Form with nested array of fields without changeset in Phoenix 1.7

Questions & Help Questions
, ,
1

Hello.

I’m working on a system with multiple different widgets in a dashboard. I don’t have widget specific schema, I would like to keep this only using a form definition as there is no need for any validation or complex logic.

But I’m struggling with adding a dynamic rows for a nested form, I can’t get it work with to_form functionality introduced in Phoenix 1.7.

my_form = to_form(%{ 
    "some_key" => "123",
    "properties" => [
      %{ "key" => "some_user_key", "value" => "some_user_value" },
      %{ "key" => "another_user_key", "value" => "another_user_value" }
    ]
  })

And I’m trying to setup the form for the nested properties

I’ve tried something like

<.inputs_for :let={f_nested} field={@my_form[:properties]} default={[]}>
  <.input name="key" field={f_nested[:key] />
  <.input name="value" field={f_nested[:value] />
</.inputs_for>

But this doesn’t work, it works if the properties would be a map, not an array.

I assume I need to iterate over the values, but not use how. Do I need to use inputs_for function instead of the component and iterate over the result?

What is a correct way just using the to_form achieve this? Or do I need to use ecto schemas to achieve this?

Thank you in advance.