Composite Primary Keys (WIP)

lib/kaffy/resource_admin.ex

@@ -2,6 +2,8 @@ defmodule Kaffy.ResourceAdmin do
   alias Kaffy.ResourceSchema
   alias Kaffy.Utils
 
+  @default_id_separator "."
+
   @moduledoc """
   ResourceAdmin modules should be created for every schema you want to customize/configure in Kaffy.
 
@@ -119,7 +121,7 @@ defmodule Kaffy.ResourceAdmin do
   @doc """
   `ordering/1` takes a schema and returns how the entries should be ordered.
 
-  If `ordering/1` is not defined, Kaffy will return `[desc: :id]`.
+  If `ordering/1` is not defined, Kaffy will return `[desc: primary_key]`, or the first field of the primary key, if it's a composite.
 
   Example:
 
@@ -130,7 +132,10 @@ defmodule Kaffy.ResourceAdmin do
   ```
   """
   def ordering(resource) do
-    Utils.get_assigned_value_or_default(resource, :ordering, desc: :id)
+    schema = resource[:schema]
+    [order_key | _] = ResourceSchema.primary_keys(schema)
+
+    Utils.get_assigned_value_or_default(resource, :ordering, desc: order_key)
   end
 
   @doc """
@@ -293,6 +298,52 @@ defmodule Kaffy.ResourceAdmin do
     Utils.get_assigned_value_or_default(resource, :plural_name, default)
   end
 
+  @doc """
+  `serialize_id/2` takes a schema and record and must return a string to be used in the URL and form values.
+
+  If `serialize_id/2` is not defined, Kaffy will concatenate multiple primary keys with `"."` as a separator.
+
+  Example:
+
+  ```elixir
+  def serialize_id(_schema, record) do
+    Enum.join([record.post_id, record.tag_id], ".")
+  end
+  ```
+  """
+  def serialize_id(resource, entry) do
+    schema = resource[:schema]
+    default = schema
+      |> ResourceSchema.primary_keys()
+      |> Enum.map_join(@default_id_separator, &Map.get(entry, &1))
+
+    Utils.get_assigned_value_or_default(resource, :serialize_id, default, [entry])
+  end
+
+  @doc """
+  `deserialize_id/2` takes a schema and serialized id and must return a complete
+  keyword list in the form of [{:primary_key, value}, ...].
+
+  If `deserialize_id/2` is not defined, Kaffy will split multiple primary keys with `"."` as a separator.
+
+  Example:
+
+  ```elixir
+  def serialize_id(_schema, serialized_id) do
+    Enum.zip([:post_id, :tag_id], String.split(serialized_id, "."))
+  end
+  ```
+  """
+  def deserialize_id(resource, id) do
+    schema = resource[:schema]
+    id_list = String.split(id, @default_id_separator)
+    default = schema
+      |> ResourceSchema.primary_keys()
+      |> Enum.zip(id_list)
+
+    Utils.get_assigned_value_or_default(resource, :deserialize_id, default, [id])
+  end
+
   def resource_actions(resource, conn) do
     Utils.get_assigned_value_or_default(resource, :resource_actions, nil, [conn], false)
   end

lib/kaffy/resource_form.ex

@@ -49,8 +49,14 @@ defmodule Kaffy.ResourceForm do
         opts
       end
 
+    # Check if any primary key fields are nil
+    is_create_event = changeset.data.__struct__
+      |> Kaffy.ResourceSchema.primary_keys()
+      |> Enum.map(&Map.get(changeset.data, &1))
+      |> Enum.any?(&is_nil/1)
+
     permission =
-      case is_nil(changeset.data.id) do
+      case is_create_event do
         true -> Map.get(options, :create, :editable)
         false -> Map.get(options, :update, :editable)
       end
@@ -102,13 +108,13 @@ defmodule Kaffy.ResourceForm do
         end)
 
       :id ->
-        case Kaffy.ResourceSchema.primary_key(schema) == [field] do
+        case field in Kaffy.ResourceSchema.primary_keys(schema) do
           true -> text_input(form, field, opts)
           false -> text_or_assoc(conn, schema, form, field, opts)
         end
 
       :binary_id ->
-        case Kaffy.ResourceSchema.primary_key(schema) == [field] do
+        case field in Kaffy.ResourceSchema.primary_keys(schema) do
           true -> text_input(form, field, opts)
           false -> text_or_assoc(conn, schema, form, field, opts)
         end

lib/kaffy/resource_query.ex

@@ -46,7 +46,8 @@ defmodule Kaffy.ResourceQuery do
 
   def fetch_resource(conn, resource, id) do
     schema = resource[:schema]
-    query = from(s in schema, where: s.id == ^id)
+    id_filter = Kaffy.ResourceAdmin.deserialize_id(resource, id)
+    query = from(s in schema, where: ^id_filter)
     custom_query = Kaffy.ResourceAdmin.custom_show_query(conn, resource, query)
     Kaffy.Utils.repo().one(custom_query)
   end

lib/kaffy/resource_schema.ex

@@ -1,7 +1,7 @@
 defmodule Kaffy.ResourceSchema do
   @moduledoc false
 
-  def primary_key(schema) do
+  def primary_keys(schema) do
     schema.__schema__(:primary_key)
   end
 
@@ -24,7 +24,10 @@ defmodule Kaffy.ResourceSchema do
   end
 
   def form_fields(schema) do
-    to_be_removed = fields_to_be_removed(schema) ++ [:id, :inserted_at, :updated_at]
+    to_be_removed =
+      fields_to_be_removed(schema) ++
+        primary_keys(schema) ++
+        [:inserted_at, :updated_at]
     Keyword.drop(fields(schema), to_be_removed)
   end
 
@@ -33,7 +36,9 @@ defmodule Kaffy.ResourceSchema do
       fields_to_be_removed(schema) ++
         get_has_many_associations(schema) ++
         get_has_one_assocations(schema) ++
-        get_many_to_many_associations(schema) ++ [:id, :inserted_at, :updated_at]
+        get_many_to_many_associations(schema) ++
+        primary_keys(schema) ++
+        [:inserted_at, :updated_at]
 
     Keyword.drop(fields(schema), to_be_removed)
   end

lib/kaffy_web/controllers/resource_controller.ex

@@ -383,14 +383,16 @@ defmodule KaffyWeb.ResourceController do
   end
 
   defp redirect_to_resource(conn, context, resource, entry) do
+    id = Kaffy.ResourceAdmin.serialize_id(resource, entry)
+
     redirect(conn,
       to:
         Kaffy.Utils.router().kaffy_resource_path(
           conn,
           :show,
           context,
           resource,
-          entry.id
+          id
         )
     )
   end

lib/kaffy_web/templates/resource/_table.html.eex

@@ -4,17 +4,17 @@
     </thead>
 
     <tbody>
-        <%= for entry <- @entries do %>
+        <%= for {entry, index} <- Enum.with_index(@entries) do %>
             <tr>
                 <td>
                     <div class="custom-control custom-checkbox">
-                        <input type="checkbox" class="custom-control-input select-item kaffy-resource-checkbox" id="kaffy-select-<%= entry.id %>" name="resource" value="<%= entry.id %>"/>
-                        <label class="custom-control-label" for="kaffy-select-<%= entry.id %>"></label>
+                        <input type="checkbox" class="custom-control-input select-item kaffy-resource-checkbox" id="kaffy-select-<%= index %>" name="resource" value="<%= Kaffy.ResourceAdmin.serialize_id(@my_resource, entry) %>"/>
+                        <label class="custom-control-label" for="kaffy-select-<%= index %>"></label>
                     </div>
                 </td>
                 <%= for {field, index} <- Enum.with_index(@fields) do %>
                     <%= if index == 0 do %>
-                        <td><%= link Kaffy.ResourceSchema.kaffy_field_value(@conn, entry, field), to: Kaffy.Utils.router().kaffy_resource_path(@conn, :show, @context, @resource, entry) %></td>
+                        <td><%= link Kaffy.ResourceSchema.kaffy_field_value(@conn, entry, field), to: Kaffy.Utils.router().kaffy_resource_path(@conn, :show, @context, @resource, Kaffy.ResourceAdmin.serialize_id(@my_resource, entry)) %></td>
                     <% else %>
                         <td><%= Kaffy.ResourceSchema.kaffy_field_value(@conn, entry, field) %></td>
                     <% end %>

lib/kaffy_web/templates/resource/show.html.eex

@@ -9,7 +9,7 @@
         <div class="card-header">
             <div class="row justify-content-between">
                 <div class="col-auto mr-auto">
-                    <h1><%= @resource_name %> #<%= @changeset.data.id %></h1>
+                    <h1><%= @resource_name %> #<%= Kaffy.ResourceAdmin.serialize_id(@my_resource, @changeset.data) %></h1>
                 </div>
                 <div class="col-auto">
                     <%= if Kaffy.ResourceAdmin.resource_actions(@my_resource, @conn) do %>
@@ -20,7 +20,7 @@
                                 </button>
                                 <div class="dropdown-menu">
                                     <%= for {action_key, options} <- Kaffy.ResourceAdmin.resource_actions(@my_resource, @conn) do %>
-                                        <%= form_tag(Kaffy.Utils.router().kaffy_resource_path(@conn, :single_action, @context, @resource, @changeset.data.id, to_string(action_key)), method: :post) %>
+                                        <%= form_tag(Kaffy.Utils.router().kaffy_resource_path(@conn, :single_action, @context, @resource, Kaffy.ResourceAdmin.serialize_id(@my_resource, @changeset.data), to_string(action_key)), method: :post) %>
                                             <input type="submit" name="submit" value="<%= options.name %>" class="dropdown-item" />
                                         </form>
                                     <% end %>
@@ -32,7 +32,7 @@
             </div>
         </div>
         <div class="card-body">
-            <%= f = form_for(@changeset, Kaffy.Utils.router().kaffy_resource_path(@conn, :update, @context, @resource, @changeset.data.id), method: :put, multipart: true) %>
+            <%= f = form_for(@changeset, Kaffy.Utils.router().kaffy_resource_path(@conn, :update, @context, @resource, Kaffy.ResourceAdmin.serialize_id(@my_resource, @changeset.data)), method: :put, multipart: true) %>
                 <%= for {field, options} <- Kaffy.ResourceAdmin.form_fields(@my_resource) do %>
                     <%= if options.update != :hidden do %>
                         <%= Kaffy.ResourceForm.kaffy_input @conn, @changeset, f, field, options %>
@@ -53,7 +53,7 @@
     </div>
 
     <!-- Modal -->
-    <%= form_for(@changeset, Kaffy.Utils.router().kaffy_resource_path(@conn, :delete, @context, @resource, @changeset.data.id), method: :delete) %>
+    <%= form_for(@changeset, Kaffy.Utils.router().kaffy_resource_path(@conn, :delete, @context, @resource, Kaffy.ResourceAdmin.serialize_id(@my_resource, @changeset.data)), method: :delete) %>
     <div class="modal fade" id="delete-modal" tabindex="-1" role="dialog" aria-labelledby="delete-modal-label" aria-hidden="true">
         <div class="modal-dialog" role="document">
             <div class="modal-content">