I have an Author and Book model. An Author can have many Book, but a Book can only have one Author.
During the creation of a new Author, how do I add a "New Book" button which will add a fields_for for the Author form? I want to be able to add more than one Book. So far, the solution that I have found is just to add a fixed number of fields_for, like this:
<%= form_with(model: author, local: true) do |form| %>
...
<% 5.times do %>
<%= form.fields_for :books do |books| %>
...
<% end %>
<% end %>
...
<% end %>
I do not want it to be like this, what if the author has more than 5 books? I want to be able to add books dynamically. Any solutions?
If you fine with adding a new dependency, there's cacoon gem, which allows you easier handle nested forms.
It's an additional dependency, but the code for adding a new associated record is simple as:
<%= form_for author do |f| %>
...
<%= f.fields_for :books do |book| %>
<%= render 'book_fields', f: book %>
<%= link_to_add_association 'add book', f, :books %>
<%end%>
author.rb
accepts_nested_attributes_for :books,
:allow_destroy => true,
:reject_if => :all_blank
In your view file
<div class="bank_account_details">
<%= f.fields_for :bank_account_details do |builder| %>
<p>
Book: <%= builder.text_field :name %>
<%= builder.check_box :_destroy %>
<%= builder.label :_destroy, "Remove Book" %>
</p>
<% end %>
<div>
<%= link_to_add_fields "Add Book", f ,:books %>
In your controller add parameters
params.require(:author).permit(:name, books_attributes: [:id, :name, :_destroy])
Related
I have fields_for form for update like below:
<%= form_for #cuisine, url: {action: "update" } do |f| %>
<%= f.text_area :name %>
<% #cuisine.ingredients.each do |ing| %>
<%= f.fields_for ing do |ingredient_fields|%>
<%= ingredient_fields.text_area :name, :value=> ing.name %>
<%= ingredient_fields.hidden_field :_destroy%>
<%= link_to_remove_fields 'Remove this ingredient', f %>
<% end %>
<% end %>
<% end %>
my cuisines_controller:
def update
#cuisine = Cuisine.find(params[:id])
if #cuisine.update_attributes(cuisine_params)
redirect_to root_path
else
redirect_to edit_cuisine_path
end
end
Though this shows the form correctly (showing forms filled with #cuisine and its ingredients' info), after reloading the page the #cuisine object gets deleted even when I don't push the submit button.
Any idea what's going on or how to update nested attributes using fields_for?
Thanks in advance.
First you should just use fields_for like this:
<%= f.fields_for :ingredients do |ingredient_fields|%>
<%= ingredient_fields.text_area :name %>
<%= ingredient_fields.hidden_field :_destroy %>
<%= link_to_remove_fields 'Remove this ingredient', f %>
<% end %>
Second you should first check to see if the cuisine_params in your controller permit those attributes:
params.require(:cuisine).permit(:name, ingredients_attributes:[:id, :name, :_destroy])
Lastly, make sure your model has this accepts_nested_attributes_for :ingredients, allow_destroy: true
I have a new action in the marks controller. When the user clicks on 'new marks', I need to display a form which contains list of papers for that student. And each paper has a list of options which the user needs to select.
The association between the models are:
Mark.rb
belongs_to :paper
paper.rb
has_many :options
Option.rb
belongs_to :paper
In the form for #mark, I need to display all the papers and the list of options using 'formtastic'.
I tried doing,
<% #array_papers.each do |paper| %>
<% options = paper.options %>
<%= semantic_form_for paper, url:thinking_marks_path(student_id: #student.id) do |form| %>
<li class="each-question">
<%= form.input :paper, label: "{paper[:name]}" %>
<%= semantic_fields_for :options, paper.object.options do |option| %>
<%= option.input :option, as: :check_boxes %>
<% end %>
</li>
<% end %>
</ul>
<p> <%= link_to 'Save',thinking_marks_path( student_id: #student.id ), :class => 'simple-button course-type' %>
</p>
<% end %>
But it is throwing error:
undefined method `option' for #<Paper:0x0000000fe6d3e0>
What should I do ?
The form variable is the form of paper object.
I advise you to better naming your form variables, eg. paper_form and option_form.
This code should work:
<%= semantic_fields_for :options, paper.object.options do |option_form| %>
<%= option_form.input :option, as: :check_boxes %>
<% end %>
I'm actually trying cocoon gem(by nathanvda) along with simple_form gem to dynamically add and remove fields on a form .I don't understand why the nested form doen't show up on my forms.Here's the code.(I'm newbie of course).Please can I have some help.
menu/_form.html.erb
<%= simple_form_for #menu do |f| %>
<%= f.input :name %>
<%= f.input :price %>
<%= f.simple_fields_for :drinks do |drink| %>
=render "drink_fields", :f => drink.links %>
<%= link_to_add_association "Add drink"%>
<%end%>
<%= f.button :submit %>
<%end%>
menu/_drink_fields.html.erb
.nested-fields
<%= f.input :name %>
<%= link_to_remove_association "remove drink", f %>
these are the models
class Drinks < ActiveRecord::Base
belongs_to :menu
end
class Menu < ActiveRecord::Base
attr_accessible :drinks_attributes
has_many :drinks, :dependent => :destroy
accepts_nested_attributes_for :drinks
end
in assets/javascripts/application.js
//= require cocoon
in layouts/application.html.erb
<%= javascript_include_tag :cocoon %>
Your nested form is wrong, you are mixing haml and erb. If you have no personal preference yet, I would recommend using haml, I find it much easier and cleaner than erb.
All that aside, your menu/_drink_fields.html.erb should look as follows:
<div class='nested-fields'>
<%= f.input :name %>
<%= link_to_remove_association "remove drink", f %>
</div>
Also, inside your menu/_form.html.erb you should write the following:
<%= f.simple_fields_for :drinks do |drink| %>
<%= render "drink_fields", f: drink %>
<% end %>
<%= link_to_add_association "Add drink", f, :drinks %>
Hope this helps.
Thanks for the head ups nathanvda.I finally find a gem to handle nested fields, Here is the link: https://github.com/lailsonbm/awesome_nested_fields.
Update: answered here.
There are lots of good questions and answers here and on the interweb about getting nested_form, collection_select, accepts_nested_attributes_for and fields_for to play nicely together, but I'm still stumped. Thanks in advance if you can help me.
Aim: To generate a new isbn record. An isbn can have many contributors. I am successfully using the ryanb nested_form gem to dynamically produce new contributor fields on a form, as required. One of these fields uses a collection_select drop down of all the name records in Contributor. When the new record is created, the many contributor ids need to be written to the join table (contributors_isbns).
I have got bits of this working, but only to the point where I can save a single contributor ID to the new record in the isbns table. I can't seem to get anywhere in writing any data to the join table.
I have three models. Contributors and Isbns have a many to many relationship, which I've done using has_many :through. An isbn can have many contributors, and a contributor can have many isbns. They are joined via contributors_isbn.
isbn.rb
attr_accessible :contributor_id
has_many :contributors, :through => :contributors_isbns
has_many :contributors_isbns
accepts_nested_attributes_for :contributors
accepts_nested_attributes_for :contributors_isbns
contributor.rb
attr_accessible :isbn_id
has_many :contributors_isbns
has_many :isbns, :through => :contributors_isbns
accepts_nested_attributes_for :isbns
contributors_isbn.rb
class ContributorsIsbn
attr_accessible :isbn_id, :contributor_id
belongs_to :isbn
belongs_to :contributor
accepts_nested_attributes_for :contributors
In the isbns controller:
def new
#isbn = Isbn.new
#title = "Create new ISBN"
1.times {#isbn.contributors.build}
#isbn.contributors_isbns.build.build_contributor
end
(obviously I can't make my mind up on which build method to use.)
In the isbns new.html.erb view:
<%= nested_form_for #isbn, :validate => false do |f| %>
<h1>Create new ISBN</h1>
<%= render 'shared/error_messages', :object => f.object %>
<%= render 'fields', :f => f %>
<div class="actions">
<%= f.submit "Create" %>
</div>
<% end %>
In the _fields partial, a version with a very plain text_field:
<%= field_set_tag 'Contributor' do %>
<%= f.link_to_add "Add Additional Contributor", :contributors %>
<li>
<%= f.label 'Contributor Sequence Number' %>
<%= f.text_field :descriptivedetail_contributor_sequencenumber%>
</li>
<%= f.fields_for :contributors_isbns, :validate => false do |contrib| %>
<li>
<%= contrib.label :id, 'contributors_isbns id' %>
<%= contrib.text_field :id %>
</li>
<% end %>
<li>
<%= f.label 'Contributor Role' %>
<%= f.text_field :descriptivedetail_contributor_contributorrole %>
</li>
<% end %>
And here, a fancier version which doesn't work either:
<%= f.fields_for :contributors_isbns, :validate => false do |contributors| %>
<li>
<%= f.label :personnameinverted, 'Contributor Name' %>
<%= f.collection_select(:contributor_id, Contributor.all, :id, :personnameinverted ) %>
</li>
<% end %>
This code uses the answer from here. Both result in a 'Missing block" error on the nested_form_for #isbn line.
Thanks so much again in advance.
Update: here is some info about the nested_form gem which might come in handy for looking at this sort of problem. And here's a [2009 but still relevant post][4] on accepts_nested_attributes_for.
Update 2: well, here's a thing. I've been poking around on a cut-down version of this in two different models, not using collection_select or has_many through, but just on a simple belongs_to / has_many association. The parent model is Contract and the child model is Istc. I couldn't even create a record through the nested form. However, after looking in the stack and googling the error message "Warning. Can't mass-assign protected attributes" I've just added :istcs_attributes to my :attr_accessible line and now I can add records. A rather crucial bit missing, and a case of RTFM, as it's right there in the gem readme. I'll update later to see if this works on the more complicated has_many through association.
Update 4: [Here][5] is another useful post about how to deal with a nil record error message.
Update 5: Slight detour - When I dynamically added a new set of fields to the form, one one of the child records was being created. Duh - I had the "Add" link inside the child forms area. Here's the before:
<%= f.fields_for :istcs do |istc_form| %>
<h4> Istc</h4>
<%= istc_form.label "istc name" %>
<%= istc_form.text_field :title_title_text %>
<%= istc_form.link_to_remove "[-] Remove this istc"%>
<%= f.link_to_add "[+] Add an istc", :istcs %>
<% end %>
and here's the after:
<%= f.fields_for :istcs do |istc_form| %>
<h4> Istc</h4>
<%= istc_form.label "istc name" %>
<%= istc_form.text_field :title_title_text %>
<%= istc_form.link_to_remove "[-] Remove this istc"%>
<% end %>
<%= f.link_to_add "[+] Add an istc", :istcs %>
Update 6, post-answer:
Oh noes. The collection_select isn't working. It's adding new contributor records, not using an existing one from the contributor model. Someone else had this problem too. Any ideas?
Huzzah! Here's the code which makes all this work. Bit verbose but didn't want to leave anything out. My main learnings:
you need to make the child attributes attr_accessible in the parent model
you need to make the parent and child ids attr_accessible in the join table model
it makes life easier if you build at least one child instance in the parent controller.
contributor.rb model
class Contributor < ActiveRecord::Base
attr_accessible #nothing relevant
has_many :contributors_isbns
has_many :isbns, :through => :contributors_isbns
isbn.rb model
class Isbn < ActiveRecord::Base
attr_accessible :contributors_attributes, :contributor_id, :istc_id #etc
belongs_to :istc
has_many :contributors, :through => :contributors_isbns
has_many :contributors_isbns
accepts_nested_attributes_for :contributors #if you omit this you get a missing block error
contributors_isbn model
class ContributorsIsbn < ActiveRecord::Base
belongs_to :isbn
belongs_to :contributor
attr_accessible :isbn_id, :contributor_id
isbn controller
def new
#isbn = Isbn.new
#title = "Create new ISBN"
1.times {#isbn.contributors.build}
end
new.html.erb
<td class="main">
<%= nested_form_for #isbn, :validate => false do |f| %>
<h1>Create new ISBN</h1>
<%= render 'shared/error_messages', :object => f.object %>
<%= render 'fields', :f => f %>
<div class="actions">
<%= f.submit "Create" %>
</div>
<% end %>
_fields.html.erb
<%= field_set_tag 'Identifier Details' do %>
<li>
<%= f.label 'Title prefix' %>
<%= f.text_field :descriptivedetail_titledetail_titleelement_titleprefix %>
</li>
<li>
<%= f.label 'Title without prefix' %>
<%= f.text_field :descriptivedetail_titledetail_titleelement_titlewithoutprefix %>
</li>
<li>
<%= f.label 'ISTC' %>
<%= f.collection_select(:istc_id, Istc.all, :id, :title_title_text, :prompt => true) %>
</li>
<% end %>
<%= field_set_tag 'Contributor' do %>
<li>
<%= f.label 'Contributor Sequence Number' %>
<%= f.text_field :descriptivedetail_contributor_sequencenumber%>
</li>
<%= f.fields_for :contributors, :validate => false do |contributor_form| %>
<li>
<%= contributor_form.label :personnameinverted, 'Contributor Name' %>
<%= contributor_form.collection_select(:isbn_id, Contributor.all, :id, :personnameinverted ) %>
</li>
<%= contributor_form.link_to_remove "[-] Remove this contributor"%>
<% end %>
<%= f.link_to_add "[+] Add a contributor", :contributors %>
<li>
<%= f.label 'Contributor Role' %>
<%= f.text_field :descriptivedetail_contributor_contributorrole %>
</li>
<% end %>
In my Ruby on Rails application I want to allow the adding/editing of a nested model which itself has an associated model.
model Survey
string title
has_many questions
model Question
string question
belongs_to category
model Category
string name
For the sake of argument let's assume that the user should always have to enter a new category when entering a question (I couldn't come up with a better example, sigh).
In my model/survey/edit.html.erb I have a working setup for adding questions and saving them. However when I added the Category model to the picture, I now face the problem that when adding a new Question, there is no corresponding Category name-field displayed. I suspect this is because even though I do call Question.new, I do not call question.category.build - and I have no idea where/how to do that.
My edit.html.erb:
<h1>Editing Survey</h1>
<%= render :partial => 'form' %>
My _form.html.erb:
<% form_for(#survey) do |f| %>
<%= f.error_messages %>
<p>
<%= f.label :title %><br />
<%= f.text_field :title %>
</p>
<div id="questions">
<% f.fields_for :questions do |q| %>
<%= render :partial => 'question', :locals => { :pf => q } %>
<% end %>
</div>
<%= add_a_new_child_link("New question", f, :questions) %>
<% end %>
My _question.html.erb:
<div class="question">
<%= pf.label :question %>
<%= pf.text_field :question %>
<% pf.fields_for :category do |c| %>
<p>
<%= c.label :name, "Category:" %>
<%= c.text_field :name %>
</p>
<% end %>
</div>
A quick fix for your situation is to use virtual attributes.
EG, in your Question model:
def category_name=(new_name)
if category then
category.name = new_name
else
category = Category.new(:name => new_name)
end
end
def category_name
return category.name if category
""
end
In your _question, there no need to use nested form. Just add something like:
<%= pf.text_field :category_name %>
I didn't test it, but you probably caught the ideea.