Rails：链接到外部属性URL

Question

I'm new on Ror, I created a meetings index page, on my app, where it is possible to book a seat for a meeting. I would like to create for each meeting on this page, a button which redirects in target_blank to an external url. The external url is a string attribute (reservation) of my table. I don't find how to realize this feature. Thk in advance for your help. Here is my code:

schema.db:

 create_table "meetings", force: :cascade do |t|
    t.string "name"
    t.datetime "start_time"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
    t.bigint "user_id"
    t.string "details"
    t.string "address"
    t.boolean "highlight"
    t.string "reservation"
    t.string "participation"
    t.index ["user_id"], name: "index_meetings_on_user_id"
  end

meetings.html.erb:

<% @meetings.each do |meeting| %>
  <strong><%= meeting.name %></strong>
  <br><%= meeting.details %><hr>
  <% if user_signed_in? %>
  <%= link_to "Book a seat", ??????, :target => "_blank" %>
<% end %>
<% end %>

meetings/_form.html.erb:

<%= simple_form_for(@meeting) do |f| %>
<div class="form-inputs">
<%= f.input :name %>
<%= f.input :start_time %>
<%= f.input :details %>
<%= f.input :address %>
<%= f.input :reservation %>
<%= f.input :participation %>
<%= f.check_box :highlight %> Mettre en avant cet évènement
</div>
<div class="form-actions">
<%= f.button :submit %>
</div>

Answer 1

您可以像这样将URL传递给link_to帮助器：

<%= link_to "Book a seat", meeting.reservation, :target => "_blank" %>

Answer 2

For external links, you need a link with http (for example: http://stackoverflow.com ):

<%= link_to "your label", "your link with http", :target => "_blank" %>

So it should be

<%= link_to "Book a seat", meeting.reservation, :target => "_blank" %>

This will create a link that opens in a new tab.

If you are not sure about your links starting with http you can use:

<%= link_to "Book a seat", meeting.reservation.starts_with?('http') ? meeting.reservation : "http://#{meeting.reservation}", :target => "_blank" %>