My Sinatra web based application

After working on my Sinatra web based application, i worked on a few parts

there was the relational aspects of it ie. a song belongs to a user and a user has many songs

# song.rb
class Song < ActiveRecord::Base
 belongs_to :user
end
#user.rb
class User < ActiveRecord::Base 
     has_many :songs, dependent: :destroy   
     has_secure_password
     validates :username, :email, presence: true  
     validates :username, :email, uniqueness: true
end

there was the session implementation aspect which saves that user session when it is created

#users_controller.rb
class UsersController < ApplicationController
   get '/signup' do   
    erb :'users/signup' 
   end  
 
post '/signup' do    @user = User.new(params)
     if @user.save        
     session[:user_id] = @user.id      
     redirect '/songs'   
   else     
     redirect '/signup'    
   end  
end
   
get '/login' do 
   flash[:login] = "Have An Account?"
    erb :'users/login'
  end
   
post '/login' do
    #make sure email exists in db    
   @user = User.find_by(username:params[:username])
    #check if password is valid
    if @user && @user.authenticate(params[:password])
        session[:user_id] = @user.id
          flash[:login] = "Login Successful!"
        redirect "/songs"
    else
flash[:login] = "Please Enter A Valid Username/Password, Or Simply Create An Account"       
 redirect "/login"    
  end  
end

the by-crypt end which allows a user to have a secure password and have a password digest that not even the developer can view

has_secure_password

the user validation with a email and username

     validates :username, :email, presence: true  
     validates :username, :email, uniqueness: true

a user is created when signing up which is done through the form i also crates a user session which is then deleted upon logging out a user can login persisting that session

get '/signup' do   
    erb :'users/signup' 
   end  
 
post '/signup' do    @user = User.new(params)
     if @user.save        
     session[:user_id] = @user.id      
     redirect '/songs'   
   else     
     redirect '/signup'    
   end  
end
   
get '/login' do 
   flash[:login] = "Have An Account?"
    erb :'users/login'
  end
   
post '/login' do
#make sure email exists in db    
   @user = User.find_by(username:params[:username])
#check if password is valid
    if @user && @user.authenticate(params[:password])
        session[:user_id] = @user.id
          flash[:login] = "Login Successful!"
        redirect "/songs"
    else
flash[:login] = "Please Enter A Valid Username/Password, Or Simply Create An Account"       
 redirect "/login"    
  end  
end

once logged in a user can create a song edit that song and delete that song

#creates a song
  post '/songs' do
    @song = Song.new(params)
    @song.user_id = session[:user_id]   

    if @song.save 
      redirect to "/songs/#{@song.id}"
    else 
     redirect '/songs'
    end
  end 
  #updates a song
  patch '/songs/:id' do
   @song = Song.find_by_id(params[:id])
    @song.title = params[:title]
    @song.artist = params[:artist]
    @song.genre = params[:genre] 
   @song.save 
   redirect to "/songs/#{@song.id}"
  end
   #destroys a song
  delete '/songs/:id' do
    # binding.pry
    @song = Song.find_by_id(params[:id])
    @song.delete    redirect to '/songs'
  end

a user can edit themselves (email, username)

get '/users/:id/edit'
 do 
   @user = User.find_by_id(params[:id])
    if @user
      erb :'users/edit'
    else
      redirect to "/users/:id"
    end
  end
   get '/users/:id'
 do
    redirect to '/songs'
  end 
  patch '/users/:id'
 do 
     @user = User.find_by_id(params[:id])
      if @user && @user.authenticate(params[:user][:password])
      @user.username = params[:username]
        @user.email = params[:email] 
       @user.save
        redirect to "/users/#{@user.id}"
      else
        redirect to "/users/#{@user.id}/edit"
      end

the only way to do this successfully would be to input their original password otherwise it won’t persist to the database