[RUBY] Make an instagram clone app ②

Introduction

As the title suggests, we will create a simplified Instagram app. I will write the article in the following steps, so I hope you will read it step by step.

① App creation-Implementation of login function ② Implementation of photo posting function ← Imakoko ③ [Implementation of user page] (https://qiita.com/maca12vel/items/c716702b02f977303011) ④ [Implementation of follow function] (https://qiita.com/maca12vel/items/2760d33f3683fac91de5) ⑤ Implementation of post deletion function

Introduction of Active Storage

What is Active Storage ... A function for uploading files If you use this, you can easily create an image posting function etc. with a form.

• Hereafter, in the application directory

Terminal

rails active_storage:install

Next, create a photo model. Since photo is associated with user, ```user: belongs_to Create a text type column by setting caption: text``

Terminal

rails g model photo user:belongs_to caption:text

And

Terminal

rails db:migrate

Finally, create the controller.

Terminal

rails g controller photos

The preparation is complete.

Create a link to the photo posting page

First, set the routing.

routes.rb

Rails.application.routes.draw do
  root 'homes#index'

  devise_for :users

  resources :photos #← here
end

Next, edit the home screen.

erb:app/views/homes/index.html.erb

<h3>home</h3>

<div>
  <%= link_to 'logout', destroy_user_session_path, method: :delete %>
</div>

<div>
  <%= link_to 'Photo posting', new_photo_path %>
</div>

Check new_photo_path with Prefix of ** rails routes **

Create new.html.erb in the photos model and write as follows for confirmation.

erb:app/views/photos/new.html.erb

<h3>Photo posting</h3>

If you can move from the home screen to the photo posting page as shown below, you are successful.

Controller settings

I will describe it in the controller created by rails g controller photos.

photos_controller.rb

class PhotosController < ApplicationController
  before_action :authenticate_user!

  def new
    @photo = current_user.photos.new
  end

  def create
    @photo = current_user.photos.new(photo_params)

    if @photo.save
      redirect_to :root
    else
      render :new
    end
  end

  private

  def photo_params
    params.require(:photo).permit(:caption, :image)
  end
end

With before_action: authenticate_user!, It is set so that only logged-in users can post.

Create action with argument (photo_params) (photo_params) is defined under private.

Also with the create action If the save is successful, the home screen will be displayed. ** If it fails, it is set to return (stay) to the new posting screen **.

Edit view of new post screen

Before that, check the association between the ʻuser model and the "photos model`. Since user and photos have a one-to-many relationship, edit as follows.

user.rb

class User < ApplicationRecord
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable, :trackable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :validatable

  has_many :photos #← here
end

photo.rb

class Photo < ApplicationRecord
  belongs_to :user #← Described at rails g model photo

  has_one_attached :image #← here
end

has_one_attached: Column name is used to attach one image to the model. When linking multiple images, use has_many_attached: column name.

Since this is one image, it is called has_one_attached. By the way, the way of writing when displaying an image is different between one and many.

has_one_attached

<%= image_tag(@photo.image) %>

has_many_attached

<% images.count.times do |i| %>
  <%= image_tag(@photo.image[i]) %>
<% end %>

has_many_attached: column name The image is stored as an array, so it looks like the above.

Although the introduction has become long, I will edit the view of the new post screen.

erb:app/views/photos/new.html.erb

<h3>Photo posting</h3>

<%= form_with model: @photo, local: true do |f| %>
  <div>
    <%= f.file_field :image %>
  </div>
  <div>
    <%= f.text_area :caption %>
  </div>
  <%= f.submit %>
<% end %>

Display the posted image on the home screen.

• This is for confirmation only, so we will correct it later.

erb:app/views/homes/index.html.erb

<h3>home</h3>

<div>
  <%= link_to 'logout', destroy_user_session_path, method: :delete %>
</div>

<div>
  <%= link_to 'Photo posting', new_photo_path %>
</div>

<% current_user.photos.each do |photo| %>
  <div>
    <p><%= photo.caption %></p>
    <%= image_tag photo.image %>
  </div>

I try to display all posts in each statement.

From the new post page, click Select File, Enter caption, Create Photo, If you can post as follows, I think that it is in shape for the time being.

that's all. Thank you for your hard work.

Next → ③ [Implementation of user page] (https://qiita.com/maca12vel/items/c716702b02f977303011)