How to display a value in a template?

Phoenix Forum Questions / Help
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1

Hello! Sorry for the dumb question but how do I display a variable in template. Let’s say I have an input in template and a button for submitting it. Once submitting, the value that I entered in my input passes to a controller. I was able to get the value through the controller and my problem is how do I display it on the same template?

2

do you want to show the value in the template your controller action returns? if so then the you need to pass your value in teh render/3 function, for example:

Given a controller:

defmodule MyAppWeb.MyController do
  use MyAppWeb, :controller


  def new(conn, params = %{"value" => my_value}) do
   # do your stuff
   render(conn, "new.html", value: my_value)
  end

end

render/3 accepts a keyword list or a map as last argument, so anything you need to send to template you put there with a key, so on you template you can access it as

<span><%= @value %></span>

btw, there is no such thing as dumb question! :smile:

3 Likes
3

I gott the error:

assign @value not available in eex template.

4

Do you mind sharing your controller and template code?

2 Likes
5

Most of the times, try restarting mix phx.server.

6

I know this is quite old, but I have this exact same problem, and I’m stuck.

def new(conn, _params) do
      changeset = Administration.change_admin(%Admin{})

      admin_roles = [1,2,3]

      render(conn, "new.html", changeset: changeset, admin_roles: admin_roles)
    end

Then in html <%= admin_roles %>

Error: variable "admin_roles" does not exist
`

UPDATE: realized I need @admin_roles in template

7

I’m trying to pass a “users” variable but I’m receiving the error

KeyError <small>at GET</small> <small>/agendas/new</small>

key :users not found in: %{
  action: "/agendas",
  __changed__: nil,
  __given__: %{
    action: "/agendas",
    __changed__: nil,
    changeset: #Ecto.Changeset<
      action: nil,
      changes: %{},
      errors: [
        data: {"can't be blank", [validation: :required]},
        hora: {"can't be blank", [validation: :required]}
      ],
      data: #Vacinacao.Agendas.Agenda<>,
      valid?: false
    >
  },
  changeset: #Ecto.Changeset<
    action: nil,
    changes: %{},
    errors: [
      data: {"can't be blank", [validation: :required]},
      hora: {"can't be blank", [validation: :required]}
    ],
    data: #Vacinacao.Agendas.Agenda<>,
    valid?: false
  >
}
8

Hello and welcome, please use 3 ` to format your code. I did the change this time.

You don’t show how You try to pass the users to the template. You should, because we don’t know your code