feat: implement custom URLs

Signed-off-by: Amogh Lele <amolele@gmail.com>

lib/ketbin/pastes/paste.ex

@@ -16,5 +16,6 @@ defmodule Ketbin.Pastes.Paste do
     paste
     |> cast(attrs, [:is_url, :content, :id, :belongs_to])
     |> validate_required([:is_url, :content])
+    |> unique_constraint(:id, name: :pastes_pkey)
   end
 end

lib/ketbin_web/controllers/page_controller.ex

@@ -50,8 +50,12 @@ defmodule KetbinWeb.PageController do
   end
 
   def create(%{assigns: %{current_user: current_user}} = conn, %{"paste" => paste_params}) do
-    # generate phonetic key
-    id = Utils.generate_key()
+    # if custom url exists, use it as id, else generate phonetic id
+    id =
+      case Map.get(paste_params, "custom_url", "") do
+        custom_url when custom_url != "" -> custom_url
+        _ -> Utils.generate_key()
+      end
 
     # check if content is a url
     is_url =
@@ -80,9 +84,15 @@ defmodule KetbinWeb.PageController do
 
       # something went wrong, bail
       {:error, %Ecto.Changeset{} = changeset} ->
+        case changeset.errors[:id] do
+          {"has already been taken", _} ->
+            render(conn, "index.html", changeset: changeset, already_taken: true)
+
+          _ ->
             render(conn, "index.html", changeset: changeset)
         end
     end
+  end
 
   def edit(conn, %{"id" => id}) do
     paste = Pastes.get_paste!(id)

lib/ketbin_web/templates/page/edit.html.heex

@@ -1 +1 @@
-<%= render "form.html", Map.put(assigns, :action, Routes.page_path(@conn, :update, @paste)) %>
+<%= render "form.html", Map.put(assigns, :action, Routes.page_path(@conn, :update, @paste)) |> Map.put(:is_edit, true) %>

lib/ketbin_web/templates/page/form.html.heex

@@ -13,9 +13,20 @@
         </div>
     <% end %>
 
+    <%= if assigns[:already_taken] do %>
+        <div class="w-full text-center bg-amber">
+            <p>This custom URL has already been taken.</p>
+        </div>
+    <% end %>
+
     <div class="w-full h-full">
         <%= textarea f, :content, [class: "w-full h-full px-6 py-4 outline-none bg-light-grey font-bold resize-none", placeholder: "> Paste, save, share! (Pasting just a URL will shorten it!)"] %>
         <div class="flex absolute top-0 right-0 p-4">
+            <%= if @current_user && !assigns[:is_edit] do %>
+            <div>
+                <%= text_input f, :custom_url, [class: "px-2 mr-2 outline-none text-black px-2 py-1", placeholder: "Custom URL"]  %>
+            </div>
+            <% end %>
             <button type="submit">
                 <svg
 									class="h-6 w-6 cursor-pointer fill-current text-white hover:text-amber"