accessing related record attributes in nested form - ruby-on-rails

In a nested form, that is only used for updates
<%= form_for(#event) do |f| %>
<%= f.fields_for :distances do |distance| %>
<%= distance.check_box :active %>
the form functions in updating the child record. However I cannot call any attirbute of the related record with either for distanceprefix
<%= distance.starting_point %>
How can this value be rendered?

Try like this, it create new object only if not present:
<%= form_for(#event) do |f| %>
<%= f.fields_for :distances, f.object.distances || f.object.build_distances do |distance| %>
<%= distance.check_box :active %>
<%= distance.starting_point %>

<%= distance.object.starting_point %>
renders the child attribute

Related

Rails undefined method form fields_for

I am trying to add dynamic fields to my rails application.
I have a fields_for
<%= form.fields_for :books do |book| %>
<%= render 'book_fields', form: book %>
<% end %>
<%= link_to_add_fields "Add Field", form, :books %>
When it renders book_fields I am getting the following error
If I am passing form in render why would I be getting this error?
I have tried book.label :title but I get the same error but instead of the undefined varaible being form it is book. Any ideas? Thanks in advance.
UPDATE:
<%= form.fields_for :books do |builder| %>
<%= form.label :title %>
<%= form.text_field :title %>
<%= form.hidden_field :_destroy %>
<% end %>
If I remove the partial render and stick the form text fields and labels into the fields_for itself it works. While rendering the partial, that is when I get the error.
Instead using the form block variable as the local in your render method, you have to use the builder one, like:
<%= form.fields_for :books do |book| %>
<%= render 'book_fields', f: book %>
<% end %>
In the partial:
<fieldset>
<%= f.label :title %>
</fieldset>
The error is happening because you're using your "main" form variable, and when the partial is being load, Rails try to find it as a local variable, which doesn't exist in that context.

Displaying hstore saved values in form for input when editing

I got a problem with displaying saved values in form_for for hstore data (filters).
It's saved in database but when I'm going back to this view to edit something I can't see actual values in input form fields like in normal form_for without hashes.
This is shorcut of me view code
<%= form_for #lesson, url: { action: "step3" } do |f| %>
<%= f.fields_for :filters do |d| %>
<%= #lesson.filters["age_from"] %> # like this value would be displayed
<%= d.text_field :age_from %>
<%= d.text_field :age_to %>
<%= d.text_field :name %>
<%= link_to "Back", step1_lesson_path(#lesson) %>
<%= submit_tag "Next" %>
<%end%>
<%end%>
Thanks in advence
Can you try with changing the view a bit, passing #lesson.filters in fields_for as following
....
<%= f.fields_for :filters, OpenStruct.new(#lesson.filters) do |d| %>
#your code goes here ...
<% end %>
....
Solution without modifying controller action:
<%= f.fields_for :filters, OpenStruct.new(#lesson.filters) do |d| %>

With simple_form, how to group multiple inputs and still have correct validation error handling

I often have the situation where I need multiple form elements to appear at one place. For instance:
<%= simple_form_for #user do |f| %>
<%= f.input :active_from do %>
<%= f.input_field :active_from %>
to
<%= f.input_field :active_to %>
<% end %>
<% end %>
This is how I do it at the moment. But there are two problems I have with this solution:
For the wrapping input, which field name to pass? In this example, I just took the first
one, but acutally I'd like to pass both (i.e. f.input [:active_from, :active_to] do). However, this is more of a cosmetical thing if problem 2) can be solved otherwise.
Say, both of these fields are required, how to get error messages for both of these? Somehow, the parent element needs to know that at least one of the sub-inputs has an error and there must be some way of displaying messages. Maybe something like that:
<%= simple_form_for #user do |f| %>
<%= f.input :active_from do %>
<%= f.input_field :active_from %>
<%= f.errors_for :active_from %>
to
<%= f.input_field :active_to %>
<%= f.errors_for :active_to %>
<% end %>
<% end %>

How to submit multiple, duplicate forms from same page in Rails - preferably with one button

In my new views page I have:
<% 10.times do %>
<%= render 'group_member_form' %>
<% end %>
Now this form contains the fields: first_name, last_name, email_address and mobile_number. Basically I want to be able to fill in the fields of all the forms in one click which then submits each into the database as a unique row/id.
What would be the easiest way to accomplish this?
Note: The number of times do is called from a variable. Any advice welcome, thanks!
You should have only one form (you should put only fields in the group_member_form partial). In your view you should have something like:
<%= form_tag "/members" do %>
<% 10.times do %>
<%= render 'group_member_form' %>
<% end %>
<%= submit_tag "Submit" %>
<% end %>
and in _group_member_form.html.erb you should have
<%= text_field_tag "members[][first_name]" %>
<%= text_field_tag "members[][last_name]" %>
<%= text_field_tag "members[][email_address]" %>
<%= text_field_tag "members[][mobile_number]" %>
This way, when the form submits, params[:members] in the controller will be an array of member hashes. So, for example, to get the email adress from the fourth member after submitting the form, you call params[:members][3][:email_adress].
To understand why I wrote _group_member_form.html.erb like this, take a glance at this:
http://guides.rubyonrails.org/form_helpers.html#understanding-parameter-naming-conventions.
You can also use accepts_nested_attributes_for in your model, and use fields_for on your form.
Submitting multiple forms, afaik, only javascript, if the forms are remote: true, and you run through each of them and then submit.
$("form.class_of_forms").each(function() {
$(this).submit();
});
Alternatively a more up to date approach using form_with and fields_for, without removing the form into a partial, could be written like this:
<%= form_with (url: end_point_path), remote: true do |form| %>
<% (1..5).each do |i| %>
<%= fields_for 'cart_items'+[i].to_s do |fields|%>
<%= fields.text_field :first_name %>
<%= fields.text_field :last_name %>
<%= fields.email_field :email_address %>
<%= fields.number_field :phone_number %>
<% end %>
<% end %>
<%= form.submit "Submit" %>
<% end %>

Rails Nested Attributes Doesn't Insert ID Correctly

I'm attempting to edit a model's nested attributes, much as outline here, replicated here:
<%= form_for #person do |person_form| %>
<%= person_form.text_field :name %>
<% for address in #person.addresses %>
<%= person_form.fields_for address, :index => address do |address_form|%>
<%= address_form.text_field :city %>
<% end %>
<% end %>
<% end %>
In my code, I have the following:
<%= form_for(#meal) do |f| %>
<!-- some other stuff that's irrelevant... -->
<% for subitem in #meal.meal_line_items %>
<!-- # Edit 2: I need to display information here about the subitem
Which I can't find a way to pass it to the partial, or work in
this manner for existing items
-->
<%= subitem.food.name %>
<%= subitem.food.calories %>
<%= f.fields_for subitem, :index => subitem do |line_item_form| %>
<%= line_item_form.label :servings %><br/>
<%= line_item_form.text_field :servings %><br/>
<%= line_item_form.label :food_id %><br/>
<%= line_item_form.text_field :food_id %><br/>
<% end %>
<% end %>
<%= f.submit %>
<% end %>
This works great, except, when I look at the HTML, it's creating the inputs that look like the following, failing to input the correct id and instead placing the memory representation(?) of the model. As a result, an update fails:
<input type="text" value="2" size="30" name="meal[meal_line_item][#<MealLineItem:0x00000005c5d618>][servings]" id="meal_meal_line_item_#<MealLineItem:0x00000005c5d618>_servings">
EDIT:
The reason I'm attempting to do it in this method is that I need to gather some information on associations for existing meal_line_items. For example, in the area where I took out code, I have some code to the effect of:
<%= subitem.food.name %>
<%= subitem.food.calories %>
Getting this information won't work if I am using a form builder with partials, at least, not in my trials.
Edit 2:*
See the edit in the code. Here's my MealLineItem
class MealLineItem < ActiveRecord::Base
# Associations ---------------------
belongs_to :food
belongs_to :meal
end
And meal accepts_nested_attributes for the model. As you can see it belongs to both food and meal model. For the existing meal_line_item I need to do something like:
meal_line_item.food.name
Is there f. missing from <%= fields_for?
--edit
Have you tried:
<%= f.fields_for 'meal[meal_line_item][]', subitem do |line_item_form| %>
--edit
Docs say that it should work without loop too:
<%= form_for(#meal) do |f| %>
<!-- some other stuff that's irrelevant... -->
<%= f.fields_for :meal_line_items do |line_item_form| %>
<%= line_item_form.label :servings %><br/>
<%= line_item_form.text_field :servings %><br/>
<%= line_item_form.label :food_id %><br/>
<%= line_item_form.text_field :food_id %><br/>
<% end %>
<%= f.submit %>
<% end %>
Have to test this but maybe this approach?
_form
<%= form.fields_for :meal_line_items do |meal_line_item_form| %>
<% #meal.meal_line_items.each do |meal_line_item| %>
<%= render :partial => "meal_line_items/meal_line_item", :locals => { :meal_line_item_form => meal_line_item_form, :meal_line_item => meal_line_item } %>
<% end %>
<% end %>
meal_line_items/_meal_line_item.erb
<%= meal_line_item_form.label :servings %><br/>
<%= meal_line_item_form.text_field :servings %><br/>
<%= meal_line_item_form.label :food_id %><br/>
<%= meal_line_item_form.text_field :food_id %><br/>
EDIT
here's a link to an example for setting the formbuilder iterator directly (Rails 2.3.8 though). The associations between Outbreak -> Incidents -> Location should be similiar to the ones for Meal -> Meal_line_items -> Food.
AJAX update of accepts_nested_attributes_for partials
After searching high and low, I found the error. Although I was modifying the partial and was receiving a NameError it's because I was calling the partial from a helper method - exactly the same problem as stated in the following question:
rails fields_for render partial with multiple locals producing undefined variable

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