how to get each value from json in ruby sinatra? - ruby

Question

I need to extract each key-value of json and that value should save in database. but i am getting trouble in getting value of each key in json.
JSON
{
"topo": [
{
"dpid": "00:00:00:00:00:00:00:03",
"ports": [
3,
1
]
}
],
"app": "vm_migration"
}
code
post '/save_summary', :provides => :json do
begin
params = JSON.parse(request.env["rack.input"].read)
return params["topo"][0]["dpid"]
#above code return correct value
return params["topo"][0]["ports"] #this is not working
rescue Exception => e
return e.message
end
end
i don't know what's wrong with ports statement, please help me to figure out small issue.

Answer 1

What you are returning – params["topo"][0]["ports"] – is an array of two elements, which is one of the things you can return from a Sinatra route:
An Array with two elements: [status (Fixnum), response body (responds to #each)]
So you are trying to return a response with status 3 and body 1. The response body needs to be an object that responds to each, and 1 doesn’t. If you check your logs or console you will probably see an error undefined method `each' for 1:Fixnum. Assuming you just want to see the array in the browser, simply convert it to a string:
return params["topo"][0]["ports"].to_s
The first example works because params["topo"][0]["dpid"] is a string, and you can return strings from routes.