配置authlogic以"用户名"或"电子邮件"登录

gem 'authlogic'

class User < ApplicationRecord
  acts_as_authentic do |c|
    c.login_field = :username # 设置登录字段为用户名
    # 或者
    c.login_field = :email # 设置登录字段为电子邮件
  end
end

<%= form_for @user_session do |f| %>
  <%= f.label :login %>
  <%= f.text_field :login %>

  <%= f.label :password %>
  <%= f.password_field :password %>

  <%= f.submit "登录" %>
<% end %>

class UserSessionsController < ApplicationController
  def new
    @user_session = UserSession.new
  end

  def create
    @user_session = UserSession.new(user_session_params)
    if @user_session.save
      redirect_to root_path, notice: "登录成功"
    else
      render :new
    end
  end

  def destroy
    current_user_session.destroy
    redirect_to root_path, notice: "已注销"
  end

  private

  def user_session_params
    params.require(:user_session).permit(:login, :password)
  end
end