Can I build several objects in different parts of a page? - ruby-on-rails

Question

I have a Page model that has many TextBlock:
class Page < ApplicationRecord
has_many :text_blocks, as: :textable, dependent: :destroy
accepts_nested_attributes_for :text_blocks
end
In the form where a page can be edited, I have to display 3 text blocks in the upper part of the form, and 3 text blocks in the lower part of the form. Here is the code in my view...
Upper text blocks:
<%= render 'shared/admin/form-fields/text-blocks-form', f: f, number: 3, value: true %>
Lower text blocks:
<%= render 'shared/admin/form-fields/text-blocks-form', f: f, number: 2, value: false %>
And here is the text-blocks-form partial:
<div class="form-group">
<div class="row">
<div class="col-lg-12 text-blocks">
<div class="row">
<% number.times { f.object.text_blocks.where(upper_position: value).build } unless f.object.text_blocks.where(upper_position: value).any? %>
<%= f.fields_for :text_blocks do |input| %>
<div class="<%= "col-lg-#{cells(number)}" %>">
<%= render 'shared/admin/form-fields/text-blocks-fields', f: input, value: value %>
</div>
<% end %>
</div>
</div>
</div>
</div>
Upper text blocks are built as expected, there are 3 blocks but in the lower part of the form, there are 5 blocks instead of 2. It seems, that it just add 3 + 2. Is there any way to build text blocks as it was described above? Thanks ahead.

Answer 1

I can easily explain why you have this problem, maybe a little less easy to fix this in good way.
The reason why have this that in the first run you create three nested items (on the association), and then iterate over them using f.fields_for :text_blocks, and in the second run you add two more, and then iterating over f.fields_for :text_blocks will iterate over all five created blocks.
An easy fix would be to change your view as follows:
<div class="form-group">
<div class="row">
<div class="col-lg-12 text-blocks">
<div class="row">
<% number.times { f.object.text_blocks.where(upper_position: value).build } unless f.object.text_blocks.where(upper_position: value).any? %>
<%= f.fields_for :text_blocks do |input| %>
<%- if input.object.upper_position == value %>
<div class="<%= "col-lg-#{cells(number)}" %>">
<%= render 'shared/admin/form-fields/text-blocks-fields', f: input, value: value %>
</div>
<% end %>
<% end %>
</div>
</div>
</div>
</div>
If you always have 5 blocks (3 on top and 2 below), I would also consider adding a position or order column, allowing the textblocks to be re-rendered in the correct position after save as well.