a from db :
a = [o1,o2,o3,o4,o5]
My object has property source_id and name which are the relevant properties.
I want to create structure like this (I want hash) from the data I have in my array :
objects = Hash.new { |hash, key| hash[key] = [] }
And this would be one example of how to put the data inside new structure:
a.each do |ob|
objects[ob.source_id] << {
:new => '',
:name => {:unformated => ob.name, :formatted => ob.format(:name)}
}
end
I'm trying to replicate the same structure and it's not working out in my case :
a.group_by(&:source_id).map do |k,v|
{
k=> {
{
:new => '',
:name => {:unformated => v.name, :formatted => ob.format(:name)}
}
}
}
end.reduce(:merge)
This is the error I get :
! #<NoMethodError: undefined method `name' for #<Array:0xae542b4>>
With group_by your values in the a.group_by(&:source_id).map are going to be arrays of elements sharing the same source_id and not individual elements.
The following code may do what you wish:
a.group_by(&:source_id).map do |k,v|
{
k => v.map do |e|
{
:new => '',
:name => {:unformated => e.name, :formatted => e.format(:name)}
}
end
}
end.reduce(:merge)
Heres a one liner to do the same
new_hash = a.each_with_object({}) { |o, hash| hash[o.source_id] = {:new => '', :unformatted => o.name, :formatted => o.format(:name)} }
This does require ruby 1.9.3 though
I'm trying to retrieve data in a nested form from the following two tables (in SQLite)
DB = Sequel.sqlite('database.sqlite')
DB.create_table? :artists do
primary_key :id
String :name
end
DB.create_table? :albums do
primary_key :id
String :title
foreign_key :artist_id,
:artists,
:key => :id
end
artists = DB[:artists]
albums = DB[:albums]
id1 = artists.insert(:name => 'Mike')
id2 = artists.insert(:name => 'John')
albums.insert(:title => 'Only You', :artist_id => id1 )
albums.insert(:title => 'Only Us', :artist_id => id1 )
albums.insert(:title => 'Only Me', :artist_id => id2 )
The output I'm trying to get -
[
{
:id => 1,
:name => 'Mike'
:albums => [
{
:id => 1,
:title => 'Only You'
},
{
:id => 2,
:title => 'Only Us'
}
]
},
{
:id => 2,
:name => 'John'
:albums => [
{
:id => 3,
:title => 'Only Me'
}
]
}
]
I've tried 'eager' loading -
class Artist < Sequel::Model(:artists)
one_to_many :db[:albums], :key => :artist_id
end
class Album < Sequel::Model(:albums)
many_to_one :artist, :key => :artist_id
end
Artist.eager(:albums).all{ |a| p a }
But that didn't work.
Can anyone point me in the right direction?
Artist.eager(:albums).all does eagerly load the albums, but {|a| p a} is not going to show the albums (as Sequel::Model#inspect only shows values for the current model, not any associated objects). Use {|a| p [a, a.albums]} to see that the albums are already loaded.
If you want to produce the hash you described:
Artist.eager(:albums).all.map do |a|
a.values.merge(:albums=>a.albums.map{|al| al.values})
end
You can add a method to Artist to output it the way you want it
class Artist < Sequel::Model(:artists)
one_to_many :albums, :key => :artist_id
def my_hash
to_hash.merge!(
{
:albums => albums.map{|a|
a.to_hash.reject!{ |k,v|
k==:artist_id
}
}
}
)
end
end
class Album < Sequel::Model(:albums)
many_to_one :artist, :key => :artist_id
end
records = Artist.all.map{ |a| a.my_hash }
p records
Instead of using reject! it would be cleaner to add a my_hash method the Album to return a hash without the :artist_id, but you get the idea. This outputs:
[
{
:albums=>[
{
:title=>"Only You",
:id=>1
},
{
:title=>"Only Us",
:id=>2
}
],
:name=>"Mike",
:id=>1
},
{
:albums=>[
{
:title=>"Only Me",
:id=>3
}
],
:name=>"John",
:id=>2
}
]
Normally I have:
cookies[:location] = { :value => { :city => 'foo', :country => 'bar' } }
However, sometimes :country is not set. When I do:
cookies[:location][:country].present?
to check if country has been set, it returns an error:
[:country] is not a symbol
How would I check to see if a country is set in cookie[:location] if I cannot do it this way?
You cookies hash is nested differently than you are expecting: :value is nested under :location, :city and :country are nested under :value. Here is some irb output to get you started:
[~]$ irb
>> cookies={}
=> {}
>> cookies[:location] = { :value => { :city => 'foo', :country => 'bar' } }
=> {:value=>{:city=>"foo", :country=>"bar"}}
>> cookies[:location][:value][:country]
=> "bar"
>> cookies.to_s
=> "{:location=>{:value=>{:city=>\"foo\", :country=>\"bar\"}}}"
If you nest the hash like below, you will get your expected behavior:
>> cookies[:location] = { :city => 'foo', :country => 'bar' }
=> {:city=>"foo", :country=>"bar"}
>> cookies[:location][:country]
=> "bar"
I'm looking at using Ruby savon for SOAP. For purely masochistic reasons I have to deal with SOAP elements having attributes.
So, no problem, there is an example on the savon docs site which highlights this ability:
{ :person => "Eve", :attributes! => { :person => { :id => 666 } } }.to_soap_xml
"<person id=\"666\">Eve</person>"
My problem is how do I set attributes on child elements, for example, say I add an address child element to person:
{ :person => {:address => ""}, :attributes! => { :person => { :id => 666 } } }.to_soap_xml
Now I want to add an id attribute to the address element:
It's no go if I nest address in the attributes hash:
{ :person => {:address => ""}, :attributes! => { :person => { :id => 666, :address => {:id => 44 }} }}.to_soap_xml
So my question is, how can I get this?
<person id=666><address id=44></address></person>
I ran across the issue of the previous answer no longer working. Eventually I found https://github.com/savonrb/savon/issues/518 which lead me to the correct syntax to add attributes now.
So the previous example would now be done as
{
:person => {
:#id => 666,
:address => {
:#id => 44
}
}
}
Which would generate the following xml
<person id="666">
<address id="44"/>
</person>
You were close - just needed to put the :attributes! key in the same hash that contains the value.
{
:person => {
:address => "",
:attributes! => { :address => { :id => 44 } }
},
:attributes! => { :person => { :id => 666 } }
}.to_soap_xml
# => "<person id=\"666\"><address id=\"44\"></address></person>"