如何在序列化程序中迭代 hash 数组

Question

I have a grouped collection and I want to serialize it but it returns me with an error 'undefined method `read_attribute_for_serialization' for # '. This is my sample data without serializer:

{
    "message": "success",
    "data": {
        "reports": {
            "export": [
                {
                    "name": "Order",
                    "report_type": "export",
                    "parameters": "\"{order_date: '10-10-2019'}\"",

                },
                {
                    "name": "Order",
                    "report_type": "export",
                    "parameters": "\"{order_date: '10-10-2019'}\"",
                }],
            "import": [
                {
                    "name": "Order",
                    "report_type": "import",
                    "parameters": "\"{order_date: '10-10-2019'}\"",
                },
                {
                    "name": "Order",
                    "report_type": "import",
                    "parameters": "\"{order_date: '10-10-2019'}\"",
                }
            ],
            "details": [
                {
                    "name": "Order",
                    "report_type": "details",
                    "parameters": "\"{order_date: '10-10-2019'}\"",
                },
                {
                    "name": "Order",
                    "report_type": "details",
                    "parameters": "\"{order_date: '10-10-2019'}\"",
                }
            ]
        }
    }
}

This is my serializer:

class ReportSerializer < ActiveModel::Serializer
  attributes :id, :name, :report_type, :parameters

  def parameters
    JSON.parse(object.parameters)
  end
end

This is my controller code:

  def reports_list
    reports = Report.all.group_by(&:report_type)
    render_collection(reports, { name: 'reports' }, each_serializer: ReportSerializer)
  end

But return me with an error: undefined method `read_attribute_for_serialization' for #<Hash:0x0000562eebbddee8>

Please help. Thanks.

Answer 1

*.group_by() is an Enumerable method which returns Hash - I think render_collection expects to receive ActiveRecord::Relation - use *.group(:report_type) instead