Add support for when;

README.md

@@ -34,13 +34,35 @@ class DataModelHelper
 
 ## Helper Methods
 
+- [when](#when): Create a map of any type by using
 - [mapOf](#mapof): Create a map of any type by using
 - [pregReplace](#pregreplace): Perform a regular expression search and replace.
 - [pregMatch](#pregmatch): Perform a regular expression match.
 - [isUrl](#isurl): Validates a url.
 - [isEmail](#isemail): Validates an email.
 - [isMultiple](#ismultiple): Validate a value is a multiple of another.
 
+### `when`
+
+Use `when` to call a function based on a condition.
+
+```php
+class User
+{
+    use \Zerotoprod\DataModel\DataModel;
+    use \Zerotoprod\DataModelHelper\DataModelHelper;
+
+    #[Describe([
+        'cast' => [self::class, 'when'],
+        'eval' => '$value >= $context["value_2"]' // The expression to evaluate.
+        'true' => [MyAction::class, 'passed'],    // Optional. Invoked when condition is true.
+        'false' => [MyAction::class, 'failed'],   // Optional. Invoked when condition is true.
+        'required',                               // Throws PropertyRequiredException when value not present.
+    ])]
+    public string $value;
+}
+```
+
 ### `mapOf`
 
 Create a map of any type by using the `DataModelHelper::mapOf()` method.

src/DataModelHelper.php

@@ -314,4 +314,40 @@ public static function isMultiple(mixed $value, array $context, ?ReflectionAttri
 
         return $value;
     }
+
+    /**
+     * Determine if a given value is a valid URL.
+     *  ```
+     *   #[Describe([
+     *       'cast' => [self::class, 'when'],
+     *       'eval' => '$value >= $context["value_2"]' // The expression to evaluate.
+     *       'true' => [MyAction::class, 'passed'],    // Optional. Invoked when condition is true.
+     *       'false' => [MyAction::class, 'failed'],   // Optional. Invoked when condition is true.
+     *       'required',                               // Throws PropertyRequiredException when value not present.
+     *   ])]
+     *  ```
+     */
+    public static function when(mixed $value, array $context, ?ReflectionAttribute $Attribute, ReflectionProperty $Property): ?string
+    {
+        $args = $Attribute?->getArguments()[0];
+        if ((!empty($args['required']) || in_array('required', $args, true))
+            && !isset($context[$Property->getName()])
+        ) {
+            throw new PropertyRequiredException("Property `\${$Property->getName()}` is required.");
+        }
+
+        if (!$value && $Property->getType()?->allowsNull()) {
+            return null;
+        }
+
+        if (eval("return {$args['eval']};")) {
+            if (isset($args['true'])) {
+                return call_user_func($args['true'], $value, $context, $Attribute, $Property);
+            }
+        } elseif (isset($args['false'])) {
+            return call_user_func($args['false'], $value, $context, $Attribute, $Property);
+        }
+
+        return $value;
+    }
 }

tests/Unit/When/Eval/EvalTest.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Tests\Unit\When\Eval;
+
+use PHPUnit\Framework\Attributes\Test;
+use Tests\TestCase;
+
+class EvalTest extends TestCase
+{
+    #[Test] public function true(): void
+    {
+        $User = User::from([
+            User::value => 100,
+        ]);
+
+        self::assertEquals(1, $User->value);
+    }
+
+    #[Test] public function false(): void
+    {
+        $User = User::from([
+            User::value => 2,
+        ]);
+
+        self::assertEquals(0, $User->value);
+    }
+}

tests/Unit/When/Eval/User.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace Tests\Unit\When\Eval;
+
+use Zerotoprod\DataModel\DataModel;
+use Zerotoprod\DataModel\Describe;
+use Zerotoprod\DataModelHelper\DataModelHelper;
+
+class User
+{
+    use DataModel;
+    use DataModelHelper;
+
+    public const value = 'value';
+
+    #[Describe([
+        'cast' => [self::class, 'when'],
+        'eval' => '$value >= 10',
+        'true' => [self::class, 'true'],
+        'false' => [self::class, 'false'],
+    ])]
+    public int $value;
+
+    public static function true(): int
+    {
+        return 1;
+    }
+    public static function false(): int
+    {
+        return 0;
+    }
+}

tests/Unit/When/Nullable/NullTest.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace Tests\Unit\When\Nullable;
+
+use PHPUnit\Framework\Attributes\Test;
+use Tests\TestCase;
+
+class NullTest extends TestCase
+{
+    #[Test] public function valid(): void
+    {
+        $User = User::from([
+            User::value => null,
+        ]);
+
+        self::assertNull($User->value);
+    }
+}

tests/Unit/When/Nullable/User.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Tests\Unit\When\Nullable;
+
+use Zerotoprod\DataModel\DataModel;
+use Zerotoprod\DataModel\Describe;
+use Zerotoprod\DataModelHelper\DataModelHelper;
+
+class User
+{
+    use DataModel;
+    use DataModelHelper;
+
+    public const value = 'value';
+
+    #[Describe([
+        'cast' => [self::class, 'when'],
+    ])]
+    public ?int $value;
+
+    public static function false(): int
+    {
+        return 0;
+    }
+}

tests/Unit/When/Required/RequiredTest.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace Tests\Unit\When\Required;
+
+use PHPUnit\Framework\Attributes\Test;
+use Tests\TestCase;
+use Zerotoprod\DataModel\PropertyRequiredException;
+
+class RequiredTest extends TestCase
+{
+    #[Test] public function required(): void
+    {
+        $this->expectException(PropertyRequiredException::class);
+        $this->expectExceptionMessage('Property `$value` is required.');
+        User::from();
+    }
+}

tests/Unit/When/Required/User.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Tests\Unit\When\Required;
+
+use Zerotoprod\DataModel\DataModel;
+use Zerotoprod\DataModel\Describe;
+use Zerotoprod\DataModelHelper\DataModelHelper;
+
+class User
+{
+    use DataModel;
+    use DataModelHelper;
+
+    public const value = 'value';
+
+    #[Describe([
+        'cast' => [self::class, 'when'],
+        'required'
+    ])]
+    public string $value;
+}

tests/Unit/When/Value/User.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Tests\Unit\When\Value;
+
+use Zerotoprod\DataModel\DataModel;
+use Zerotoprod\DataModel\Describe;
+use Zerotoprod\DataModelHelper\DataModelHelper;
+
+class User
+{
+    use DataModel;
+    use DataModelHelper;
+
+    public const value = 'value';
+
+    #[Describe([
+        'cast' => [self::class, 'when'],
+        'eval' => '$value >= 10',
+        'false' => [self::class, 'false'],
+    ])]
+    public int $value;
+
+    public static function true(): int
+    {
+        return 1;
+    }
+    public static function false(): int
+    {
+        return 0;
+    }
+}

tests/Unit/When/Value/ValueTest.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace Tests\Unit\When\Value;
+
+use PHPUnit\Framework\Attributes\Test;
+use Tests\TestCase;
+
+class ValueTest extends TestCase
+{
+    #[Test] public function value(): void
+    {
+        $User = User::from([
+            User::value => 100,
+        ]);
+
+        self::assertEquals(100, $User->value);
+    }
+}