[6.x] Add exclude_if validation rule

src/Illuminate/Validation/Concerns/ValidatesAttributes.php

@@ -1396,6 +1396,57 @@ public function validateRequiredIf($attribute, $value, $parameters)
     {
         $this->requireParameterCount(2, $parameters, 'required_if');
 
+        [$values, $other] = $this->prepareValuesAndOther($parameters);
+
+        if (in_array($other, $values)) {
+            return $this->validateRequired($attribute, $value);
+        }
+
+        return true;
+    }
+
+    /**
+     * Indicate that an attribute should be excluded when another attribute has a given value.
+     *
+     * @param  string  $attribute
+     * @param  mixed  $value
+     * @param  mixed  $parameters
+     * @return bool
+     */
+    public function validateExcludeIf($attribute, $value, $parameters)
+    {
+        $this->requireParameterCount(2, $parameters, 'exclude_if');
+
+        [$values, $other] = $this->prepareValuesAndOther($parameters);
+
+        return ! in_array($other, $values);
+    }
+
+    /**
+     * Indicate that an attribute should be excluded when another attribute does not have a given value.
+     *
+     * @param  string  $attribute
+     * @param  mixed  $value
+     * @param  mixed  $parameters
+     * @return bool
+     */
+    public function validateExcludeUnless($attribute, $value, $parameters)
+    {
+        $this->requireParameterCount(2, $parameters, 'exclude_unless');
+
+        [$values, $other] = $this->prepareValuesAndOther($parameters);
+
+        return in_array($other, $values);
+    }
+
+    /**
+     * Prepare the values and the other value for validation.
+     *
+     * @param  array  $parameters
+     * @return array
+     */
+    protected function prepareValuesAndOther($parameters)
+    {
         $other = Arr::get($this->data, $parameters[0]);
 
         $values = array_slice($parameters, 1);
@@ -1404,11 +1455,7 @@ public function validateRequiredIf($attribute, $value, $parameters)
             $values = $this->convertValuesToBoolean($values);
         }
 
-        if (in_array($other, $values)) {
-            return $this->validateRequired($attribute, $value);
-        }
-
-        return true;
+        return [$values, $other];
     }
 
     /**

src/Illuminate/Validation/Validator.php

@@ -48,6 +48,13 @@ class Validator implements ValidatorContract
      */
     protected $failedRules = [];
 
+    /**
+     * Attributes that should be excluded from the validated data.
+     *
+     * @var array
+     */
+    protected $excludeAttributes = [];
+
     /**
      * The message bag instance.
      *
@@ -177,6 +184,13 @@ class Validator implements ValidatorContract
         'Before', 'After', 'BeforeOrEqual', 'AfterOrEqual', 'Gt', 'Lt', 'Gte', 'Lte',
     ];
 
+    /**
+     * The validation rules that can exclude an attribute.
+     *
+     * @var array
+     */
+    protected $excludeRules = ['ExcludeIf', 'ExcludeUnless'];
+
     /**
      * The size related validation rules.
      *
@@ -273,9 +287,23 @@ public function passes()
         foreach ($this->rules as $attribute => $rules) {
             $attribute = str_replace('\.', '->', $attribute);
 
+            // If this attribute is a nested rule, its parent might have already
+            // been excluded. If so, we have to remove the attribute.
+            if ($this->shouldBeExcluded($attribute)) {
+                $this->removeAttribute($attribute);
+
+                continue;
+            }
+
             foreach ($rules as $rule) {
                 $this->validateAttribute($attribute, $rule);
 
+                if ($this->shouldBeExcluded($attribute)) {
+                    $this->removeAttribute($attribute);
+
+                    break;
+                }
+
                 if ($this->shouldStopValidating($attribute)) {
                     break;
                 }
@@ -292,6 +320,40 @@ public function passes()
         return $this->messages->isEmpty();
     }
 
+    /**
+     * Determine if the attribute should be excluded.
+     *
+     * @param  string  $attribute
+     *
+     * @return bool
+     */
+    protected function shouldBeExcluded($attribute)
+    {
+        foreach ($this->excludeAttributes as $excludeAttribute) {
+            if ($attribute === $excludeAttribute) {
+                return true;
+            }
+
+            if (Str::startsWith($attribute, $excludeAttribute.'.')) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Remove the given attribute.
+     *
+     * @param  string  $attribute
+     *
+     * @return void
+     */
+    protected function removeAttribute($attribute)
+    {
+        unset($this->data[$attribute], $this->rules[$attribute]);
+    }
+
     /**
      * Determine if the data fails the validation rules.
      *
@@ -475,6 +537,10 @@ protected function replaceAsterisksInParameters(array $parameters, array $keys)
      */
     protected function isValidatable($rule, $attribute, $value)
     {
+        if (in_array($rule, $this->excludeRules)) {
+            return true;
+        }
+
         return $this->presentOrRuleIsImplicit($rule, $attribute, $value) &&
                $this->passesOptionalCheck($attribute) &&
                $this->isNotNullIfMarkedAsNullable($rule, $attribute) &&
@@ -621,6 +687,12 @@ public function addFailure($attribute, $rule, $parameters = [])
             $this->passes();
         }
 
+        if (in_array($rule, $this->excludeRules)) {
+            $this->excludeAttributes[] = $attribute;
+
+            return;
+        }
+
         $this->messages->add($attribute, $this->makeReplacements(
             $this->getMessage($attribute, $rule), $attribute, $rule, $parameters
         ));