Added EncodedImage rule

README.md

@@ -39,6 +39,7 @@ The following validation rules are currently available:
 | DisposableEmail | validation.disposable_email | Requires the presence of an email address which is not disposable |
 | DoesNotExist    | validation.does_not_exist   | Requires that the given value is not present in a given database table / column - see class for details |
 | Decimal         | validation.decimal          | Requires that the given value is a decimal with an appropriate format - see class for details |
+| EncodedImage    | validation.encoded_image    | Requires that the given value is a base64-encoded image of a given mime type - see class for details |
 
 The package will receive new rules over time, however since these updates will not be breaking changes, they will not receive major version numbers unless Laravel changes in such a way that the package requires a re-write.
 

src/EncodedImage.php

@@ -0,0 +1,84 @@
+<?php
+
+// Namespace
+namespace Alphametric\Validation\Rules;
+
+// Using directives
+use Illuminate\Http\UploadedFile;
+
+// Encoded image rule
+class EncodedImage extends Rule
+{
+
+	/**
+	 * Pointer to the temporary file.
+	 *
+	 **/
+	protected $file;
+
+
+
+	/**
+	 * Write the given data to a temporary file.
+	 *
+	 * @param string $data.
+	 * @return UploadedFile.
+	 *
+	 **/
+	protected function createTemporaryFile($data)
+	{
+		$this->file = tmpfile();
+
+		fwrite($this->file, base64_decode(str_after($data, 'base64,')));
+
+		return new UploadedFile(
+			stream_get_meta_data($this->file)['uri'], 'image',
+			'text/plain', null, null, true
+		);
+	}
+
+
+
+    /**
+     * Determine if the validation rule passes.
+     *
+     * The rule requires a single parameter, which is
+	 * the expected mime type of the file e.g. png, jpeg etc.
+     *
+     * @param string $attribute.
+     * @param mixed $value.
+     * @return bool.
+     *
+     **/
+    public function passes($attribute, $value)
+    {
+		if (! starts_with($value, "data:image/{$this->parameters[0]};base64,")) {
+			return false;
+		}
+
+		$result = validator(['file' => $this -> createTemporaryFile($value)], ['file' => 'image'])
+			   -> passes();
+
+		fclose($this->file);
+
+		return $result;
+    }
+
+
+
+    /**
+     * Get the validation error message.
+     *
+     * @param none.
+     * @return string.
+     *
+     **/
+    public function message()
+    {
+        return Helper::getLocalizedErrorMessage(
+            'encoded_image',
+            "The :attribute must be a valid {$this->parameters[0]} image"
+        );
+    }
+
+}

tests/EncodedImageTest.php

@@ -0,0 +1,63 @@
+<?php
+
+// Namespace
+namespace Alphametric\Validation\Rules\Tests;
+
+// Using directives
+use Alphametric\Validation\Rules\EncodedImage;
+use Orchestra\Testbench\TestCase as Orchestra;
+
+// Encoded image test
+class EncodedImageTest extends Orchestra
+{
+
+	/**
+	 * Retrieve the contents of a given file.
+	 *
+	 * @param string $file_name.
+	 * @return string.
+	 *
+	 **/
+	protected function getFile($file_name)
+	{
+		$path = realpath(__DIR__ . '/..') . "/support/assets/$file_name";
+
+		$extension = pathinfo($path, PATHINFO_EXTENSION);
+
+		return "data:image/{$extension};base64," . base64_encode(file_get_contents($path));
+	}
+
+
+
+	/**
+	 * Generate an invalid image file with a given mime type.
+	 *
+	 * @param string $mime.
+	 * @return string.
+	 *
+	 **/
+	protected function invalidImage($mime = "")
+	{
+		return "data:image/{$mime};base64," . base64_encode("not an image file");
+	}
+
+
+
+	/** @test */
+	public function a_encoded_jpeg_image_can_be_validated()
+	{
+		// Define the validation rule
+		$png_rule  = ['image' => [new EncodedImage('png')]];
+		$jpeg_rule = ['image' => [new EncodedImage('jpeg')]];
+
+		// Execute the tests
+		$this->assertFalse(validator(['image' => $this -> getFile('image.jpeg')], $png_rule)->passes());
+		$this->assertTrue(validator(['image' => $this -> getFile('image.png')], $png_rule)->passes());
+		$this->assertTrue(validator(['image' => $this -> getFile('image.jpeg')], $jpeg_rule)->passes());
+		$this->assertFalse(validator(['image' => $this -> getFile('image.png')], $jpeg_rule)->passes());
+		$this->assertFalse(validator(['image' => $this -> invalidImage('image.jpeg')], $jpeg_rule)->passes());
+		$this->assertFalse(validator(['image' => $this -> invalidImage('image.png')], $jpeg_rule)->passes());
+		$this->assertFalse(validator(['image' => $this -> invalidImage()], $jpeg_rule)->passes());
+	}
+
+}