Issue with cast_assoc for nested has_many assoc

Phoenix Forum Questions / Help
1

please i would like to understand how to implement cast_assoc form for has many relationship using inputs_for for the nested relationship but currently only working for has_one and not implementing for has_many relatiosnhip, when it comes to has many only the main field showing not the associated field:

Screenshot (69)
Screenshot (69)1200×675 38.9 KB

This is the html aspect of my code:

  <%= form_for @payment_changeset, "#", [phx_submit: :create_payment, phx_change: :validate_payment_entry, phx_target: @myself, id: "capture_account_info"], fn f -> %>
          <div class="border border-gray-300 rounded-lg p-6 bg-white shadow-md">
            <div class="manual-entry-css">
              <div class="flex md:flex-row flex-col items-center justify-between gap-4">
                <%= inputs_for f, :beneficiaries, fn b_changeset -> %>
                  <div class="py-3">
                    <%= select(
                      b_changeset,
                      :bank_id,
                      Enum.map(@bank_names, &{&1.bank_name, &1.id}),
                      required: true,
                      class: "focus:outline-0 px-4 py-2 rounded-l-md w-full border form-control",
                      phx_update: :ignore
                    ) %>
                    <%= hidden_input(b_changeset, :bank_location, value: "local") %>
                  </div>

                  <div class="py-3">
                    <%= text_input(b_changeset, :account_number,
                      required: true,
                      class: "w-full form-control",
                      placeholder: " Account Number"
                    ) %>
                    <p class="block ">
                      <%= error_tag(b_changeset, :account_number) %>
                    </p>
                  </div>
                <% end %>
                <div class="py-3">
                  <%= text_input(
                    f,
                    :balance,
                    class: "w-full form-control",
                    placeholder: "Amount",
                    required: true
                  ) %>
                </div>
              </div>
            </div>
            <div class="flex items-end justify-end lg:mt-2 mt-4">
              <button phx-target={@myself} type="submit" class="btn-primary rounded-sm">
                Add
              </button>
            </div>
          </div>
        <% end %>
      </div>
    <% end %>

please i need help with fixing this problem

2

Please am stll facing the issue

3

Hi @bennydreamtech23 can you provide more information? What is the main schema you are operating with? What is the has_many relationship you want to create? What have you tried so far?

2 Likes
4

i have done the relationship in the schema aspect but when implemented in the form only the has_one relationship is working.
these is the schema for payments that has many beneficiary:

 schema "payments" do
    field(:tax, :float)
    field(:balance, :float)
    field(:currency, :string)
    field(:status, :string)
    belongs_to(:wallet, Data.Schema.UserWallet)
    belongs_to(:sender, UserDb)
    belongs_to(:payment_receiver, Data.Schema.PaymentReceiver)
    has_many(:beneficiaries, Data.Schema.Beneficiary)
    timestamps()
  end.

currently using this changeset from payment to do validation and form submission

def payment_changeset(payment, attrs) do
    payment
    |> cast(attrs, @payment_fields)
    |> cast_assoc(:beneficiaries,
      with: &Beneficiary.changeset_with_account_number_length_validation/2,
      required: true
    )
    |> validate_required(@payment_fields)
  end

these is the schema for the beneficiaries

 schema "beneficiaries" do
    field(:recipient_country, :string)
    field(:bank_location, :string)
    field(:currency, :string)
    field(:bank_name, :string)
    field(:account_name, :string)
    field(:account_number, :string)
    field(:is_deleted, :boolean, default: false)
    belongs_to(:user, UserDb)
    belongs_to(:bank, Bank, foreign_key: :bank_id)
    belongs_to(:payment, Payment, foreign_key: :payment_id)
    timestamps()
  end

currenlty using this changeset for the beneficiary

  def changeset_with_account_number_length_validation(beneficiary, attrs) do
    changeset(beneficiary, attrs)
    |> validate_account_number_length()
  end.

but when i use all these in the form it return all the balance which is a column in the schema of payments in the ui aspect and other attributes related to beneficiary dont work, for the has many relationship but when it comes to has_ one the whole schema for both is shown

5

Do your payments already have pre-existing beneficiaries? If so, when you are fetching the payment from the database, are you preloading the beneficiaries?

6

nope, payment dont have pre existing beneficiaries, they both seperate tables

7

One thing different moving from has_one to has_many is that inputs_for won’t render any inputs if there’s no items unless you tell it to add ones. You might be running into that case.

8

so how can solve the issue of creating one item and adding more using input for, or is there a way to use the beneficiaries schema and validate it without using it changeset. like using map.merge

9

Multiple options. I’d suggest the first one, unless that doesn’t work for some reason in your usecase:

The second one can still be educational nontheless.

1 Like
10

Thank you, i will check them out and give feedback once i am done

1 Like