Project create

app/controllers/projects_controller.rb

@@ -8,11 +8,24 @@ class ProjectsController < ApplicationController
   def show
   end
 
+  def new
+    @project = Project.new
+  end
+
+  def create
+    @project = Project.new(project_params)
+    if @project.save
+      redirect_to @project
+    else
+      render :new, status: :unprocessable_entity
+    end
+  end
+
   def edit
   end
 
   def update
-    if @project.update(params.expect(project: %i[code name description]))
+    if @project.update(project_params)
       redirect_to @project
     else
       render :edit, status: :unprocessable_entity
@@ -27,4 +40,8 @@ class ProjectsController < ApplicationController
   def fetch_project!
     @project = Project.find_by!(code: params[:id])
   end
+
+  def project_params
+    params.expect(project: %i[code name description])
+  end
 end

app/models/project.rb

@@ -1,12 +1,23 @@
 class Project < ApplicationRecord
   validates :name, :code, presence: true
+  validates :code, exclusion: { in: %w[new] }, uniqueness: true
 
   has_many :tasks
 
   has_rich_text :description
 
+  before_validation :lowercase_code
+
   def to_param
     return unless id
     code
   end
+
+  private
+
+  def lowercase_code
+    return if code.blank?
+
+    self.code = self.code.downcase
+  end
 end

app/views/projects/new.html.slim

@@ -0,0 +1,3 @@
+h1 New project
+
+= render 'form'