Find record in table and save id to another table in Rails

Question

I'm developing an app in which users can have a personal food diary.

It's pretty simple: a user can search for a nutrient on a Nutrients table (let's say milk) - currently through a pretty simple search form - and then should be able to save the amount he consumed of this nutrient (together with the nutrient_id) on a second table, which is called Diaries (that holds the nutrient_id as foreign key and an integer field called "amount").

My search works. I can also create new records in Diaries but I have to type in the nutrient_id manually.

My question is now how I can make this easily work? Ideally a user finds a nutrient clicks on it and will be redirected to a page that shows this nutrient together with a field for "amount" and a save button to save both information (nutrient_id and amount) on the Diaries table.

At the end of the day I think the user will be directed to the new action of my diary controller - the question is how my app sets the nutrient_id for this action for the nutrient the user selected before?

Sorry if this is a too simple question but I just started coding few weeks ago.

Thanks a lot for help!

My code looks like as follows:

nutrient.rb

class Nutrient < ActiveRecord::Base
  has_many :diaries

  def self.search(search)
    where("name LIKE ?", "%#{search}%") 
  end

end

diary.rb

class Diary < ActiveRecord::Base
  belongs_to :nutrient
end

nutrients_controller.rb

class NutrientsController < ApplicationController
  before_action :set_nutrient, only: [:show, :edit, :update, :destroy]

  # GET /nutrients
  # GET /nutrients.json
  def index
    @nutrients = Nutrient.all
  end

  def search
    if params[:search]
      @nutrients = Nutrient.search(params[:search]).order("created_at DESC")
      if @nutrients.present?
        @nutrients
      else
        flash[:notice] = "Nutrient not found in database"
      end
    end
  end

  # GET /nutrients/1
  # GET /nutrients/1.json
  def show
  end

  # GET /nutrients/new
  def new
    @nutrient = Nutrient.new
  end

  # GET /nutrients/1/edit
  def edit
  end

  # POST /nutrients
  # POST /nutrients.json
  def create
    @nutrient = Nutrient.new(nutrient_params)

    respond_to do |format|
      if @nutrient.save
        format.html { redirect_to @nutrient, notice: 'Nutrient was successfully created.' }
        format.json { render :show, status: :created, location: @nutrient }
      else
        format.html { render :new }
        format.json { render json: @nutrient.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /nutrients/1
  # PATCH/PUT /nutrients/1.json
  def update
    respond_to do |format|
      if @nutrient.update(nutrient_params)
        format.html { redirect_to @nutrient, notice: 'Nutrient was successfully updated.' }
        format.json { render :show, status: :ok, location: @nutrient }
      else
        format.html { render :edit }
        format.json { render json: @nutrient.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /nutrients/1
  # DELETE /nutrients/1.json
  def destroy
    @nutrient.destroy
    respond_to do |format|
      format.html { redirect_to nutrients_url, notice: 'Nutrient was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_nutrient
      @nutrient = Nutrient.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def nutrient_params
      params.require(:nutrient).permit(:name)
    end
end

diaries_controller.rb

class DiariesController < ApplicationController
  before_action :set_diary, only: [:show, :edit, :update, :destroy]

  # GET /diaries
  # GET /diaries.json
  def index
    @diaries = Diary.all
  end

  # GET /diaries/1
  # GET /diaries/1.json
  def show
  end

  # GET /diaries/new
  def new
    @diary = Diary.new
  end

  # GET /diaries/1/edit
  def edit
  end

  # POST /diaries
  # POST /diaries.json
  def create
    @diary = Diary.new(diary_params)

    respond_to do |format|
      if @diary.save
        format.html { redirect_to @diary, notice: 'Diary was successfully created.' }
        format.json { render :show, status: :created, location: @diary }
      else
        format.html { render :new }
        format.json { render json: @diary.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /diaries/1
  # PATCH/PUT /diaries/1.json
  def update
    respond_to do |format|
      if @diary.update(diary_params)
        format.html { redirect_to @diary, notice: 'Diary was successfully updated.' }
        format.json { render :show, status: :ok, location: @diary }
      else
        format.html { render :edit }
        format.json { render json: @diary.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /diaries/1
  # DELETE /diaries/1.json
  def destroy
    @diary.destroy
    respond_to do |format|
      format.html { redirect_to diaries_url, notice: 'Diary was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_diary
      @diary = Diary.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def diary_params
      params.require(:diary).permit(:nutrient_id, :amount)
    end
end

routes.rb

Rails.application.routes.draw do

  resources :diaries
  resources :nutrients do
    collection do
      get :search
    end
  end

_form.html.erb (for a new diary record)

<%= form_for(@diary) do |f| %>
  <% if @diary.errors.any? %>
    
      <%= pluralize(@diary.errors.count, "error") %> prohibited this diary from being saved:

      
      <% @diary.errors.full_messages.each do |message| %>
        <%= message %>
      <% end %>
      
    
  <% end %>

  
    <%= f.label :nutrient_id %>

    <%= f.number_field :nutrient_id %>
  
  
    <%= f.label :amount %>

    <%= f.number_field :amount %>
  
  
    <%= f.submit %>
  
<% end %>

oreoluwa · Accepted Answer

There are several ways to resolve this, one the quickest and most likely the best approach to me would be to nest the diaries under nutrients, since diaries belongs_to :nutrients

  resources :nutrients do
   resources :diaries
    collection do
      get :search
    end
  end

This way your all your diaries path method would accept a @nutrient argument and your route would be like: /nutrients/4/diaries/1

So in your diaries_controller, you could have:

class DiariesController < ApplicationController
   before_action :set_nutrient

   def new
    @diary = @nutrient.diaries.new
   end

   def create
    @diary = @nutrient.diaries.new(diary_params) # you can safely remove the nutrient_id from the strong params
    ... remaining logic here
   end
...
  private
   def set_nutrient
    @nutrient ||= Nutrient.find(params[:nutrient_id])
   end

   # You cans skip/ignore this method, if you don't want to be too strict
   def set_diary
    @diary ||= @nutrient.diaries.find(params[:id])
   end
end

Then in your view, you could then have:

<%= form_for([@nutrient, @diary]) do |f| %>
  <% if @diary.errors.any? %>
    
      <%= pluralize(@diary.errors.count, "error") %> prohibited this diary from being saved:

      
      <% @diary.errors.full_messages.each do |message| %>
        <%= message %>
      <% end %>
      
    
  <% end %>
  
    <%= f.label :amount %>

    <%= f.number_field :amount %>
  
  
    <%= f.submit %>
  
<% end %>

As I mentioned, there are still other ways of doing this, as you could also use hidden_fields however, this seem to be the cleanest way to me. If you don't always want your diaries routes to be nested, you could expect: [the list of actions that should not be nested, eg show], both on your before_action and your routes' resources :diaries. Hope I'm able to help or let me know other confusions you may encounter.

Find record in table and save id to another table in Rails

Answers (1)

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