ORM JSON request handling for dataset insert

Question

I am trying to view the JSON request which is sent from POSTMAN through a POST request to add a security group info to a table, and my request looks like one below

POST /securitygroup HTTP/1.1
Host: localhost:9292
Content-Type: application/json
Cache-Control: no-cache
Postman-Token: c4bef1db-d544-c923-3b0b-e7004e2dd093

{
  "securitygroup":{
    "secgrp_id": 124,
    "secgrp_nm": "SECURITY ADMIN",
    "secgrp_profile_nme": "ADMIN"
  }
}

Roda code looks like below

# cat config.ru
require "roda"
require "sequel"
require "oci8"
require "json"

DB = Sequel.oracle(host: 'xyz.dev.com', port: '1525', database: 'devbox1', user: 'abc', password: 'pass')

class App < Roda
  plugin :json, classes: [Array, Hash, Sequel::Model, Sequel::Dataset]

  route do |r|
    # secgroup = DB[:security_groups]
    # secgroup.insert(r.params["securitygroup"])
    # secgroup 
    # above insert threw the following error
    # OCIError: ORA-00947: not enough values,
    # because SQL generated as below
    # INSERT INTO "SECURITYGROUPS" VALUES (NULL)
    # so I am trying to access the request object 'r', I feel that I am doing 
    # something which is not correct 

    {"response": r.params.["securitygroup"]["secgrp_id"]}
    # throws undefined method `[]' for nil:NilClass
  end 
end

Can you please take a look at the request and point me, where am I going wrong, Request format not correct or is there a different way to handle the request on the ruby code.

I need help to parse the request that comes in as JSON similar to code presented in https://twin.github.io/introduction-to-roda/

  r.post "albums" do
    album = Album.create(r.params["album"])
    r.redirect album_path(album) # /albums/1
  end

Answer 1

You need just a little tweak: Add to the App the plugin :json_parser.

class App < Roda
  # use this plugin to convert response to json
  plugin :json

  # use this plugin to convert request from json
  plugin :json_parser

  ...

end

See in the Roda documentation "Plugins that Ship with Roda" in the group "others" there is the json_parser plugin.