Rails hash to array to hash how to?

Question

In my controller I have:

def index
    @title = 'asdsadas'
    @kategoris = Tag.where("name like ?", "%#{params[:q]}%")
    @kate = @kategoris.map(&:attributes).map{|d| d.map{|d| d.map{|d| d.dup.force_encoding("UTF-8") if d.respond_to?(:force_encoding) } } }
    respond_to do |format|
    format.html
    format.json { render :json => @kate }
    end
end

The problem is it has become an array:

[[["cached_slug","vinna-biljetter"],["created_at",null],["h1","inn biljetter - Delta i tävl

It should be a hash:

[{"cached_slug":"vinna-biljetter","created_at":"2011-04-28T10:33:05Z","h1":"inn biljetter -

Try turning the array into a hash then pass the hash into json. format.json { render :json => Hash[@kate] } I am not 100% sure if that would work but try it out. — ericraio
– ericraio, Commented Feb 24, 2012 at 0:07

Zsolt Botykai · Accepted Answer · 2012-02-25 17:30:23Z

3

Try this:

@kate = []
@kategoris.each do |kat|
  h = {}
  kat.attributes.each{|k,v| h[k] = v.respond_to?(:force_encoding) ? v.dup.force_encoding("UTF-8") : v }
  @kate << h
end

OR

 @kate = @kategoris.map{|k| k.attributes.inject({}){|h,(k,v)| h[k] = v.respond_to?(:force_encoding) ? v.dup.force_encoding("UTF-8") : v;h}}

@kate is now an array of hashes.

edited Feb 25, 2012 at 17:30

Zsolt Botykai

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answered Feb 23, 2012 at 23:53

Veraticus

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3 Comments

Rails beginner Over a year ago

I get this error in view: undefined method `attributes' for #<ActiveRecord::Relation:0x745cd40>

Veraticus Over a year ago

My bad, I didn't realize there were multiple @kategoris. Try the editted code.

Rails beginner Over a year ago

It removes the attributes, created_at and ID which is a problem.

Harish Shetty · Accepted Answer · 2012-02-25 19:00:41Z

1

Try this:

@kate = @kategoris.map |k|
 Hash[
   k.attributes.select{|k, v| v.respond_to?(:force_encoding)}.
     map{|k, v| [k, v.force_encoding("UTF-8")]}
 ]
end

PS:

The solution above selects only the values that support force_encoding. If you want to include other values:

@kate = @kategoris.map |k|
 Hash[
   k.attributes.map{|k, v| 
     [k, (v.respond_to?(:force_encoding) ? v.force_encoding("UTF-8") : v)]
   }
 ]
end

edited Feb 25, 2012 at 19:00

answered Feb 24, 2012 at 1:03

Harish Shetty

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2 Comments

Rails beginner Over a year ago

I get a syntax error with the first and last code: tags_controller.rb:6: syntax error, unexpected '|' @ kate = @ kategoris.map begin |k|

Rails beginner Over a year ago

I used .map{ |k| insted and } instead of end

pguardiario · Accepted Answer · 2012-02-24 00:07:58Z

0

There's always the Hash[*] trick:

Hash[*[['foo',1],['bar',2]].flatten]
=> {"foo"=>1, "bar"=>2}

answered Feb 24, 2012 at 0:07

pguardiario

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2 Comments

Rails beginner Over a year ago

Tried it, returned only 1 hash.

ericraio Over a year ago

Hash[[['foo',1],['bar',2]]] #=> {"foo"=>1, "bar"=>2} you can actually do this and not have to flatten.

YasirAzgar · Accepted Answer · 2018-02-15 10:01:47Z

0

This may not completely answer the question, still If you just want to convert a Hash to Array, just call to_a on the hash.

h = { "c" => 300, "a" => 100, "d" => 400, "c" => 300  }
h.to_a   #=> [["c", 300], ["a", 100], ["d", 400]]

Reference: https://ruby-doc.org/core-2.5.0/Hash.html#method-i-to_a

answered Feb 15, 2018 at 10:01

YasirAzgar

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