How can I iterate a JSON object in a rails controller?

Question

I'm passing the following data set to my controller in JSON format:

[
    {id: 0, exercises: [15, 18]},
    {id: 1, exercises: [33, 35]} 
]

This is received in my controller where I have to following code to display it temporarily:

arr = params["_json"]
binding.pry

This gives me the following output in the pry console:

[3] pry(#<ProgramsController>)> arr
=> [<ActionController::Parameters {"id"=>0, "exercises"=>[16, 7, 18]} permitted: false>,
<ActionController::Parameters {"id"=>1, "exercises"=>[14, 15]} permitted: false>]

I can then iterate this by going through arr[0] and arr[1], but how do I get the exercises that lie within these indexes?

So I can do something like this.

arr.each do |x|
  prog = Program.create(x ...)
  x.each do |exercise|
    prog.exercises.create(exercise_id: exercise.id)
  end
end

Hope someone can help me out handling this data. Thanks!

Answer 1

尝试使用 JSON.parse :)

arr = JSON.parse params["_json"]

Answer 2

The solution was quite simply: arr[0]["exercises"]

No parsing needed, thanks tho :)

Answer 3

To iterate over JSON in Rails. Try the following:

<ul>
arr.each do |a|
   <li><%= a[id] %></li>
   <li><%= a[exercises] %></li>
end
</ul>

OR

you can also try

@result = JSON.parse(HTTParty.get(your_url).body)
@result["arr"].each do |key, value|
  puts key
  puts value
end