Rails - Oct 2009 - Problems Processing multiple form elements generated by javascript actions

Hi all,

After many days of struggling, I have a multi-model form with ajax
elements more or less working, but I''m hitting a wall with a few bugs
that I can''t figure out.  Guidance would be very much appreciated.

I''m using the Ryan Bates technique from Advanced Rails recipes to
dynamically add and remove elements on a multi-model form.
http://media.pragprog.com/titles/fr_arr/multiple_models_one_form.pdf

I have 3 models: users, schedules and markets.
Users
has_many :schedules
has_many :markets, :through => :schedules

Markets
has_many :schedules
has_many :users, :through => :schedules

Schedules
belongs_to :users
belongs_to :markets

Schedules has columns user_id and market_id, but also has additional
columns: monday, tuesday, wednesday, thursday, friday, saturday,
sunday. These are booleans.

All the editing in my app happens from the user model. The list of
available markets are prepopulated in the app, and the user cannot add
new ones. On the user#edit view, I''m showing the user a dropdown for
each of his existing markets and for each market, I''m rendering 7
checkboxes representing each day of the week. The goal is that each
market selected and its associated selected dates should be saved as a
"schedule" record in the schedules table. The row in that table should
contain a user_id, a market_id, and each selected day of the week as
true. When a user removes a market from the edit page, then that
schedule row should be destroyed.

As discussed in Ryan''s tutorial, there are issues regarding new vs.
existing data. I''m running into one of these. I''m also having
problems
with deleting records. I''m going to explain my issues and then lay out
my full set up below.

New vs. existing data: The schema I explained above is mostly working.
However, I''m having issues when the user selects a new market AND
selects some checkboxes to indicate the days he attends. Using the
technique described below, I have an "add new schedule" link that
dynamically generates a market dropdown along with seven checkboxes
for the dates. This works fine. I can select one of my markets and
check off some days. However, when I click update, these inputs save
as multiple records in the schedules table. The market_id, user_id and
monday=false save as one row. Then, for each checkbox that I selected,
the user_id and day save as a row. So if I select 3 days, then I get 4
new records: one for the market and one for each data checked.

Here''s the part about new vs. existing data: When I go back to the
edit page, I see the correct market in one dropdown with no checkboxes
selected and then one additional empty dropdown with one checkbox
selected for each checkbox that the user selected before hitting
update. Now that the schedule is an "existing" record, when I check
off some days associated with the dropdown where the market is
selected, and I hit "update", these save perfectly and render
correctly on the user#show page. So basically, the edit/update action
is working perfectly and the creation of new schedules is not.  The
problem is really just the checkboxes because the market actually
saves correctly.  One solution I tried was to add something like the
following to each check_box method, but this blew up the app: :index
=> (showing.new_record? ? '''' : nil).  This is problem #1.

Problem #2 is that when I click the "remove" link for a given schedule
(i.e. a market and its 7 available checkboxes combination, and I hit
update, the user_id and market_id are properly deleted from the
schedules table. However, the record itself is not deleting and the
boolean fields representing the days of the week remain as well. I''m
able to hack around this and technically the app works because these
half-empty rows aren''t associated with any of my models, but
I''m
quickly building up a database table filled with orphaned, useless
data. Ideally, when I delete a "schedule" record, I''d like it
to be
destroyed.

The following is my setup. You''ll see that I''m following
Ryan''s
tutorial very closely. One area where I depart from it is the
checkboxes, which I implemented based on the Rails API fields_for
method examples.

User#Edit view:

<%= error_messages_for :user %>
  <% form_for @user do |f| %>
    <%= add_schedule_link "+ Add another market" %>
    <div id="schedules">
      <%= render :partial => ''schedule'', :collection
=>
@user.schedules %>
  </div>
   <%= f.submit ''Update My Profile'' %>
<% end %>

User#_schedule.html.erb

<div class="schedule">
   <% new_or_existing = schedule.new_record? ? ''new'' :
''existing'' %>
   <% prefix = "user[#{new_or_existing}_schedule_attributes][]"
%>

   <% fields_for prefix, schedule do |schedule_form| -%>
     <%= error_messages_for :schedule, :object => schedule %>
       <p><%= schedule_form.collection_select :market_id,
Market.all, :id, :name, {:prompt => true} %></p>
       <p><%= link_to_function "- Remove Market",
"$(this).up
(''.schedule'').remove()" %></p>
       <%= schedule_form.check_box :monday %>
       <%= schedule_form.check_box :tuesday %>
       <%= schedule_form.check_box :wednesday %>
       <%= schedule_form.check_box :thursday %>
       <%= schedule_form.check_box :friday %>
       <%= schedule_form.check_box :saturday %>
       <%= schedule_form.check_box :sunday %>
    <% end -%>
</div>

User Model:

validates_associated :schedules, :on => :update
after_update :save_schedules

  accepts_nested_attributes_for :schedules, :allow_destroy => :true,
      :reject_if => :all_blank

  def new_schedule_attributes=(schedule_attributes)
    schedule_attributes.each do |attributes|
      schedules.build(attributes)
    end
  end

  def existing_schedule_attributes=(schedule_attributes)
    schedules.reject(&:new_record?).each do |schedule|
      attributes = schedule_attributes[schedule.id.to_s]
      if attributes
        schedule.attributes = attributes
      else
        schedules.delete(schedule)
      end
    end
  end

  def save_schedules
    schedules.each do |schedule|
      schedule.save(false)
    end
  end

User Controller

def new
  @user = User.new
end

def create
  cookies.delete :auth_token
  @user = User.new(params[:user])
  @user.save!
  flash[:notice] = "Thanks for signing up! Please check your email to
activate your account before logging in."
  redirect_to login_path
rescue ActiveRecord::RecordInvalid
  flash[:error] = "There was a problem creating your account."
  render :action => ''new''
end

def edit
  @user = current_user
end

def update
  params[:user][:existing_schedule_attributes] ||= {}
  params[:user][:existing_season_attributes] ||= {}

  @user = User.find(current_user)
    if @user.update_attributes(params[:user])
      flash[:notice] = "Your information has been updated."
      redirect_to :action => ''show'', :id => current_user
    else
      render :action => ''edit''
    end
end

def destroy
    @user = User.find(params[:id])
    if @user.update_attribute(:enabled, false)
      flash[:notice] = "User disabled"
    else
      flash[:error] = "There was a problem disabling this user."
    end
    redirect_to :back #action => ''index''
  end

Helpers: users_helper.rb

module UsersHelper
def add_schedule_link(name)
    link_to_function name do |page|
    page.insert_html :bottom, :schedules, :partial =>
''schedule'', :object => Schedule.new
  end
end

end

As a quick follow up, it looks like the first problem I''m facing is
because of the checkboxes.  Ryan actually states at the end of his
chapter in Rails Recipes that checkboxes won''t work because their
value is not passed by the browser when the box is unchecked.  So you
cannot tell which market a given checkbox belongs to when a new
schedule record is created.  His solution is to use a select menu for
boolean fields, where No =false and Yes = true.  I tried that and it
does fix my problem.  However, I''d prefer to use checkboxes if
there''s
a way around this.

My second problem regarding destroying schedule records still remains
outstanding.

Thanks,
Mike

On Oct 6, 3:06 am, Mike
<mikeho...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> Hi all,
>
> After many days of struggling, I have a multi-model form with ajax
> elements more or less working, but I''m hitting a wall with a few
bugs
> that I can''t figure out.  Guidance would be very much appreciated.
>
> I''m using the Ryan Bates technique from Advanced Rails recipes to
> dynamically add and remove elements on a multi-model
form.http://media.pragprog.com/titles/fr_arr/multiple_models_one_form.pdf
>
> I have 3 models: users, schedules and markets.
> Users
> has_many :schedules
> has_many :markets, :through => :schedules
>
> Markets
> has_many :schedules
> has_many :users, :through => :schedules
>
> Schedules
> belongs_to :users
> belongs_to :markets
>
> Schedules has columns user_id and market_id, but also has additional
> columns: monday, tuesday, wednesday, thursday, friday, saturday,
> sunday. These are booleans.
>
> All the editing in my app happens from the user model. The list of
> available markets are prepopulated in the app, and the user cannot add
> new ones. On the user#edit view, I''m showing the user a dropdown
for
> each of his existing markets and for each market, I''m rendering 7
> checkboxes representing each day of the week. The goal is that each
> market selected and its associated selected dates should be saved as a
> "schedule" record in the schedules table. The row in that table
should
> contain a user_id, a market_id, and each selected day of the week as
> true. When a user removes a market from the edit page, then that
> schedule row should be destroyed.
>
> As discussed in Ryan''s tutorial, there are issues regarding new
vs.
> existing data. I''m running into one of these. I''m also
having problems
> with deleting records. I''m going to explain my issues and then lay
out
> my full set up below.
>
> New vs. existing data: The schema I explained above is mostly working.
> However, I''m having issues when the user selects a new market AND
> selects some checkboxes to indicate the days he attends. Using the
> technique described below, I have an "add new schedule" link that
> dynamically generates a market dropdown along with seven checkboxes
> for the dates. This works fine. I can select one of my markets and
> check off some days. However, when I click update, these inputs save
> as multiple records in the schedules table. The market_id, user_id and
> monday=false save as one row. Then, for each checkbox that I selected,
> the user_id and day save as a row. So if I select 3 days, then I get 4
> new records: one for the market and one for each data checked.
>
> Here''s the part about new vs. existing data: When I go back to the
> edit page, I see the correct market in one dropdown with no checkboxes
> selected and then one additional empty dropdown with one checkbox
> selected for each checkbox that the user selected before hitting
> update. Now that the schedule is an "existing" record, when I
check
> off some days associated with the dropdown where the market is
> selected, and I hit "update", these save perfectly and render
> correctly on the user#show page. So basically, the edit/update action
> is working perfectly and the creation of new schedules is not.  The
> problem is really just the checkboxes because the market actually
> saves correctly.  One solution I tried was to add something like the
> following to each check_box method, but this blew up the app: :index
> => (showing.new_record? ? '''' : nil).  This is problem
#1.
>
> Problem #2 is that when I click the "remove" link for a given
schedule
> (i.e. a market and its 7 available checkboxes combination, and I hit
> update, the user_id and market_id are properly deleted from the
> schedules table. However, the record itself is not deleting and the
> boolean fields representing the days of the week remain as well.
I''m
> able to hack around this and technically the app works because these
> half-empty rows aren''t associated with any of my models, but
I''m
> quickly building up a database table filled with orphaned, useless
> data. Ideally, when I delete a "schedule" record, I''d
like it to be
> destroyed.
>
> The following is my setup. You''ll see that I''m following
Ryan''s
> tutorial very closely. One area where I depart from it is the
> checkboxes, which I implemented based on the Rails API fields_for
> method examples.
>
> User#Edit view:
>
> <%= error_messages_for :user %>
>   <% form_for @user do |f| %>
>     <%= add_schedule_link "+ Add another market" %>
>     <div id="schedules">
>       <%= render :partial => ''schedule'',
:collection =>
> @user.schedules %>
>   </div>
>    <%= f.submit ''Update My Profile'' %>
> <% end %>
>
> User#_schedule.html.erb
>
> <div class="schedule">
>    <% new_or_existing = schedule.new_record? ? ''new'' :
''existing'' %>
>    <% prefix =
"user[#{new_or_existing}_schedule_attributes][]" %>
>
>    <% fields_for prefix, schedule do |schedule_form| -%>
>      <%= error_messages_for :schedule, :object => schedule %>
>        <p><%= schedule_form.collection_select :market_id,
> Market.all, :id, :name, {:prompt => true} %></p>
>        <p><%= link_to_function "- Remove Market",
"$(this).up
> (''.schedule'').remove()" %></p>
>        <%= schedule_form.check_box :monday %>
>        <%= schedule_form.check_box :tuesday %>
>        <%= schedule_form.check_box :wednesday %>
>        <%= schedule_form.check_box :thursday %>
>        <%= schedule_form.check_box :friday %>
>        <%= schedule_form.check_box :saturday %>
>        <%= schedule_form.check_box :sunday %>
>     <% end -%>
> </div>
>
> User Model:
>
> validates_associated :schedules, :on => :update
> after_update :save_schedules
>
>   accepts_nested_attributes_for :schedules, :allow_destroy => :true,
>       :reject_if => :all_blank
>
>   def new_schedule_attributes=(schedule_attributes)
>     schedule_attributes.each do |attributes|
>       schedules.build(attributes)
>     end
>   end
>
>   def existing_schedule_attributes=(schedule_attributes)
>     schedules.reject(&:new_record?).each do |schedule|
>       attributes = schedule_attributes[schedule.id.to_s]
>       if attributes
>         schedule.attributes = attributes
>       else
>         schedules.delete(schedule)
>       end
>     end
>   end
>
>   def save_schedules
>     schedules.each do |schedule|
>       schedule.save(false)
>     end
>   end
>
> User Controller
>
> def new
>   @user = User.new
> end
>
> def create
>   cookies.delete :auth_token
>   @user = User.new(params[:user])
>   @user.save!
>   flash[:notice] = "Thanks for signing up! Please check your email to
> activate your account before logging in."
>   redirect_to login_path
> rescue ActiveRecord::RecordInvalid
>   flash[:error] = "There was a problem creating your account."
>   render :action => ''new''
> end
>
> def edit
>   @user = current_user
> end
>
> def update
>   params[:user][:existing_schedule_attributes] ||= {}
>   params[:user][:existing_season_attributes] ||= {}
>
>   @user = User.find(current_user)
>     if @user.update_attributes(params[:user])
>       flash[:notice] = "Your information has been updated."
>       redirect_to :action => ''show'', :id =>
current_user
>     else
>       render :action => ''edit''
>     end
> end
>
> def destroy
>     @user = User.find(params[:id])
>     if @user.update_attribute(:enabled, false)
>       flash[:notice] = "User disabled"
>     else
>       flash[:error] = "There was a problem disabling this user."
>     end
>     redirect_to :back #action => ''index''
>   end
>
> Helpers: users_helper.rb
>
> module UsersHelper
> def add_schedule_link(name)
>     link_to_function name do |page|
>     page.insert_html :bottom, :schedules, :partial =>
> ''schedule'', :object => Schedule.new
>   end
> end
>
> end