Added filter_if filter to filter if attribute value matches (#44)

README.md

@@ -28,6 +28,8 @@ Given a data array with the following format:
         'jsonVar'       =>  '{"name":"value"}',
         'description'   =>  '<p>Test paragraph.</p><!-- Comment --> <a href="#fragment">Other text</a>',
         'phone'         =>  '+08(096)90-123-45q',
+        'country'       =>  'GB',
+        'postcode'      =>  'ab12 3de',
     ];
 ```
 We can easily format it using our Sanitizer and the some of Sanitizer's default filters:
@@ -42,6 +44,8 @@ We can easily format it using our Sanitizer and the some of Sanitizer's default
         'jsonVar'       =>  'cast:array',
         'description'   =>  'strip_tags',
         'phone'         =>  'digit',
+        'country'       =>  'trim|escape|capitalize',
+        'postcode'      =>  'trim|escape|uppercase|filter_if:country,GB',
     ];
 
     $sanitizer  = new Sanitizer($data, $filters);
@@ -58,6 +62,8 @@ Which will yield:
         'jsonVar'       =>  '["name" => "value"]',
         'description'   =>  'Test paragraph. Other text',
         'phone'         =>  '080969012345',
+        'country'       =>  'GB',
+        'postcode'      =>  'AB12 3DE',
     ];
 ```
 It's usage is very similar to Laravel's Validator module, for those who are already familiar with it, although Laravel is not required to use this library.
@@ -79,7 +85,7 @@ The following filters are available out of the box:
  **format_date**    | Always takes two arguments, the date's given format and the target format, following DateTime notation.
  **strip_tags**    | Strip HTML and PHP tags using php's strip_tags
  **digit**    | Get only digit characters from the string
-
+ **filter_if** | Applies filters if an attribute exactly matches value
 
 ## Adding custom filters
 

src/Filters/FilterIf.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Waavi\Sanitizer\Filters;
+
+use Waavi\Sanitizer\Contracts\Filter;
+
+class FilterIf implements Filter
+{
+    /**
+     *  Checks if filters should run if there is value passed that matches.
+     *
+     *  @param  array   $values
+     *  @param  array   $options
+     *  @return boolean
+     */
+    public function apply($values, $options = [])
+    {
+        return array_key_exists($options[0], $values) && $values[$options[0]] === $options[1];
+    }
+}

src/Sanitizer.php

@@ -35,6 +35,7 @@ class Sanitizer
         'trim'        => \Waavi\Sanitizer\Filters\Trim::class,
         'strip_tags'  => \Waavi\Sanitizer\Filters\StripTags::class,
         'digit'       => \Waavi\Sanitizer\Filters\Digit::class,
+        'filter_if'   => \Waavi\Sanitizer\Filters\FilterIf::class,
     ];
 
     /**
@@ -129,12 +130,22 @@ public function sanitize()
         foreach ($this->rules as $attr => $rules) {
             if (Arr::has($this->data, $attr)) {
                 $value = Arr::get($this->data, $attr);
+                $original = $value;
 
+                $sanitize = true;
                 foreach ($rules as $rule) {
-                    $value = $this->applyFilter($rule['name'], $value, $rule['options']);
+                    if ($rule['name'] === 'filter_if') {
+                        $sanitize = $this->applyFilter($rule['name'], $this->data, $rule['options']);
+                    } else {
+                        $value = $this->applyFilter($rule['name'], $value, $rule['options']);
+                    }
                 }
 
-                Arr::set($sanitized, $attr, $value);
+                if ($sanitize) {
+                    Arr::set($sanitized, $attr, $value);
+                } else {
+                    Arr::set($sanitized, $attr, $original);
+                }
             }
         }
 
@@ -151,8 +162,18 @@ public function sanitize()
     protected function sanitizeAttribute($attribute, $value)
     {
         if (isset($this->rules[$attribute])) {
+            $sanitize = true;
+            $original = $value;
             foreach ($this->rules[$attribute] as $rule) {
-                $value = $this->applyFilter($rule['name'], $value, $rule['options']);
+                if ($rule['name'] === 'filter_if') {
+                    $sanitize = $this->applyFilter($rule['name'], $value, $rule['options']);
+                } else {
+                    $value = $this->applyFilter($rule['name'], $value, $rule['options']);
+                }
+            }
+
+            if (!$sanitize) {
+                return $original;
             }
         }
         return $value;

tests/Filters/FilterIfTest.php

@@ -0,0 +1,48 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+use Waavi\Sanitizer\Sanitizer;
+
+class FilterIfTest extends TestCase
+{
+    /**
+     * @param $data
+     * @param $rules
+     * @return mixed
+     */
+    public function sanitize($data, $rules)
+    {
+        $sanitizer = new Sanitizer($data, $rules);
+        return $sanitizer->sanitize();
+    }
+
+    /**
+     *  @test
+     */
+    public function it_apply_filter_if_match()
+    {
+        $data = [
+            'name' => 'HellO EverYboDy',
+        ];
+        $rules = [
+            'name' => 'uppercase|filter_if:name,HellO EverYboDy',
+        ];
+        $data = $this->sanitize($data, $rules);
+        $this->assertEquals('HELLO EVERYBODY', $data['name']);
+    }
+
+    /**
+     *  @test
+     */
+    public function it_does_not_apply_filter_if_no_match()
+    {
+        $data = [
+            'name' => 'HellO EverYboDy',
+        ];
+        $rules = [
+            'name' => 'uppercase|filter_if:name,no match',
+        ];
+        $data = $this->sanitize($data, $rules);
+        $this->assertEquals('HellO EverYboDy', $data['name']);
+    }
+}