What is the correct way to convert HTML to a string for a JSON object in Rails?

Question

JavaScript

There is a view that is designed to respond with JSON to an
AJAX request:

{
  "description": "<%=  @homework.description %>",
  "form_link": "<%= classroom_homework_path(classroom_id, @homework) %>",
  "attachment_ids":  "<%= @homework.attachments.ids.join " " %>",
  "html_id" : "homework<%= @homework.id %>"
  <% if @homework.subject_id %>
    ,"tag": <%= @homework.subject_id %>
  <% end %>
  ,"files": [
    <% first = true %>
    <% @homework.attachments.each do |f| %>

      <% if first %>
        <% first = false %>
      <% else %>
        ,
      <% end %>
      "<%= (render partial: "materials/file", object: f, formats: :html).to_json %>"
    <% end %>
  ]

}

Relevant partial:

<div class="this-material this-material-preview show-X">
  <div class = 'del-this-file'>
    <a class = 'X18' attachment = '<%= file.id%>'>×</a>
  </div>
  <div class="files-image type-document">
  </div>
  <div class="name-files">
    <%= link_to truncate(file.file.file.filename, length: 30), file.file.url %>
  </div>
</div>

This code produces invalid JSON in the HTML render area - double quotes and line wrapping issue.
What is the correct way to solve the problem of rendering HTML to JSON object using Rails?

Answer 1

You need jbuilder (DSL for json generation) or active_model_serializers (implements object approach to json generation)

Answer 2

It is very difficult to parse something, of course. And what should be in the files key, my brain, personally, could not compile in 2 minutes.
Break down the "refactoring", if you can call it that, into the following steps:
1. Throw in the HTML partial
2. Instead of manually collecting text JSON in the view, collect the ruby ​​hash in the controller and call to_json. For example:

def my_action
  res = {
    description: @homework.description,
    ...
    html_id: "homework#{@homework.id}"
  }
  res[:tag] = @homework.subject_id if @homework.subject_id
end

3. Get what res.to_jsonwould give the desired result.
4-a. Read about each_with_index
4-b. Read about Rails Rendering Collections, paragraph 3.4.5
4. Add and make it work:
5. Ideally, shove it all into the model. For example, override Homework's to_json method. The only difference will be that render will need to be called somehow likeActionController::Base.new.render(...)