Loop through array of hashes in rails

Question

I have the following array of hashes that I send to my controller:

comparisons = [{
  "startdate": "01/01/2016",
  "enddate": "01/02/2016"
}, {
  "startdate": "01/03/2016",
  "enddate": "01/04/2016"
}, {
  "startdate": "01/05/2016",
  "enddate": "01/06/2016"
}, {
  "startdate": "01/05/2016",
  "enddate": "01/06/2016"
}];

$.ajax({
  url: '/get_data',
  method: 'GET',
  dataType: 'JSON',
  data: {
    startdate: '01/01/2016',
    enddate: '01/01/2016',
    comparisons: comparisons
  },
  success: function (data) {
    console.log(data);
  }
});

And then in the controller I want to loop through these comparisons:

@comparisons = []
if !params[:comparisons].blank?
  params[:comparisons].each do |c|
    @comparisons.push({:startdate => c[:startdate], :enddate => c[:enddate], :data => get_data(c[:startdate], c[:enddate], 'week')})
  end
end

I get an error: > no implicit conversion of Symbol into Integer

And when debugging I'm finding that the c in my loop isn't structured the same as what I'm sending...

c: ["0", {"startdate"=>"01/01/2016", "enddate"=>"01/01/2016"}]

How can I fix this?

Answer 1

easiest fix would be to change how you refer to the c data... you can see that c is an array (explains the error, it's expecting array elements to be accessed by an integer) and you can see the second (last) element of the c array has the data you want.

@comparisons.push({:startdate => c.last[:startdate], 
                   :enddate => c.last[:enddate], 
                   :data => get_data(c.last[:startdate], c.last[:enddate], 'week')})