How to Append Data to JSON in Ruby/Rails

how to append data to json in ruby/rails?

item = Item.find(params[:id])
item["message"] = "it works"
render :json => item.to_json

How do I append/add data to an JSON file with Ruby

Of course, simply joining two JSON strings together don't work and would result in an invalid JSON. In your example, the hash you try to add would not end up in the array but behind.

The correct way is to read the existing JSON file and parse it into a RUBY data structure and add the new hash in Ruby to the array before writing everything back to JSON.

require 'json'

filename = '/root/Desktop/jsonDatabase.json'

hash = { "first_name" => "john", "last_name" => "doe" }

array = JSON.parse(File.read(filename)
array << hash

File.open(filename, 'w') do |f|
  f.write(JSON.pretty_generate(array))
end

Appending the data in JSON file using Ruby

Uri Agassi's code is perfect, but I thought to explain what went wrong in the OP code.

The Hash[] expects an array of key, value pairs (either as separate arguments or an array of arrays):

Hash[:a, 1, :b, 2]        # => {:a=>1, :b=>2}
Hash[[[:a,1], [:b,2]]]    # => {:a=>1, :b=>2}

But the original JSON contained Array of Hashes which gets parsed into corresponding Ruby objects as in the simplified case:

[{:a => 1}, {:b => 2}]

When you use the Ruby splat operator * on the above array:

Hash[ *[{:a => 1}, {:b => 2}] ]

You efectively provide separate hashes as a key-value pair to the Hash constructor:

Hash[ {:a => 1}, {:b => 2} ]  # => {{:a=>1} => {:b=>2}}

So, essentially, you got what you asked for: you turned a array of hashes into a hash of hashes and then you added that to a blank array and topped up with another hash.

Correct solution

Just to make the original code work with minimal changes (but still take a look at Uri's solution):

tempHash = {"Group_Name" => @GroupName, "Group_Logo_Code" => @GroupLogoCode }

json = File.read('public/group.json')
secondJsonArray = JSON.parse(json)

secondJsonArray << tempHash

File.open("public/group.json","w") do |f|
  f.puts JSON.pretty_generate(secondJsonArray)
end

Ruby - Append data to existing JSON

You can use Array#push like this:

test = {
  :provisioningState=>"Succeeded",
  :resourceGuid=>"test",    
  :securityRules=>[
    {:name=>"SSH", :id=>"SSH", :etag=>"18",:type=>"Microsoft/securityRules", :properties=>{}}
  ]
}
new_rule = {
  :name => 'rule_2',
  :properties => {
    :protocol          => 'TCP',
    :sourceAddressPrefix => '*',
    :destinationAddressPrefix => '*',
    :access => 'Allow',
    :destinationPortRange => '22',
    :sourcePortRange => '*',
    :priority => '301',
    :direction => 'Inbound',
  }
}

test[:securityRules].push(new_rule)
test
# {
#   :provisioningState=>"Succeeded",
#   :resourceGuid=>"test",
#   :securityRules=> [
#     {:name=>"SSH", :id=>"SSH", :etag=>"18", :type=>"Microsoft/securityRules", :properties=>{}},
#     {:name=>"rule_2",:properties=>{:protocol=>"TCP",:sourceAddressPrefix=>"*",:destinationAddressPrefix=>"*",:access=>"Allow",:destinationPortRange=>"22",:sourcePortRange=>"*",:priori# ty=>"301",:direction=>"Inbound"}}
#   ]
# }

Add values to Ruby JSON Object

You could try this

json = { "data" => [
         {"name" => "A", "available" => "1"},
         {"name" => "B", "available" => "0"}
       ]}
json["data"].push({"name" => "C", "available" => "1"})

Appending to Json Array in ruby on rails

This should work for you:

render json: User.all.to_json(include: :tags)

or alternatively (just tag names):

render json: User.all.to_json(methods: :tag_list)

Append new values to an existing JSON array in ruby

In @scenario you have Array object, so if you wanna to add new hash inside this Array, just use Array#<< method like this.

Because the Array is object, you can add data inside this object.

new_scenario = {
  "ScenarioNumber" => 2,
  "ScenarioName" => "SC2",
  "ScenarioDescription" => "Desc",
  "ScExecutionStatus" => "Execution Complete",
  "ScenarioStatus" => "In-Complete",
  "ScenarioSeverity" => false,
  "TestCase" => [
    {
      "TestCaseNumber" => 1,
      "TestCaseName" => "Some Name ",
      "TcExecutionStatus" => "Execution Error",
      "TcStatus" => "NA",
      "TcSeverity" => "NA"
    }
  ]
}

@scenario << new_scenario

@template_file now include new_scenario

Append data from different model in json object

You may need to play with rails relationship here.

General speaking, your Question hasMany Like, and Like belongsTo Question. Same goes to Answer, Answer hasMany Like, and Like belongsTo Answer.

Since Like can belongsTo more than one model, you can try using Polymorphism Association.

http://guides.rubyonrails.org/association_basics.html#polymorphic-associations

How to add item to json object ruby on rails?

You can write a custom method in your model and call it in index action, which returns all the costs with the username like below:

def self.list_costs
  cost_list = []
  costs = Cost.all
  costs.each do |cost|
    cost_info = cost.attributes
    cost_info[:user_name] = cost.user.name
    cost_list << cost_info
  end
  cost_list
end  

class CostsController < ApplicationController
  def index
    render json: {costs: Cost.cost_list }
  end
end

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