Thought Stream Rails App Tutorial Part 1

The goal of this web app is for a user to be able to create an account and sign in. On the main page of the app there will be a "thought stream" input text area. When the user inputs text representing things on their mind, that entry is stored in the database and we will display a chronological list of entries on the main page. The color of the text of each word from the line of entries will depend upon its frequency in the database of past entries.

If you do not have Ruby on Rails set up, I suggest you utilize The Odin Project. You do not need any Rails experience to do this tutorial. This is meant as exposure to the concepts and flows of writing rails apps. Hopefully this series will spark questions and ideas that you can act upon. Please leave comments with any questions, suggestions, corrections etc. Learning web development is a team sport and you cannot learn it by sitting on the side lines so let's dive in!

For this app, I am using ruby version 3.0.0, and rails version 6.1.3. Terminal commands will be denoted with a $ sign.

In the terminal run the following. Start by created a new rails app called "thought_stream".

$ rails new thought_stream

Generate (g for short) a scaffold called entry and create a column in the entries database called thoughts which will be a string (you can also write thoughts:string but leaving off the data type defaults to string).

$ rails g scaffold entry thoughts
$ rails db:migrate

Set the root route in config/routes.rb to be the index page for entries. You can check which routes are available by running $ rails routes in the terminal.

Rails.application.routes.draw do
  resources :entries

  root 'entries#index'


I want the input form for new entries to be on the same page as the color coded and chronological display of the thought streams. Modify app/controllers/entries_controller.rb

class EntriesController < ApplicationController
  before_action :set_entry, only: %i[ show edit update destroy ]

  # GET /entries or /entries.json
  def index
    @entry =
    @entries = Entry.all

  # GET /entries/1 or /entries/1.json
  def show

  # GET /entries/new
  def new
    @entry =


In app/views/entries/index.html.erb render the entries _form partial so that the thought stream input box will appear on the same page as our root index.

<p id="notice"><%= notice %></p>

<%= render 'form', entry: @entry %>


Adding @entry = to the index method of the entries controller gives us access to @entry in entries/index.html.erb. This made it possible to render the new entry form on our main index page.

Resizing and User Experience

Run $ rails s in the command line and visit localhost:3000. You should see a text field at the top but it is small. Head to app/views/entries/_form.html.erb and give the text field a class name text-field__thoughts, set a placeholder for the text area. Set the text area to autofocus for a more fluid user experience on the app.

Now that we have a placeholder we can delete the default for label that rails gave us. Delete <%= form.label :thoughts %> from the entries _form.html.erb partial. In app/views/entries/_form.html.erb you should have:

  <div class="field">
    <%= form.text_field :thoughts, 
                       class: "text-field__thoughts", 
                       placeholder: "Write down what's on your mind separated by commas...",                        
                       rows: 3, 
                       autofocus: true %>

Rename app/assets/stylesheets/application.css to app/assets/stylesheets/application.scss

Set the width of the text area in app/assets/stylesheets/entries.scss

  width: 99%;

After we create a new entry, rails sends us to the show page by default. For a smoother user experience we would like to stay on the same page to see the new entry added and color coded in real time. Redirect to the entries_path instead of @entry in entries_controller.rb.


format.html { redirect_to @entry, notice: "Entry was successfully created." }


format.html { redirect_to entries_path, notice: "Entry was successfully created." }

In app/views/entries/edit.html.erb change:

<h1>Editing Entry</h1>

<%= render 'form', entry: @entry %>

<%= link_to 'Show', @entry %> |
<%= link_to 'Back', entries_path %>


<h1>Editing Entry</h1>

<%= render 'form', entry: @entry %>

<%= link_to 'Delete', @entry, method: :delete, data: { confirm: 'Are you sure?' } %>  |  
<%= link_to 'Back', entries_path %>

This consolidates the UD actions of CRUD (create, read, update, destroy) to the edit page for entries. I think this makes the main page look cleaner.

Speaking of which, clean up views/entries/index.html.erb to look like:

<p id="notice"><%= notice %></p>

<%= render 'form', entry: @entry %>


    <% @entries.each do |entry| %>
        <td><%= link_to "added " + time_ago_in_words(entry.created_at) +" ago", edit_entry_path(entry) %></td>
        <td><%= entry.thoughts %></td>
    <% end %>

We got rid of the table header and added a column to the left to show when the entry was created. Now the user can click on the entry time link to be able to edit or delete the entry. Later we will create a "delete all" button for this page.

Thanks for sticking with me all the way to the end of part one of building the Thought Stream App!

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