Nested Ticket Edit Action Comes Up Blank Inside Project - ruby-on-rails

Question

I am building a rails app to learn about nested controllers actions. Hence I have Projects to which Tickets are nested underneath. It's basically a rip-off from Rails Action. Now, I am trying to add edit action in Ticket's controller.
Everything works fine in Projects, ie, all the actions.
Everything seems to work fine in Tickets. As stated earlier, it's a rip-off from Rails Action. So trying learn how to put in correct stuff within blank actions, ie, Edit, Show, Update, and Destroy
When I added edit action in Tickets show page, and clicked on it, it showed the page, but the form fields are blank.
The url path is correct: http://127.0.0.1:3000/projects/2/tickets/2/edit so that means the resources are set up correctly.
How do I fix this so it shows the previous content? My vague understanding is that it may have to do with the form?
Current Tickets Controller
class TicketsController < ApplicationController
#which actions are necessary? learn how to not need set_project set_ticket
before_action :set_project
before_action :set_ticket, only: [:show, :edit, :update, :destroy]
def create
#ticket = #project.tickets.build(ticket_params)
if #ticket.save
flash[:notice] = "Ticket has been created."
redirect_to project_path(#project)
else
flash.now[:alert] = "Ticket has not been created."
render "new"
end
end
def new
#ticket = #project.tickets.build
end
def show
end
def edit
#ticket = #project.tickets.find(params[:id])
end
def update
end
def destroy
end
private
def ticket_params
params.require(:ticket).permit(:title, :description)
end
def set_project
#project = Project.find(params[:project_id])
end
def set_ticket
#ticket = #project.tickets.find(params[:id])
end
end
show.html.erb - Ticket
<h1><%= #project.title %></h1>
<h3><%= #ticket.title %></h3>
<%= link_to "All Projects", projects_path %>
<%= link_to "Edit Ticket", edit_project_ticket_path %>
_form.html.erb - Ticket
<%= form_for([#project, #project.tickets.build]) do |f| %>
<p>
<%= f.label :title %><br/>
<%= f.text_field :title %>
</p>
<p>
<%= f.label :description %><br />
<%= f.text_area :description %>
</p>
<p>
<%= f.submit %>
</p>
<% end %>
EDIT, I've updated the _form.html.erb to the following code beneath, and it seems to work, ie, it shows the contents to modify. Yay. But when I click on Update Ticket button, it doesn't move beyond the page.
<%= form_for [#project,#ticket] do |f| %>
EDIT AGAIN
I updated the ticket's controller actions for Show and Update, and now it seems to work! Including it for feedback in case this was done incorrectly.
class TicketsController < ApplicationController
#which actions are necessary? learn how to not need set_project set_ticket
before_action :set_project
before_action :set_ticket, only: [:show, :edit, :update, :destroy]
def create
#ticket = #project.tickets.build(ticket_params)
if #ticket.save
flash[:notice] = "Ticket has been created."
redirect_to project_path(#project)
else
flash.now[:alert] = "Ticket has not been created."
render "new"
end
end
def new
#ticket = #project.tickets.build
end
def show
#ticket = #project.tickets.find(params[:id])
end
def edit
#ticket = #project.tickets.find(params[:id])
end
def update
if #ticket.update(ticket_params)
flash[:notice] = "Ticket has been updated."
redirect_to [#project, #ticket]
else
flash.now[:alert] = "Ticket has not been updated."
render "edit"
end
end
def destroy
end
private
def ticket_params
params.require(:ticket).permit(:title, :description)
end
def set_project
#project = Project.find(params[:project_id])
end
def set_ticket
#ticket = #project.tickets.find(params[:id])
end
end