From 98d77847256b8a62b358449dbb0b0e361dd3a855 Mon Sep 17 00:00:00 2001
From: Alan Vardy <alan@vardy.cc>
Date: Tue, 18 Jun 2024 08:45:35 -0700
Subject: [PATCH] Add query modifier

---
 README.md                         | 10 ++++++++++
 config/test.exs                   |  2 +-
 docker-compose.yml                |  2 --
 lib/exzeitable/database.ex        | 21 ++++++++++++++++++++-
 lib/exzeitable/params.ex          |  1 +
 test/exzeitable/database_test.exs |  3 ++-
 6 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index d36bca3d..6c1af5c0 100644
--- a/README.md
+++ b/README.md
@@ -145,6 +145,16 @@ Note that if you are navigating to the live table using [Phoenix LiveView live_s
 - `pagination: [:top, :bottom]` Whether to show the pagination above and below
 - `text: Exzeitable.Text.Default` The translation that appears on the table, defaults to English.
 - `assigns: %{}` Passes additional assigns to socket.assigns. Keep your payload small!
+- `query_modifier: {MyModule, :my_function}` Passes the query to MyModule.my_function/2, where query can then be dynamically altered before being returned. Arguments are the query, and the `Exzeitable.Params` struct, which is how Exzeitable stores state. Return value is the query.
+
+```elixir
+defmodule MyApp.MyModule do
+  def my_function(query, _state) do
+     # Make your modifications and return the new query
+    query
+  end
+end
+```
 
 ### Field options
 
diff --git a/config/test.exs b/config/test.exs
index e6e6b88a..84a0ba4a 100644
--- a/config/test.exs
+++ b/config/test.exs
@@ -28,7 +28,7 @@ config :exzeitable, Exzeitable.Mailer, adapter: Swoosh.Adapters.Test
 config :stream_data, max_runs: 100
 
 # Print only warnings and errors during test
-config :logger, level: :warn
+config :logger, level: :warning
 
 # Initialize plugs at runtime for faster test compilation
 config :phoenix, :plug_init_mode, :runtime
diff --git a/docker-compose.yml b/docker-compose.yml
index 7a979b77..378c9ec6 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,5 +1,3 @@
-
-version: '3'
 services:
   dbserver:
     image: postgres:14.2
diff --git a/lib/exzeitable/database.ex b/lib/exzeitable/database.ex
index 6084bde1..0256466b 100644
--- a/lib/exzeitable/database.ex
+++ b/lib/exzeitable/database.ex
@@ -1,14 +1,16 @@
 defmodule Exzeitable.Database do
   @moduledoc "Database interactions"
   import Ecto.Query
+  alias Exzeitable.Params
 
   @doc "Get the data using query"
   @spec get_records(map) :: [map]
-  def get_records(%{query: query} = params) do
+  def get_records(%Params{query: query} = params) do
     query
     |> order_query(params)
     |> search_query(params)
     |> paginate_query(params)
+    |> modify_query(params)
     |> get_query(params)
   end
 
@@ -50,6 +52,23 @@ defmodule Exzeitable.Database do
     from(q in query, select: count(q.id))
   end
 
+  defp modify_query(query, %Params{query_modifier: nil}) do
+    query
+  end
+
+  defp modify_query(query, %Params{query_modifier: {mod, fun}} = params) when is_atom(mod) and is_atom(fun) do
+   apply(mod, fun, [query, params])
+  end
+
+  defp modify_query(_query, %Params{query_modifier: invalid}) do
+    raise """
+      Invalid option given for :query_modifier
+
+      Expected: {Module, :function}
+      Got:      #{inspect(invalid)}
+    """
+  end
+
   # Repo.all
   @spec get_query(Ecto.Query.t(), map) :: [map]
   defp get_query(query, %{repo: repo}), do: repo.all(query)
diff --git a/lib/exzeitable/params.ex b/lib/exzeitable/params.ex
index a9e96e01..aec33787 100644
--- a/lib/exzeitable/params.ex
+++ b/lib/exzeitable/params.ex
@@ -51,6 +51,7 @@ defmodule Exzeitable.Params do
     :module,
     :csrf_token,
     # optional
+    :query_modifier,
     :order,
     :parent,
     :belongs_to,
diff --git a/test/exzeitable/database_test.exs b/test/exzeitable/database_test.exs
index dceebfac..dbcf6a9b 100644
--- a/test/exzeitable/database_test.exs
+++ b/test/exzeitable/database_test.exs
@@ -4,9 +4,10 @@ defmodule Exzeitable.DatabaseTest do
   alias Exzeitable.Database
   alias TestWeb.User
 
-  @assigns %{
+  @assigns %Exzeitable.Params{
     query: from(u in User),
     parent: nil,
+    csrf_token: "234",
     routes: TestWeb.Router.Helpers,
     repo: TestWeb.Repo,
     path: :user_path,