I am building a resume builder with the schema

defmodule ModernResume.Resumes.Resume do
  use Ecto.Schema
  import Ecto.Changeset

  @primary_key {:id, :binary_id, autogenerate: true}
  @foreign_key_type :binary_id
  schema "resumes" do
    field :name, :string
    field :email, :string
    field :phone, :string
    field :url, :string
    field :summary, :string

    belongs_to :profile, ModernResume.Profiles.Profile

    has_many :educational_qualifications,
             ModernResume.EducationalQualifications.EducationalQualification,
             preload_order: [desc: :end_date],
             on_replace: :delete

    has_many :work_experiences,
             ModernResume.WorkExperiences.WorkExperience,
             preload_order: [desc: :end_date],
             on_replace: :delete

    has_many :projects,
             ModernResume.Projects.Project,
             on_replace: :delete

    has_many :skills,
             ModernResume.Skills.Skill,
             on_replace: :delete

    timestamps(type: :utc_datetime)
  end

  @doc false
  def changeset(resume, attrs) do
    resume
    |> cast(attrs, [:name, :email, :phone, :url, :summary])
    |> validate_required(:name)
    |> cast_assoc(
      :educational_qualifications,
      with: &ModernResume.EducationalQualifications.EducationalQualification.changeset/2,
      sort_param: :educational_qualifications_order,
      drop_param: :educational_qualifications_delete
    )
    |> cast_assoc(
      :work_experiences,
      with: &ModernResume.WorkExperiences.WorkExperience.changeset/2,
      sort_param: :work_experiences_order,
      drop_param: :work_experiences_delete
    )
    |> cast_assoc(
      :projects,
      with: &ModernResume.Projects.Project.changeset/2,
      sort_param: :projects_order,
      drop_param: :projects_delete
    )
    |> cast_assoc(
      :skills,
      with: &ModernResume.Skills.Skill.changeset/2,
      sort_param: :skills_order,
      drop_param: :skills_delete
    )
  end
end

The Edit LiveView is

defmodule ModernResumeWeb.ResumeLive.Edit do
  use ModernResumeWeb, :live_view

  alias ModernResume.Resumes
  alias ModernResume.TypesettingEngine

  @impl true
  def mount(%{"id" => resume_id}, _session, socket) do
    resume =
      Resumes.get_resume(resume_id)

    changeset =
      Resumes.change_resume(resume)

    {:ok,
     assign(socket,
       resume: resume,
       form: to_form(changeset),
       pdf_base64: nil,
       page_title: resume.name
     )}
  end

  @impl true
  def handle_event("validate", %{"resume" => resume_params}, socket) do
    changeset =
      socket.assigns.resume
      |> Resumes.change_resume(resume_params)
      |> Map.put(:action, :validate)

    {:noreply, assign(socket, form: to_form(changeset))}
  end

  @impl true
  def handle_event("save", %{"resume" => resume_params}, socket) do
    case Resumes.update_resume(
           socket.assigns.resume,
           resume_params
         ) do
      {:ok, resume} ->
        changeset = Resumes.change_resume(resume)

        latex_file_dir =
          TypesettingEngine.to_latex!(resume)
          |> write_latex_file!(resume.id)

        System.cmd("latexmk", ["resume.tex", "-pdf"], cd: latex_file_dir, stderr_to_stdout: true)
        pdf_file_path = Path.join(latex_file_dir, "resume.pdf")
        pdf_base64 = File.read!(pdf_file_path) |> Base.encode64()

        {:noreply,
         assign(socket,
           resume: resume,
           form: to_form(changeset),
           pdf_base64: pdf_base64
         )}

      {:error, changeset} ->
        {:noreply,
         assign(socket,
           form: to_form(changeset)
         )}
    end
  end

  @impl true
  def handle_params(_action, _, socket) do
    header_text =
      if socket.assigns.live_action do
        Phoenix.Naming.humanize(socket.assigns.live_action)
      else
        "Profile"
      end

    {:noreply, socket |> assign(header_text: header_text)}
  end

  def write_latex_file!(content, dirname) do
    tmp_dir = Path.join(System.tmp_dir!(), dirname)
    File.mkdir_p!(tmp_dir)

    tmp_file = Path.join(tmp_dir, "/resume.tex")
    File.write!(tmp_file, content)

    tmp_dir
  end
end

This is the edit.html.heex file

  <div class="min-w-[560px] w-[560px] border-r overflow-y-scroll pb-12">
    <.simple_form id="resume-form" for={@form} phx-submit="save" phx-change="validate">
      <div class="flex flex-row items-center justify-end container-box py-4 border-b">
        <.button class="button-sm">
          <.icon name="hero-document-check" /> Save and Publish
        </.button>
      </div>
      <div class="flex flex-col items-stretch gap-4">
        <div class="container-box flex flex-row items-center justify-between">
          <h2 class="font-medium text-lg text-primary-700"><%= @header_text %></h2>
        </div>
        <div class="form-container container-box py-4 bg-primary-50">
          <.input field={@form[:name]} label="Full name" placeholder="Your name" />
          <.input field={@form[:email]} label="Email" />
          <.input field={@form[:phone]} label="Phone" />
          <.input field={@form[:url]} label="Website / Github / LinkedIn" />
        </div>
      </div>

      <div class="flex flex-col items-stretch gap-4">
        <div class="container-box flex flex-row items-center justify-between">
          <h2 class="font-medium text-lg text-primary-700"><%= @header_text %></h2>
          <label class="button-secondary button-sm">
            <input
              class="hidden"
              type="checkbox"
              name="resume[educational_qualifications_order][]"
            />
            <.icon name="hero-plus-circle" /> Add school
          </label>
        </div>
        <.inputs_for :let={f_eq} field={@form[:educational_qualifications]}>
          <input
            type="hidden"
            name="resume[educational_qualifications_order][]"
            value={f_eq.index}
          />
          <div class="form-container bg-primary-50 container-box py-4">
            <label class="button-outline button-xs self-end">
              <input
                type="checkbox"
                name="resume[educational_qualifications_delete][]"
                value={f_eq.index}
                class="hidden "
              /> <.icon name="hero-x-mark" /> Remove school
            </label>
            <.input field={f_eq[:institution]} label="Institution" placeholder="Your school name" />
            <.input field={f_eq[:location]} label="Location" />
            <.input field={f_eq[:degree]} label="Degree" />
            <.input field={f_eq[:major]} label="Major" />
            <.input field={f_eq[:score]} label="Score / GPA" />
            <div class="flex flex-row gap-4">
              <div>
                <.input type="date" field={f_eq[:start_date]} label="Start date" />
              </div>
              <div>
                <.input
                  type="date"
                  field={f_eq[:end_date]}
                  label="End date (empty if currently studying)"
                />
              </div>
            </div>
          </div>
        </.inputs_for>
      </div>

      <div :if={@live_action == :work_experiences} class="flex flex-col items-stretch gap-4">
        <div class="container-box flex flex-row items-center justify-between">
          <h2 class="font-medium text-lg text-primary-700"><%= @header_text %></h2>
          <label class="button-secondary button-sm">
            <input class="hidden" type="checkbox" name="resume[work_experiences_order][]" />
            <.icon name="hero-plus-circle" /> Add company
          </label>
        </div>
        <.inputs_for :let={f_we} field={@form[:work_experiences]}>
          <input type="hidden" name="resume[work_experiences_order][]" value={f_we.index} />
          <div class="form-container bg-primary-50 container-box py-4">
            <label class="button-outline button-xs self-end">
              <input
                type="checkbox"
                name="resume[work_experiences_delete][]"
                value={f_we.index}
                class="hidden "
              /> <.icon name="hero-x-mark" /> Remove company
            </label>
            <.input field={f_we[:name]} label="Company name" placeholder="Your company name" />
            <.input field={f_we[:location]} label="Location" />
            <.input field={f_we[:position]} label="Position" />
            <.input field={f_we[:url]} label="Company Website" />

            <div class="flex flex-row gap-4">
              <div>
                <.input type="date" field={f_we[:start_date]} label="Start date" />
              </div>
              <div>
                <.input
                  type="date"
                  field={f_we[:end_date]}
                  label="End date (empty if currently working)"
                />
              </div>
            </div>
            <div>
              <div class="mt-8 flex flex-row items-center justify-between mb-2">
                <h3 class="font-medium">Highlights</h3>
                <label class="button-secondary button-xs">
                  <input
                    type="checkbox"
                    class="hidden"
                    name={"resume[work_experiences][#{f_we.index}][highlights_order][]"}
                  />
                  <.icon name="hero-plus-circle" /> Add highlight
                </label>
              </div>
              <.inputs_for :let={f_we_h} field={f_we[:highlights]}>
                <div class="py-4">
                  <div class="flex flex-row justify-end"></div>
                  <input
                    type="hidden"
                    name={"resume[work_experiences][#{f_we.index}][highlights_order][]"}
                    value={f_we_h.index}
                  />
                  <div class="flex flex-row items-start gap-2">
                    <.input field={f_we_h[:description]} />
                    <label class="button-outline button-xs h-10 gap-1">
                      <input
                        type="checkbox"
                        name={"resume[work_experiences][#{f_we.index}][highlights_delete][]"}
                        value={f_we_h.index}
                        class="hidden"
                      /> <.icon name="hero-x-mark" />
                    </label>
                  </div>
                </div>
              </.inputs_for>
            </div>
          </div>
        </.inputs_for>
      </div>

      <div :if={@live_action == :projects} class="flex flex-col items-stretch gap-4">
        <div class="container-box flex flex-row items-center justify-between">
          <h2 class="font-medium text-lg text-primary-700"><%= @header_text %></h2>
          <label class="button-secondary button-sm">
            <input type="checkbox" name="resume[projects_order][]" class="hidden" />
            <.icon name="hero-plus-circle" /> Add project
          </label>
        </div>
        <.inputs_for :let={f_p} field={@form[:projects]}>
          <input type="hidden" name="resume[projects_order][]" value={f_p.index} />
          <div class="form-container bg-primary-50 container-box py-4">
            <label class="button-outline button-xs self-end">
              <input
                type="checkbox"
                name="resume[projects_delete][]"
                value={f_p.index}
                class="hidden"
              /> <.icon name="hero-x-mark" /> Remove project
            </label>
            <.input field={f_p[:name]} label="Name" />
            <.input field={f_p[:description]} label="Description" />
            <.input field={f_p[:url]} label="Link" />
          </div>
        </.inputs_for>
      </div>

      <div :if={@live_action == :skills} class="flex flex-col items-stretch gap-4">
        <div class="container-box flex flex-row items-center justify-between">
          <h2 class="font-medium text-lg text-primary-700"><%= @header_text %></h2>
          <label class="button-secondary button-sm">
            <input type="checkbox" name="resume[skills_order][]" class="hidden" />
            <.icon name="hero-plus-circle" /> Add skill
          </label>
        </div>
        <.inputs_for :let={f_s} field={@form[:skills]}>
          <input type="hidden" name="resume[skills_order][]" value={f_s.index} />
          <div class="form-container bg-primary-50 container-box py-4">
            <label class="button-outline button-xs self-end">
              <input
                type="checkbox"
                name="resume[skills_delete][]"
                value={f_s.index}
                class="hidden"
              /> <.icon name="hero-x-mark" /> Remove skill
            </label>
            <.input field={f_s[:name]} label="Name" />
            <.input field={f_s[:description]} label="Description" />
          </div>
        </.inputs_for>
      </div>

      <:actions></:actions>
    </.simple_form>
  </div>

I’m using the new sort_param and drop_param introduced in the latest ecto update. The issue is everything else works fine, but when I delete the last element of the educational_qualification or work_experience the form gets reset with the association still there. I can add and remove association until it’s the last association.

Here is a video recording https://www.youtube.com/watch?v=8ZqXnKPb0Ac

The validate function processes the changeset correctly, but once the save event is invoked an empty %{} is sent params. The delete params are missing. Any help would be greatly appreciated.