从Ruby on Rails中的嵌套参数中获取值

Question

I use jQuery DataTables plugin with Ruby on Rails, and I'm having problem with retrieving the value on the nested params.

When I tried to inspect using

puts params.inspect

I got the following in my console

Parameters: {"draw"=>"1", "columns"=>{"0"=>{"data"=>"0", "name"=>"", "searchable"=>"false", "orderable"=>"false", "search"=>{"value"=>"", "regex"=>"false"}}, "1"=>{"data"=>"1", "name"=>"", "searchable"=>"true", "orderable"=>"true", "search"=>{"value"=>"", "regex"=>"false"}}, "2"=>{"data"=>"2", "name"=>"", "searchable"=>"true", "orderable"=>"true", "search"=>{"value"=>"", "regex"=>"false"}}, "3"=>{"data"=>"3", "name"=>"", "searchable"=>"true", "orderable"=>"true", "search"=>{"value"=>"", "regex"=>"false"}}, "4"=>{"data"=>"4", "name"=>"", "searchable"=>"false", "orderable"=>"false", "search"=>{"value"=>"", "regex"=>"false"}}}, "order"=>{"0"=>{"column"=>"1", "dir"=>"asc"}}, "start"=>"0", "length"=>"10", "search"=>{"value"=>"", "regex"=>"false"}, "_"=>"1438662290344"}

I want to get the value from :order, I changed my code to be like following

puts params[:order].inspect

Then I got the following in my console

{"0"=>{"column"=>"1", "dir"=>"asc"}}

I wanna get the value of "dir"=>"asc", I tried the following codes but still no luck

puts params[:order][0][:dir].inspect
puts params["order"][0]["dir"].inspect

Any advice would be much appreciated, thanks.

Answer 1

You first need to format the params-hash in way that you can actually see the structure. Like this:

{
    "draw"=>"1", 
    "columns"=>{
         "0"=>{"data"=>"0", "name"=>"", "searchable"=>"false", "orderable"=>"false", "search"=>{"value"=>"", "regex"=>"false"}}, 
         "1"=>{"data"=>"1", "name"=>"", "searchable"=>"true", "orderable"=>"true", "search"=>{"value"=>"", "regex"=>"false"}}, 
         "2"=>{"data"=>"2", "name"=>"", "searchable"=>"true", "orderable"=>"true", "search"=>{"value"=>"", "regex"=>"false"}}, 
         "3"=>{"data"=>"3", "name"=>"", "searchable"=>"true", "orderable"=>"true", "search"=>{"value"=>"", "regex"=>"false"}}, 
         "4"=>{"data"=>"4", "name"=>"", "searchable"=>"false", "orderable"=>"false", "search"=>{"value"=>"", "regex"=>"false"}}
   }, 
   "order"=>{
       "0"=>{"column"=>"1", "dir"=>"asc"}}, 
       "start"=>"0", 
       "length"=>"10", 
       "search"=>{"value"=>"", "regex"=>"false"}, 
    "_"=>"1438662290344"}
}

Now it is quite clear: You have strings as keys, also for the numbers, and you should get the information you need by using:

params["order"]["0"]["dir"]