How do I update a foreign key via Views (UI)?

Rails
#1

Hi all,

I am having an issue here that i seem not to wrap my head around… I am
making a simple online catalog…

I have 2 models Category and LineItems
where Category has many LineItems

So in the LineItem Model I say:

class LineItem < ActiveRecord::Base
belongs_to :category

Now in my edit form (View) for LineItem called edit.rhtml, with a drop
down list, I wish to select the category and update it in the database.

For that I use the following before the scaffolding code in the (this is
a simple test app I am doing here…).

<%=
@categories = Category.find(:all, :order => “name”).map {|c| [c.name,
c.id]}
select(:category, :id, @categories)
%>

Items come up ok but I cannot seem to update. I believe the select
parameters are ok but could the problem be there or am I missing
something ?
Note that when I use the Edit view, I wish to read the existing
category_id and have it pre-selected for me if it already exists.

TIA,
Tuka

#2

Please post your corresponding controller code.

  • Roderick
#3

Your controller code seems in order and I just noticed that it’s your
select() statement that needs adjustment. Try:

select(:line_item, :category_id, @categories)

  • Roderick
#4

Here goes… the full listing so that we miss nothing:

class ItemController < ApplicationController
layout ‘home’

def index
list
render :action => ‘list’
end

GETs should be safe (see

http://www.w3.org/2001/tag/doc/whenToUseGet.html)
verify :method => :post, :only => [ :destroy, :create, :update ],
:redirect_to => { :action => :list }

def list
@line_item_pages, @line_items = paginate :line_items, :conditions =>
["category_id = ? ",params[:id]],:per_page => 10
end

def admin_list
@line_item_pages, @line_items = paginate :line_items, :conditions =>
["category_id = ? ",params[:id]],:per_page => 10
end

def show
@line_item = LineItem.find(params[:id])
end

def new
@line_item = LineItem.new
end

def create
@line_item = LineItem.new(params[:line_item])
if @line_item.save
flash[:notice] = ‘LineItem was successfully created.’
redirect_to :action => ‘list’
else
render :action => ‘new’
end
end

def edit
@line_item = LineItem.find(params[:id])
end

def update
@line_item = LineItem.find(params[:id])
if @line_item.update_attributes(params[:line_item])
flash[:notice] = ‘LineItem was successfully updated.’
redirect_to :action => ‘show’, :id => @line_item
else
render :action => ‘edit’
end
end

def destroy
LineItem.find(params[:id]).destroy
redirect_to :action => ‘list’
end
end

#5

Roderick, Hurray !!

Not only your indication was correct, it helped me find another error,
that the select code was not within the ROR start_form_tag and thus

in the resulting page - thats is why it was not writing/reading to the DB.

Thank a ton for your time and pointing me in the right direction !!

Cheers,
Tuka