I’m building an app for displaying events information.
The app has a database of bands, and events
an event can have many bands, and a band can have many events, so I’ve
gone for a has_and_belongs_to_many association between the two models,
with the join table bands_events.
In order to be able to dynamically add bands, I’ve refactored the ‘add a
band’ part of the form into a partial called _band, this form has 2
parts, a text_field to enter the name of a new band, or a
collection_select drop down select box to select a band already stored.
The idea is that you can make a new band on the fly by typing into the
text_field, or you select an existing one from the menu.
The text field is working fine, and creates new associated bands, but
the collection_select selection isn’t getting passed through correctly,
and I’m very confused…
(I got the code from R Bates’s railscast on complex forms pt 2)
my controller initialises the band into memory
EventsController
def new
@event = Event.new
@bands = Band.order(’“band_name” ASC ')
1.times {@event.bands.build}
end
The views are currently very simple ( in haml if you’re thinking it
looks weird!)
---------------------------- new.html.haml
%h1 Create a new event
=form_for [:events_admin, @event], :url => events_admin_events_path,
:html => { :multipart => true } do |f|
=render :partial=>“events_form”, :locals=>{:event => @event, :f=>f}
---------------- _events_form.html.haml
%fieldset
.half
=f.label “Event Name”
=f.text_field :event_name
=render :partial => "band", :collection => @event.bands
=f.submit "Save Event"
----------------- _band.html.haml
=fields_for “event[band_attributes][]”, band do |band_form|
=band_form.label “Add a new band”
=band_form.text_field :new_band_name
// This is not working at all, for some reason the params are not
being passed through
=band_form.label “Select from saved Bands”
=collection_select(band, :saved_band_name, @bands, :band_name,
:band_name, {:selected => @selected_band})
when the submit button is pressed, the method band_attributes= is called
in the Event model class, and that looks like this:
event.rb - class Event < ActiveRecord::Base
def band_attributes=(band_attributes)
band_attributes.each do |attributes|
new_band_name = attributes[:new_band_name]
logger.debug"______NEW BAND NAME FROM PARAMS _______"
logger.debug(new_band_name)
if new_band_name.empty?
saved_band_name = attributes[:saved_band_name]
band_object = Band.where(:band_name => saved_band_name)[0]
logger.debug"______ BAND NAME FROM PARAMS DROP DOWN LIST
_______"
logger.debug(saved_band_name)
else
attributes[:band_name] = new_band_name
bands.build(attributes)
end
end
end # of band_attributes
Typing into the text_field works fine, the new_band_name gets passed
through, and saved, but the saved_band_name from the collection select
drop down list does not get passed through in the band_attributes.
From looking at the logs, it looks like the ‘saved_band_name’ parameter
is not getting grouped with the other band data
LOGS:
Parameters: {“commit”=>“Save Event”,
“authenticity_token”=>“bRJcMHn+PL3pwpeVcgyUpd/IgRjNiGih2cfadZoPJSk=”,
“utf8”=>“✓”, “#Band:0x1049e4008”=>{“saved_band_name”=>“A BAND I’VE
SAVED”}, “event”=>{“band_attributes”=>[{“new_band_name”=>""}],
“start_time(1i)”=>“2011”, “music_sample_link”=>""………
Does anyone know what is going on here, and how I can get the parameter
from the collection_select box to be passed in the same hash as the
new_band_name??
All help appreciated massively.
Mike