From 4a220885596557dc29aac011a4b63853edd217f5 Mon Sep 17 00:00:00 2001
From: Toby Zerner <toby.zerner@gmail.com>
Date: Mon, 3 Jan 2022 14:27:58 +1100
Subject: [PATCH] Add `Context::sortRequested()` method to determine if a sort
 field has been requested

---
 src/Context.php      | 32 ++++++++++++++++++++++++--------
 src/ResourceType.php | 13 +------------
 src/functions.php    | 11 +++++++++++
 3 files changed, 36 insertions(+), 20 deletions(-)

diff --git a/src/Context.php b/src/Context.php
index 613dc33..1563461 100644
--- a/src/Context.php
+++ b/src/Context.php
@@ -60,6 +60,14 @@ class Context
         );
     }
 
+    /**
+     * Get the parsed JSON:API payload.
+     */
+    public function getBody(): ?array
+    {
+        return $this->request->getParsedBody() ?: json_decode($this->request->getBody()->getContents(), true);
+    }
+
     public function response(callable $callback): void
     {
         $this->listeners['response'][] = $callback;
@@ -79,6 +87,22 @@ class Context
         return in_array($field, explode(',', $queryParams['fields'][$type]));
     }
 
+    /**
+     * Determine whether a sort field has been requested.
+     */
+    public function sortRequested(string $field): bool
+    {
+        if ($sortString = $this->getRequest()->getQueryParams()['sort'] ?? null) {
+            foreach (parse_sort_string($sortString) as [$name, $direction]) {
+                if ($name === $field) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
     /**
      * Get the value of a filter.
      */
@@ -86,12 +110,4 @@ class Context
     {
         return $this->request->getQueryParams()['filter'][$name] ?? null;
     }
-
-    /**
-     * Get parsed JsonApi payload
-     */
-    public function getBody(): ?array
-    {
-        return $this->request->getParsedBody() ?: json_decode($this->request->getBody()->getContents(), true);
-    }
 }
diff --git a/src/ResourceType.php b/src/ResourceType.php
index 5d9e823..131129d 100644
--- a/src/ResourceType.php
+++ b/src/ResourceType.php
@@ -84,7 +84,7 @@ final class ResourceType
         $customSorts = $schema->getSorts();
         $fields = $schema->getFields();
 
-        foreach ($this->parseSortString($sortString) as [$name, $direction]) {
+        foreach (parse_sort_string($sortString) as [$name, $direction]) {
             if (
                 isset($customSorts[$name])
                 && evaluate($customSorts[$name]->getVisible(), [$context])
@@ -107,17 +107,6 @@ final class ResourceType
         }
     }
 
-    private function parseSortString(string $string): array
-    {
-        return array_map(function ($field) {
-            if ($field[0] === '-') {
-                return [substr($field, 1), 'desc'];
-            } else {
-                return [$field, 'asc'];
-            }
-        }, explode(',', $string));
-    }
-
     /**
      * Apply the resource type's filters to a query.
      */
diff --git a/src/functions.php b/src/functions.php
index dbe3f23..93d5e61 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -68,3 +68,14 @@ function set_value(array &$data, Field $field, $value): void
 {
     $data[$field->getLocation()][$field->getName()] = $value;
 }
+
+function parse_sort_string(string $string): array
+{
+    return array_map(function ($field) {
+        if ($field[0] === '-') {
+            return [substr($field, 1), 'desc'];
+        } else {
+            return [$field, 'asc'];
+        }
+    }, explode(',', $string));
+}