Using accepts_nested_attributes_for on a join table with its own attributes - Duplicate rows
https://stackoverflow.com/questions/4279028
-
28-09-2019 - |
italiano
english
français
española
中国
日本の
العربية
Deutsch
한국어
Português
RussianQuestion
I have the following three models (Rails 2.3.8)
class Outbreak < ActiveRecord::Base
has_many :incidents, :dependent => :destroy
has_many :locations, :through => :incidents
accepts_nested_attributes_for :incidents, :allow_destroy => true
accepts_nested_attributes_for :locations, :allow_destroy => true, :reject_if => proc { |attrs| attrs.all? { |k, v| v.blank? } }
end
class Incident < ActiveRecord::Base
belongs_to :outbreak
belongs_to :location
end
class Location < ActiveRecord::Base
has_many :incidents
has_many :outbreaks, :through => :incidents
accepts_nested_attributes_for :incidents, :allow_destroy => true
end
The parameters from the form seem to be ok
"outbreak"=>{ "locations_attributes"=>{"0"=>{"lon"=>"-1.39", "placename"=>"wetwe", "hpu_id"=>"15", "postcode"=>"so1 1aa", "region_id"=>"10", "address_1"=>"", "town"=>"Bargate", "address_2"=>"", "address_3"=>"", "lat"=>"50.89"}},"incidents_attributes"=>{"0"=>{"subtype_id"=>"7", "category_id"=>"1", "detail"=>"", "subcategory_id"=>"2"}} }
But when the Outbreak is saved 3 rows are created in the Incidents table (the join table) and a single row in the Outbreak and Location tables.
The rows in the Incidents table are not fully populated from the params as follows:
id outbreak_id location_id category_id subcategory_id subtype_id detail created_at updated_at
57 23 NULL 1 2 7 2010-11-25 14:45:18.385905 2010-11-25 14:45:18.385905
58 23 27 NULL NULL NULL NULL 2010-11-25 14:45:18.39828 2010-11-25 14:45:18.39828
59 23 27 NULL NULL NULL NULL 2010-11-25 14:45:18.403051 2010-11-25 14:45:18.403051
This must be due to the either the format of the parameters or the multiple accepts_nested_attributes_for methods - how do I have just a single row being entered in the Incidents table with all of the parameters information?
Solution
Second time so far this week I've answered my own question ^^ that'll teach me to put more effort in before giving up and posting on the net for help,
Still after looking at my original question I didn't include enough information to answer it properly - the issue (apart from the set up of the models) was down to the Outbreak constructor in the Outbreak controller new method,
Original Outbreaks_controller
def new
@outbreak = Outbreak.new
@outbreak.risks.build
//links locations directly to Outbreak instead of through Incidents
@outbreak.locations.build
@outbreak.incidents.build
respond_to do |format|
format.html # new.html.erb
format.xml { render :xml => @outbreak }
end
end
Revised Outbreaks_controller
def new
@outbreak = Outbreak.new
@outbreak.risks.build
//builds Incidents then a Location through that incident
@outbreak.incidents.build.build_location
respond_to do |format|
format.html # new.html.erb
format.xml { render :xml => @outbreak }
end
end
Changes to the three models
class Outbreak < ActiveRecord::Base
has_many :incidents, :dependent => :destroy
has_many :locations, :through => :incidents
accepts_nested_attributes_for :incidents, :allow_destroy => true
end
class Incident < ActiveRecord::Base
belongs_to :outbreak
belongs_to :location
accepts_nested_attributes_for :location, :allow_destroy => true
end
class Location < ActiveRecord::Base
has_many :incidents
has_many :outbreaks, :through => :incidents
end
This seems to work ok - also posted the create action and main form
OTHER TIPS
The create action only needs the nested params provided for :outbreak (the models do the work).
def create
@outbreak = Outbreak.new(params[:outbreak])
@outbreak.user_id = current_user.id
respond_to do |format|
if @outbreak.save
flash[:notice] = 'Outbreak was successfully created.'
format.html { redirect_to(@outbreak) }
format.xml { render :xml => @outbreak, :status => :created, :location => @outbreak }
else
format.html { render :action => "new" }
format.xml { render :xml => @outbreak.errors, :status => :unprocessable_entity }
end
end
end
The outbreak form is pretty long so I've cut it down to the two sections mentioned (although there's probably more attributes and fields here than is need to get an idea).
An example of the HTML element id for the nested fields can be found at the bottom in the Javascript observe_field helper. A post I made on AJAX updates of nested_attributes_for partials might also be useful AJAX update of accepts_nested_attributes_for
<% form_for(@outbreak, :html => {:multipart => true}) do |form| %>
<%= form.error_messages %>
<div id="tabs">
<ul>
<li ><a href="#tabs_b">Outbreak</a></li>
<li ><a href="#tabs_c">Location</a></li>
</ul>
<div id="tabs_b">
<fieldset id="b" class="form_div">
<legend>Outbreak</legend>
<fieldset>
<legend>References</legend>
<div class="left_form">
<%= form.label :user_reference %>
</div>
<div class="right_form">
<%= form.text_field :user_reference %>
</div>
<div style="clear:both;"></div>
</fieldset>
</fieldset>
</div>
<div id="tabs_c">
<fieldset id="c" class="form_div" >
<legend>Location</legend>
<div id="location_error"></div>
<fieldset>
<legend>Setting</legend>
<% form.fields_for :incidents do |incident_form| %>
<div class="left_form">
<%= incident_form.label :category_id %>
</div>
<div class="right_form">
<div id="incident_category_select">
<%= render :partial => 'category_select', :locals => {:categories => @categories, :incident_form => incident_form} %>
</div>
</div>
<div style="clear:both;"></div>
<div class="left_form">
<%= incident_form.label :subcategory_id %>
</div>
<div class="right_form">
<div id="incident_subcategory_select">
<%= render :partial => 'subcategory_select', :locals => { :subcategories => @subcategories, :incident_form => incident_form } %>
</div>
</div>
<div style="clear:both;"></div>
<div class="left_form">
<%= incident_form.label :subtype_id %>
</div>
<div class="right_form">
<div id="incident_subtype_select">
<%= render :partial => 'subtype_select', :locals => { :subtypes => @subtypes, :incident_form => incident_form } %>
</div>
</div>
<div style="clear:both;"></div>
<div id="cuisine_div">
<% if @outbreak.outbreak_type == "FOODBORNE" %>
<div class="left_form">
<%= label :incident, :cuisine_id %>
</div>
<div class="right_form">
<% cuisine_select = (@incident != nil ? @incident.cuisine_id.to_i : '') %>
<%= incident_form.select( :cuisine_id, "<option value='' >Please select</option>" + options_from_collection_for_select(@cuisines, :id, :name, cuisine_select)) %>
</div>
<% end %>
</div>
<div style="clear:both;"></div>
<div class="left_form">
<%= incident_form.label :detail %>
</div>
<div class="right_form">
<%= incident_form.text_field :detail %>
</div>
</fieldset>
<fieldset>
<legend>Details</legend>
<% incident_form.fields_for :location do |location_form| %>
<div style="clear:both;"></div>
<div class="left_form">
<%= location_form.label :placename %>
</div>
<div class="right_form">
<%= location_form.text_field :placename %>
</div>
<div style="clear:both;"></div>
<div class="left_form">
<%= location_form.label :address_1 %>
</div>
<div class="right_form">
<%= location_form.text_field :address_1 %>
</div>
<div style="clear:both;"></div>
<div class="left_form">
<%= location_form.label :address_2 %>
</div>
<div class="right_form">
<%= location_form.text_field :address_2 %>
</div>
<div style="clear:both;"></div>
<div class="left_form">
<%= location_form.label :address_3 %>
</div>
<div class="right_form">
<%= location_form.text_field :address_3 %>
</div>
<div style="clear:both;"></div>
<div class="left_form">
<%= location_form.label :town %>
</div>
<div class="right_form">
<%= location_form.text_field :town %>
</div>
<div style="clear:both;"></div>
<div class="left_form">
<%= location_form.label :postcode %>
</div>
<div class="right_form">
<%= location_form.text_field :postcode %>
</div>
<div style="clear:both;"></div>
<div class="left_form">
<%= location_form.label :region_id %>
</div>
<div class="right_form" >
<% region_select = (@location != nil ? @location.region_id.to_i : '') %>
<%= location_form.select(:region_id, "<option value=''>Select a region</option>" + options_from_collection_for_select(@regions, :id, :name, region_select)) %>
</div>
<div style="clear:both;"></div>
<div class="left_form">
<%= location_form.label :hpu_id %>
</div>
<div class="right_form" >
<% hpu_select = (@location != nil ? @location.hpu_id.to_i : '') %>
<%= location_form.select(:hpu_id, "<option value=''>Select a HPU</option>" + options_from_collection_for_select(@hpus, :id, :name, hpu_select)) %>
</div>
<div style="clear:both;"></div>
<%= location_form.hidden_field :lon, :value => '' %>
<%= location_form.hidden_field :lat, :value => '' %>
<%= hidden_field_tag :postcode_error, :value => '0' %>
<% end %>
</fieldset>
<% end %>
</fieldset>
</div>
</div>
<% end %>
<div style="clear: both; margin: 10px;"></div>
<%= observe_field(:outbreak_incidents_attributes_0_location_attributes_postcode,
:url => { :controller => :locations, :action => :find_lonlat },
:on => "onchange",
:loading => "Element.show('loader')",
:success => "Element.hide('loader')",
:with => "'postcode=' + encodeURIComponent($('outbreak_incidents_attributes_0_location_attributes_postcode').value)" ) %>
