add json order by (#728)

* add json order by

* changelog

CHANGELOG.md

@@ -9,6 +9,7 @@ In order to read more about upgrading and BC breaks have a look at the [UPGRADE
 
 + [#719](https://github.com/luyadev/luya-module-admin/pull/719) Prepare for PHP 8.1. Increased minium PHP Version to 7.4. Replaced `sizeg/jwt` with `bizley/jwt`. 
 + [#726](https://github.com/luyadev/luya-module-admin/pull/726) The signature of `luya\admin\base\JwtIdentityInterface` has changed from: `loginByJwtToken(Lcobucci\JWT\Token $token)` to `loginByJwtToken(Lcobucci\JWT\Token\Plain $token)` 
++ [#728](https://github.com/luyadev/luya-module-admin/pull/728) Added new `NgRestActiveQuery` method `jsonOrderBy()` to sort by a field which contains a json object.
 
 ## 4.4.1 (20. July 2022)
 

src/ngrest/base/NgRestActiveQuery.php

@@ -7,6 +7,7 @@
 use yii\base\InvalidConfigException;
 use yii\db\ActiveQuery;
 use yii\db\Exception;
+use yii\db\Expression;
 
 /**
  * NgRest Active Query.
@@ -74,6 +75,32 @@ public function jsonWhere($operator, $field, $key, $value)
     {
         return $this->andWhere([$operator, "JSON_EXTRACT({$field}, \"$.{$key}\")", $value]);
     }
+
+
+    /**
+     * Order by a given json key inside a field.
+     * 
+     * ```
+     * ->orderBy('title_json', 'de', 'asc')
+     * ```
+     * 
+     * Assuming the database content of `title_json` looks like this:
+     * 
+     * ```
+     * {'de': 'foobar', 'en' : 'foobar'}
+     * ```
+     *
+     * @param string $field The field name (attribute) which contains the json
+     * @param string $key The json key inside the json object to sort after
+     * @param string $direction Either `desc` or `asc`
+     * @see https://stackoverflow.com/a/70909842/4611030
+     * @return NgRestActiveQuery
+     * @since 4.5.0
+     */
+    public function jsonOrderBy($field, $key, $direction)
+    {
+        return $this->orderBy(new Expression($field . '->"$.'.$key.'" ' . $direction));
+    }
 
     /**
      * Where condition for a field inside an array.

tests/admin/ngrest/base/NgRestActiveQueryTest.php

@@ -54,6 +54,18 @@ public function testI18nWhere()
         ], $query->i18nWhere('key', 'value')->where);
     }
 
+    public function testJsonOrderBy()
+    {
+        new NgRestModelFixture([
+            'modelClass' => Lang::class,
+        ]);
+
+        $query = new NgRestActiveQuery(Lang::class);
+        $exp = $query->jsonOrderBy('attribute', 'key', 'asc')->orderBy;
+
+        $this->assertSame('attribute->"$.key" asc', $exp[0]->expression);   
+    }
+
     public function testInPool()
     {
         new NgRestModelFixture([