Rails app: I need to build a json object from params inside a loop

Question

I need to build a json object inside a loop using params.

My params look like this...

params[:answers]
returns => {"1"=>"answer1", "2"=>"answer2"}

The keys in this json object are the id's of the survey question.

So I planed to loop through the keys to build the json object like this...

def build_answersheet_json(params[:answers], params[:survey_id])
  params[:answers].keys.each do |question_id|
    current_question = question_id
    current_answer = params[:answers][question_id]
  end
end

Since im using "t.json" in my migration to save json to postgres, I wanted to use the extracted question_id and answer to build a json object that looks something like this...

{
  survey_id: '1',
  answers: {
    question: [{
      question_id: 1,
      answer: 'answer1'
    }, {
      question_id: 2,
      answer: 'answer2'
      }]
  }
}

Ive been trying to do this using a method that looks somthing like this...

build_answersheet_json(params[:answers], params[:survey_id])

Ive tried JSON.parse() and Ive tried to just logically work through it but I cant seem to figure this out.

Any help is appreciated.

luiscrjr · Accepted Answer · 2017-01-14 11:23:29Z

1

Maybe you can try something like that:

/* fake params (to test) */
params = {
    survey_id: '1',
    answers: {
        "1"=>"answer1", 
        "2"=>"answer2", 
        "3"=>"answer3", 
        "4"=>"answer4"
    }
}

def build_answersheet_json(answers, survey_id)
  {
    survey_id: survey_id,
    answers: answers.map { |k,v| { question_id: k.to_i, answer: v } }
  }
end


survey = build_answersheet_json(params[:answers], params[:survey_id])

puts survey.class 
#Hash

puts survey.to_json
# formated JSON string:
# {
#   "survey_id":"1",
#   "answers":[
#       {"question_id":1,"answer":"answer1"},
#       {"question_id":2,"answer":"answer2"},
#       {"question_id":3,"answer":"answer3"},
#       {"question_id":4,"answer":"answer4"}
#   ]
# }

In order to save to a t.json postgress column type, just pass the Hash survey object, like that:

YourModel.create(survey: survey)

Source: http://edgeguides.rubyonrails.org/active_record_postgresql.html

edited Jan 14, 2017 at 11:23

answered Jan 14, 2017 at 10:26

luiscrjr

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2 Comments

Verty00 Over a year ago

This looks uber promising. Thanks for the quick reply. I have to hit the sack right now but I will run this through in the morning.

Verty00 Over a year ago

Thanks! This worked perfectly. Thanks for citing the article too!

Tallboy · Accepted Answer · 2017-01-14 19:31:19Z

1

Try

{
  survey: ¯\_༼◉ل͟◉༽_/¯,
}

answered Jan 14, 2017 at 19:31

Tallboy

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Comments

oklas · Accepted Answer · 2017-01-14 10:22:36Z

0

Json may not be parsed if json have construction like this:

survey = {
}

Json may not contain = and assignment

Check real variables values with puts varname.inspect near at code lines where you meet unexpected behaviour.

answered Jan 14, 2017 at 10:22

oklas

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1 Comment

Verty00 Over a year ago

Im sorry, the survey = {} should not be there. I just want the final object to look like what is after the " = " I will edit the question.

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