Hello Guys, I was doing the course of the PraProg Phoenix LiveView Pro and I was trying to do a validation for the upload files. For example If I try to put just the name of the desks and not put any file for upload, I would like to show the validation for upload a file. I tried to add a validate…

When I arrived in home I was thinking in to inspect the values. So I do this: defmodule LiveViewStudio.Desks.Desk do use Ecto.Schema import Ecto.Changeset schema "desks" do field :name, :string field :photo_urls, {:array, :string}, default: [] timestamps() end @doc false …

I know, in general, the PragProg course doesn’t cast the :photo_urls because you build them explicitly during the live upload process. I’m guessing you want to add extra info for the person’s experience using the upload, in which case you could try some type of logic in your template like: <%= if …

Yes I know in the course it doesn’t cast the :photo_urls. But I was testing to put just the :name and no files for uploads. And then I notice it was saving on the database, but they don’t are showing. So I was trying to do a validate in the schema. For now your help make more sense. But it woul…

I was thinking to try a custom validation(something like this): @doc false def changeset(desk, attrs) do desk |> cast(attrs, [:name, :photo_urls]) |> validate_required([:name]) |> validate_empty_photo_urls(:photo_urls) end def validate_empty_photo_urls(changeset, field) do…

It invokes the validator function to perform the validation only if a change for the given field exists and the change value is not nil. The function must return a list of errors (with an empty list meaning no errors). when the value is nil, the validator function won’t even be called; I believe…

I changed for this: def changeset(desk, attrs) do desk |> cast(attrs, [:name, :photo_urls]) |> validate_empty_photo_urls() |> validate_required([:name]) end def validate_empty_photo_urls(changeset) do photos = get_field(changeset, :photo_urls) if (photos == []) do …

You were on the right track with the previous iteration. The 2nd iteration makes no sense, honestly.

Yes I notice I forget to add the [photo_urls: "must insert a photo!"]. I will stop now because I need to go out. I will try this later. Can you see the other solution I tried? what do you think?

So what I do now for show the error like the error_to_string function? error_to_string(Ecto.ChangeError)?

You started from this: def validate_empty_photo_urls(changeset, field) do validate_change(changeset, field, fn _field, value -> cond do is_nil(value) -> "must insert a photo!" end end) end which was quite close. The docs have this to say: It invokes the validator …

I will try, thank’s for reply @sfusato !

How to validate an array of strings for the upload files in Phoenix LiveView

Questions & Help Questions

PrincetonPoh November 29, 2023, 8:58am 23

So is this working?

Liveview presign_upload() for external uploads triggering even when changeset is NOT valid