rails custom key in params hash

Question

I have a model CommunityPartner with a has_and_belongs_to_many relationship with another model PartnerTag.

class CommunityPartner < ActiveRecord::Base
    VALID_EMAIL = /\A[\w+\-.]+@{1}[a-z\d\-.]+\.[a-z]+\z/i

    validates(:name, presence: true, uniqueness: true)
    validates(:email, presence: true, confirmation: true, 
                      format: { with: VALID_EMAIL })
    validates(:contact_method, presence: true)
    validates(:email_confirmation, presence: true)
    validates(:address, presence: true)
    validates(:phone_number, presence: true)
    validates(:description, presence: true)

    has_many(:projects, dependent: :destroy)
    has_and_belongs_to_many(:partner_tags)

    has_secure_password

    def create_tag_list(tag_list)
        tag_list.each do |tag|
            t = PartnerTag.new(name: tag.name)
            self.partner_tags << t
        end
    end
end

class PartnerTag < ActiveRecord::Base
    validates(:name, presence: true)

    has_and_belongs_to_many(:community_partners)
end

I've successfully created a form for a new partner, except for one thing: the partner's tags. I've created a method that creates the list of tags from an array. That array is made of a method that takes a string and separates it by spaces (it's in the controller below). How can I customize the params hash so that I can include a custom parameter from the form that is specifically for the string of tags? Alternatively, is there a better way to do this?

Here's the controller code:

class CommunityPartnersController < ApplicationController
    def index
        @all_partners = CommunityPartner.all
    end

    def new
        @new_partner = CommunityPartner.new
    end

    def create
        # create tag list from string passed in params[:community_partner][:pa    rtner_tags]
        # append each tag in list to partner instance
        @new_partner = CommunityPartner.new(allowed_community_partner_params)
        @new_partner.create_tag_list(parse_tags(params[:tags]))
        if(@new_partner.save)
            redirect_to(@new_partner)
        else
            render(:new)
        end
    end

    def edit
    end

    def show
        @partner = CommunityPartner.find(params[:id])
    end

    def update
    end

    def destroy
    end

    def parse_tags(tag_list)
        tag_list.split(/ /)
    end

    private

        def allowed_community_partner_params
            params.require(:community_partner).permit(:name, :email, 
                                   :display_email, :email_confirmation, :contact_method,
                                   :password, :password_confirmation, :phone_number,
                                   :address, :description)
    end
end

Answer 1

Sounds like you just need an attr_accessor in your CommunityPartner model. i.e.

class CommunityPartner < ActiveRecord::Base
   attr_accessor :tag_list
end

You can then add that attribute to your form and access it from params as params[:community_partner][:tag_list]. This would also cleanup your create_tag_list method as you would not need to pass a parameter. Remember to add :tag_list to your list of permitted attributes in the controller.

Answer 2

You could use a combination of the gems acts_as_taggable_on and chosen-rails to reduce user error (not including the space when separating tags.

Acts As Taggable On

Simple and maintained gem for adding tags to your Rails model.

• http://railscasts.com/episodes/382-tagging
• https://github.com/mbleigh/acts-as-taggable-on

Chosen Rails

Converts your textbox into a token based text box similar to how SO's tagging works.

https://github.com/tsechingho/chosen-rails