Nested Forms - fields_for() and symbols - ruby-on-rails

I've been struggling with this for the last several hours:
I have a nested form (shown below) and it's working, but for the life of me, I cannot figure how to access the :student_id in the _form_outcome_ratings.html.erb. It displays the appropriate student_id in the hidden field that's created, but I have no idea how to access that number to display the student's name next to the rating field. When I try to reference :student_id or :student_id.to_s it returns "student_id" instead of the number. I think I'm missing or misunderstanding something very basic, but I can't figure out what!
Thank you for taking the time to look at this, and let me know if there's anything I need to clarify or add.
/app/views/learning_outcomes/_form_rate.html.erb
<% form_for(#learning_outcome) do |f| %>
<% f.fields_for :outcome_ratings do |g| %>
<%= render :partial => 'form_outcome_ratings', :locals => {:f => g} %>
<% end %>
<%= f.submit %>
<% end %>
/app/views/learning_outcomes/_form_outcome_ratings.html.erb
<%= f.hidden_field :student_id %>
<%= f.label :rating %><%= f.text_field :rating %>
/app/controllers/learning_outcomes_controller.rb
def rate
#learning_outcome = LearningOutcome.find(params[:id], :include => {:section => {:students => {:outcome_ratings => [:learning_outcome, :student]}}})
#learning_outcome.section.students.each do |student|
#learning_outcome.outcome_ratings.build(:student_id => student.id) if student.outcome_ratings.where(:learning_outcome_id => #learning_outcome.id).blank?
end
end

Not sure I understod what you want, but...
You can access all variables of a model within a form builder if you do as follows:
f.object.your_variable
example:
f.object.id

Related

Rails check_box_tag within form_for

Is it possible to pass the value of checked check_box_tags within a form_for in Rails inside a hash?
Here is a very generic, basic version of the form:
<%= form_for(:object, :url => { :action => 'create', :id => params[:id]}) do |f| %>
<p>Field_a: <%= f.text_field(:field_a) %></p>
<p>Field_b: <%= f.text_field(:field_b) %></p>
<p>Field_c: <%= f.text_field(:field_c) %></p>
<p>Check boxes:</p>
<% check_box_choices_object_array.each do |s| %>
<%= check_box_tag(s.name, 1, false) %>
<%= .name %><br />
<% end %>
<%= submit_tag("Create") %>
<% end %>
Outputs roughly:
Field_a ___________________
Field_b ___________________
Field_c ___________________
Check boxes:
[] box_a
[] box_b
[] box_c
[] box_d
[] box_e
[] box_f
[] box_g
My problem is that since the available check boxes aren't actual fields in the object's table in the database (i.e. I'm not using check_box(:field) in the form), each checked check box gets passed as an individual parameter (i.e. "box_a" => "1", "box_b" => "1", "box_e" => "1"). I would like them to be passed as such:
:checked_boxes => {"box_a" => "1", "box_b" => "1", "box_e" => "1"}
This way, I can access them easily with params[:checked_boxes].
How do I do this, or, better yet, is there a better solution (I'm new to rails)?
I think you'd get the results you want if you wrap the checkboxes iterator in a fields_for :checked_boxes tag - or at least get you close to the results you want.
<%= form_for(:object, :url => { :action => 'create', :id => params[:id]}) do |f| %>
<p>Field_a: <%= f.text_field(:field_a) %></p>
<p>Field_b: <%= f.text_field(:field_b) %></p>
<p>Field_c: <%= f.text_field(:field_c) %></p>
<p>Check boxes:</p>
<%= f.fields_for :checked_boxes do |cb| %>
<% check_box_choices_object_array.each do |s| %>
<%= cb.check_box(s.name, 1, false) %>
<%= .name %><br />
<% end %>
<% end %>
<%= submit_tag("Create") %>
<% end %>
you can deal with no database attributes and models using attr_accessor
class Thing < ActiveRecord::Base
attr_accessible :name
attr_accessor :box_a, :box_b, :box_c
end
This way you can call these attributes in your form.

Drop-down menu in form with options from database with conditions? Rails 2.3.15

I'm writing a piece of an app that allows you to upload photos and assign them to a Bus. What I want is a drop-down menu with all the Name values. Buses can be either enabled or not. I'd like to restrict the list to just enabled buses. But I'm not sure how to do it in a form as a drop down menu.
This is all I know how to do:
<% Bus.find(:all, :conditions => {:is_enabled => 1).each do |bus| %>
<%= bus.name %>
<% end %>
But I don't know how to put this code in a form without it breaking in a variety of different ways, and I don't know any other way to get these names. This app uses an older version (Rails 2.3.15).
This was my best guess on how to do it:
<% form_for #bus_image, :html => { :multipart => true } do |f| -%>
<%= f.error_messages %>
<div class="field">
<%= f.label :name %><br />
<% Bus.find(:all, :conditions => {:is_enabled => 1}).each do |bus| %>
<%= select(bus.name) %>
<% end %>
<div>
<% end -%>
... which gives me wrong number of arguments (1 for 3).
Thanks, let me know if you need/want any more information.
Use this :
f.select(:bus_id, Bus.find(:all, :conditions => {:is_enabled => 1}).map{|b| [ b.name, b.id ] }, {:include_blank => true })
In place of :
<% Bus.find(:all, :conditions => {:is_enabled => 1}).each do |bus| %>
<%= select(bus.name) %>
<% end %>
Hope this will help.

Get an array from a Rails form

I need to design a form for a account resource. In that form, i need to collect some set of ids as an array in the params hash in attribute called relationships.
So the final params[account] hash from the POST request should be like:
{:name => 'somename', :relationships => ["123", "23", "23445"]}
How shall I design the form_for fields? I tried this, but didn't work:
<%= form_for #account do |f| %>
<%= f.text_field :name %>
<% #eligible_parents.each do |p| %>
<%= f.check_box "relationships", nil, :value => p.id %>
<b><%= p.name %></b><br/>
</span>
<% end %>
<%= f.submit "Submit" %>
<% end %>
Number of elements in #eligible_parents varies every time.
relationships is neither an association nor an attribute in account model.
I have to use virtual attributes but I need to fill in an array from a form.
Please help. How can I do this?
You still need a fields_for in your view, just use :relationships as the record_name then provide an object.
<%= form_for #account do |f| %>
<%= f.text_field :name %>
<% fields_for :relationships, #eligible_parents do |p| %>
<%= p.check_box "relationships", nil, :value => p.object.id %>
<b><%= p.object.name %></b><br/>
<% end %>
<%= f.submit "Submit" %>
<% end %>
Documentation here: ActionView::Helpers::FormHelper
I found this to be the cleanest way...
If you are working with straight data and want to send back an array without using any of these #objects:
<%= form_for :team do |t| %>
<%= t.fields_for 'people[]', [] do |p| %>
First Name: <%= p.text_field :first_name %>
Last Name: <%= p.text_field :last_name %>
<% end %>
<% end %>
your params data should return like this:
"team" => {
"people" => [
{"first_name" => "Michael", "last_name" => "Jordan"},
{"first_name" => "Steve", "last_name" => "Jobs"},
{"first_name" => "Barack", "last_name" => "Obama"}
]
}
If you want to send array of values just use [] in name attributes.In your case just use
<%= f.check_box "relationships", {}, :value => p.id, :name => "relationships[]" %>
In a complex form, with nested attributes, you can make use of the f.object_name helper. But beware of the syntax when doing interpolation. This is correct:
"#{f.object_name}[relationships][]"
This is NOT correct:
"#{f.object_name}[relationships[]]"
It always trips me up.
I'm working in something similar. My issue was how to pass the input name to a partial to resolve it as a hash using the rails form_for helper.
So, my solutions was something like this:
= render 'my_partial', form: form, name: "item_ids[item.id]"
So, this gonna render an html like this:
<input class="form-control" name="products[items_ids[1]]" id="products_items_ids[1]">
The number 1 is the item.id, this is how HTML understand that you gonna pass an array or hash, all depends your config.
So, the params gonna look like this:
"items_ids"=>{"1"=>"1"}
This is working for me with an form_object + virtus

Using observe_field on an field inside a fields_for

I'm trying to observe a field that get generated inside a fields_for loop.
The thing is that the id of that field is generated dynamically.
_form.html.erb
<% form_for #exp, :url => {:action => "update"} do |f| %>
<% f.fields_for:patterns do |builder| %>
<%= render 'pattern_fields', :f => builder %>
<% end %>
<% end %>
_pattern_fields.html.erb
Pattern: <%= f.select(:LC_PATTERN, [['stripes', 'stripes'],
['dots', 'dots'],
['lines', 'lines'],
],{ :prompt => "Please select"}
) %>
<%= observe_field("------", :frequency => 1,
:with => "'id='+value", :function => 'alert(value)')%>
My question is how do i get the id of the field inside the fields_for tag.
I finally got it. Found this solution on the internet...Hope it might be of help to someone else.
In your application_helper.rb, add the following functions:
def sanitized_object_name(object_name)
object_name.gsub(/\]\[|[^-a-zA-Z0-9:.]/,"_").sub(/_$/,"")
end
def sanitized_method_name(method_name)
method_name.sub(/\?$/, "")
end
def form_tag_id(object_name, method_name)
"#{sanitized_object_name(object_name.to_s)}_#{sanitized_method_name(method_name.to_s)}"
end
You can then view the id of the fields generated inside 'fields_for' by using the following code:
<%=form_tag_id(f.object_name, :LC_PATTERN) %>

Multiple forms for the same model in a single page

On the front page of my rap lyrics explanation site, there's a place where users can try explaining a challenging line:
alt text http://dl.dropbox.com/u/2792776/screenshots/2010-02-06_1620.png
Here's the partial I use to generate this:
<div class="stand_alone annotation" data-id="<%= annotation.id %>">
<%= song_link(annotation.song, :class => :title) %>
<span class="needs_exegesis"><%= annotation.referent.strip.gsub(/\n/, "\n <br />") %></span>
<% form_for Feedback.new(:annotation_id => annotation.id, :created_by_id => current_user.try(:id), :email_address => current_user.try(:email)), :url => feedback_index_path, :live_validations => true do |f| %>
<%= f.hidden_field :annotation_id %>
<%= f.hidden_field :created_by_id %>
<p style="margin-top: 1em">
<%= f.text_area :body, :rows => 4, :style => 'width:96%', :example_text => "Enter your explanation" %>
</p>
<p>
<% if current_user %>
<%= f.hidden_field :email_address %>
<% else %>
<%= f.text_field :email_address, :example_text => "Your email address" %>
<% end %>
<%= f.submit "Submit", :class => :button, :style => 'margin-left: .1em;' %>
</p>
<% end %>
</div>
However, putting more than one of these on a single page is problematic because Rails automatically gives each form an ID of new_feedback, and each field an ID like feedback_body (leading to name collisions)
Obviously I could add something like :id => '' to the form and all its fields, but this seems a tad repetitive. What's the best way to do this?
If you don't want to change your input names or your model structure, you can use the id option to make your form ID unique and the namespace option to make your input IDs unique:
<%= form_for Feedback.new(...),
id: "annotation_#{annotation.id}_feedback"
namespace: "annotation_#{annotation.id}" do |f| %>
That way our form ID is unique, i.e. annotation_2_feedback and this will also add a prefix, e.g. annotation_2_, to every input created through f.
Did you consider nested_attributes for rails models? Instead of having multiple new feedback forms where each is tied to an annotation, you could have multiple edit annotation forms where each annotation includes fields for a new feedback. The id's of the generated forms would include the annotations id such as edit_annotation_16.
The annotation model would have a relationship to its feedbacks and will also accept nested attributes for them.
class Annotation < ActiveRecord::Base
has_many :feedbacks
accepts_nested_attributes_for :feedbacks
end
class Feedback < ActiveRecord::Base
belongs_to :annotation
end
You could then add as many forms as you want, one for each annotation. For example, this is what I tried:
<% form_for #a do |form| %>
Lyrics: <br />
<%= form.text_field :lyrics %><br />
<% form.fields_for :feedbacks do |feedback| %>
Feedback: <br/>
<%= feedback.text_field :response %><br />
<% end %>
<%= form.submit "Submit" %>
<% end %>
<% form_for #b do |form| %>
Lyrics: <br />
<%= form.text_field :lyrics %><br />
<% form.fields_for :feedbacks do |feedback| %>
Feedback: <br/>
<%= feedback.text_field :response %><br />
<% end %>
<%= form.submit "Submit" %>
<% end %>
And the quick and dirty controller for the above edit view:
class AnnotationsController < ApplicationController
def edit
#a = Annotation.find(1)
#a.feedbacks.build
#b = Annotation.find(2)
#b.feedbacks.build
end
def update
#annotation = Annotation.find(params[:id])
#annotation.update_attributes(params[:annotation])
#annotation.save!
render :index
end
end
I had this same issue on a site I'm currently working on and went with the solution you mention at the bottom. It's not repetitive if you generate the ID programmatically and put the whole form in a partial. For example, on my site, I have multiple "entries" per page, each of which has two voting forms, one to vote up and one to vote down. The record ID for each entry is appended to the DOM ID of its vote forms to make it unique, like so (just shows the vote up button, the vote down button is similar):
<% form_for [entry, Vote.new], :html => { :id => 'new_up_vote_' + entry.id.to_s } do |f| -%>
<%= f.hidden_field :up_vote, :value => 1, :id => 'vote_up_vote_' + entry.id.to_s %>
<%= image_submit_tag('/images/icon_vote_up.png', :id => 'vote_up_vote_submit' + entry.id.to_s, :class => 'vote-button vote-up-button') %>
<% end -%>
I also had the same issue but wanted a more extensible solution than adding the ID to each field. Since we're already using the form_for ... |f| notation the trick is to change the name of the model and you get a new HTML ID prefix.
Using a variant of this method: http://www.dzone.com/snippets/create-classes-runtime (I removed the &block stuff)
I create a new model that is an exact copy of the model I want a second form for on the same page. Then use that new model to render the new form.
If the first form is using
#address = Address.new
then
create_class('AddressNew', Address)
#address_new = AddressNew.new
Your ID prefix will be 'address_new_' instead of 'address_' for the second form of the same model. When you read the form params you can create an Address model to put the values into.
For those stumbling here, looking for the solution for Rails 3.2 app, look at this question instead:
Rails: Using form_for multiple times (DOM ids)

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