improvement: add paginate_by_default? option to read actions (#2648)

Author: juanm07

.formatter.exs

@@ -223,6 +223,7 @@ spark_locals_without_parens = [
   on: 1,
   only_when_valid?: 1,
   page: 1,
+  paginate_by_default?: 1,
   pagination: 0,
   pagination: 1,
   parse_attribute: 1,

documentation/dsls/DSL-Ash.Resource.md

@@ -1554,6 +1554,7 @@ Adds pagination options to a resource
 | [`max_page_size`](#actions-read-pagination-max_page_size){: #actions-read-pagination-max_page_size } | `pos_integer` | `250` | The maximum amount of records that can be requested in a single page |
 | [`stable_sort`](#actions-read-pagination-stable_sort){: #actions-read-pagination-stable_sort } | `any` |  | A stable sort statement to add to a query (after any existing sorts). Only added if the sort does not already contain a stable sort (sorting on fields that uniquely identify a record). Defaults to the primary key. |
 | [`required?`](#actions-read-pagination-required?){: #actions-read-pagination-required? } | `boolean` | `true` | Whether or not pagination can be disabled (by passing `page: false` to `Ash.Api.read!/2`, or by having `required?: false, default_limit: nil` set). Only relevant if some pagination configuration is supplied. |
+| [`paginate_by_default?`](#actions-read-pagination-paginate_by_default?){: #actions-read-pagination-paginate_by_default? } | `boolean` | `false` | Whether or not to paginate by default when pagination is not required and no page parameters are provided. |
 
 
 

lib/ash/actions/read/read.ex

@@ -3832,7 +3832,9 @@ defmodule Ash.Actions.Read do
           action.pagination.default_limit ->
         Keyword.put(page_opts, :limit, action.pagination.default_limit)
 
-      is_nil(page_opts) and action.pagination.required? and not relationship? ->
+      is_nil(page_opts) and
+        (action.pagination.required? or action.pagination.paginate_by_default?) and
+          not relationship? ->
         if action.pagination.default_limit do
           [limit: action.pagination.default_limit]
         else

lib/ash/resource/actions/read.ex

@@ -149,6 +149,12 @@ defmodule Ash.Resource.Actions.Read do
       doc:
         "Whether or not pagination can be disabled (by passing `page: false` to `Ash.Api.read!/2`, or by having `required?: false, default_limit: nil` set). Only relevant if some pagination configuration is supplied.",
       default: true
+    ],
+    paginate_by_default?: [
+      type: :boolean,
+      doc:
+        "Whether or not to paginate by default when pagination is not required and no page parameters are provided.",
+      default: false
     ]
   ]
 
@@ -160,6 +166,7 @@ defmodule Ash.Resource.Actions.Read do
       countable: false,
       stable_sort: nil,
       required?: false,
+      paginate_by_default?: false,
       keyset?: false,
       offset?: false,
       __spark_metadata__: nil

test/actions/pagination_test.exs

@@ -64,6 +64,14 @@ defmodule Ash.Actions.PaginationTest do
         pagination offset?: true, countable: true, required?: false
       end
 
+      read :paginate_by_default do
+        pagination offset?: true,
+                   countable: true,
+                   required?: false,
+                   paginate_by_default?: true,
+                   default_limit: 3
+      end
+
       read :offset_countable_by_default do
         pagination offset?: true, countable: :by_default, required?: false
       end
@@ -308,6 +316,14 @@ defmodule Ash.Actions.PaginationTest do
 
       assert %{results: [%{name: "3"}]} = Ash.page!(page, :self)
     end
+
+    test "paginate_by_default? applies default limit when no page opts" do
+      assert %Ash.Page.Offset{results: results} =
+               User
+               |> Ash.read!(action: :paginate_by_default)
+
+      assert Enum.count(results) == 3
+    end
   end
 
   describe "keyset pagination with nil fields" do