change the name of nested keys received as parameter

问题

Hi in rails the nested parameters are passed with attributes appended to the key's and then its is passed to permit

If I receive normal hash and want to append attribute to each nested key before permit is called

How to do that ?

"project":{  
  "project_name":"test",
  "tentative_start_date":"2018-12-12",
  "tentative_end_date":"2019-12-12",
"project_roles":[  
     {  
        "role_id":1,
        "project_role_skills":[  
           {  
              "skill":{  
                 "skill_type":"C++",
                 "id":2
              }
           }
        ],
        "project_role_users":[  

        ],
        "role_end_date":"2018-12-12",
        "role_start_date":"2018-12-12"
     }
  ]

} }

This is the request I received and I want to append attribute to project_roles,project_role_skill and so on so that rails accept that

Please anyone help

回答1:

Have you tried this? Rails 4 - Strong Parameters - Nested Objects If it doesn't work for you, can you please specify what is your form currently and what is your current method using permit?

回答2:

TL;DR:

def params_with_deep_appended_nested_attributes(_params)
  modified_params = _params.clone

  _params.each do |k, v|
    if v.is_a?(Array)
      modified_params["#{k}_attributes"] = []

      v.each_with_index do |vv, index|
        if vv.is_a?(ActionController::Parameters)
          modified_params["#{k}_attributes"][index] = params_with_deep_appended_nested_attributes(vv)
        end
      end

      modified_params.delete(k)

    elsif v.is_a?(ActionController::Parameters)
      modified_params["#{k}_attributes"] = params_with_deep_appended_nested_attributes(v)
      modified_params.delete(k)
    end
  end

  modified_params
end

Usage Example:

# rails console
example_json_hash_request = {
  "project": {
    "project_name":"test",
    "tentative_start_date":"2018-12-12",
    "tentative_end_date":"2019-12-12",
    "project_roles": [
       {  
          "role_id":1,
          "project_role_skills":[  
             {  
                "skill":{  
                   "skill_type":"C++",
                   "id":2
                }
             }
          ],
          "project_role_users":[  

          ],
          "role_end_date":"2018-12-12",
          "role_start_date":"2018-12-12"
       }
    ]
  }
}

# simulate `params` value in the controller
params = ActionController::Parameters.new(example_json_hash_request)

modified_params = params_with_deep_appended_nested_attributes(params)

pp modified_params.permit!.to_hash
# {"project_attributes"=>
#   {"project_name"=>"test",
#    "tentative_start_date"=>"2018-12-12",
#    "tentative_end_date"=>"2019-12-12",
#    "project_roles_attributes"=>
#     [{"role_id"=>1,
#       "role_end_date"=>"2018-12-12",
#       "role_start_date"=>"2018-12-12",
#       "project_role_skills_attributes"=>
#        [{"skill_attributes"=>{"skill_type"=>"C++", "id"=>2}}],
#       "project_role_users_attributes"=>[]}]}}

Solution:

# app/controllers/application_controller.rb
class ApplicationController < ActionController::Base
  # ...
  # I added `= params` to default to the `params` value here in the controller
  def params_with_deep_appended_nested_attributes(_params = params)
    modified_params = _params.clone

    _params.each do |k, v|
      if v.is_a?(Array)
        modified_params["#{k}_attributes"] = []

        v.each_with_index do |vv, index|
          if vv.is_a?(ActionController::Parameters)
            modified_params["#{k}_attributes"][index] = params_with_deep_appended_nested_attributes(vv)
          end
        end

        modified_params.delete(k)

      elsif v.is_a?(ActionController::Parameters)
        modified_params["#{k}_attributes"] = params_with_deep_appended_nested_attributes(v)
        modified_params.delete(k)
      end
    end

    modified_params
  end
  # ...
end

# app/controllers/projects_controller.rb
class ProjectsController < ApplicationController
  def create
    @project = Project.new(project_params)

    if @project.save
      # ...
    else
      # ...
    end
  end

  def project_params
    params_with_deep_appended_nested_attributes.require(:project_attributes).permit(
      :project_name, :tentative_start_date, :tentative_end_date,
      project_roles_attributes: [
        :role_id, :role_end_date, :role_start_date,
        project_role_skills_attributes: [
          skill_attributes: [
            :skill_type, :id
          ]
        ],
        project_role_users_attributes: []
      ]
    )
  end
end

Don't forget to define the "nested attributes" in the models:

# app/models/project.rb
class Project < ApplicationRecord
  has_many :project_roles
  accepts_nested_attributes_for :project_roles
end

# app/models/project_role.rb
class ProjectRole < ApplicationRecord
  belongs_to :project
  has_many :project_role_skills
  has_many :project_role_users
  accepts_nested_attributes_for :project_role_skills
  accepts_nested_attributes_for :project_role_users
end

# app/models/project_role_skill.rb
class ProjectRoleSkill < ApplicationRecord
  belongs_to :project_role
  belongs_to :skill
  accepts_nested_attributes_for :skill
end

TODOs:

• add cahing of the params_with_deep_appended_nested_attributes return value, to avoid running the code each time params_with_deep_appended_nested_attributes is going to be called.

This question interests me. I might find use to this code of mine in the future.

来源：https://stackoverflow.com/questions/53722061/change-the-name-of-nested-keys-received-as-parameter