Object based unique and exists rules for validation. (#15809)

* allow toString objects

* work on fluent validation rules

* Add tests for new features.

* add tests

* remove group

* Applied fixes from StyleCI (#15808)

src/Illuminate/Validation/DatabasePresenceVerifier.php

@@ -2,6 +2,7 @@
 
 namespace Illuminate\Validation;
 
+use Closure;
 use Illuminate\Support\Str;
 use Illuminate\Database\ConnectionResolverInterface;
 
@@ -52,7 +53,13 @@ public function getCount($collection, $column, $value, $excludeId = null, $idCol
         }
 
         foreach ($extra as $key => $extraValue) {
-            $this->addWhere($query, $key, $extraValue);
+            if ($extraValue instanceof Closure) {
+                $query->where(function ($query) use ($extraValue) {
+                    $extraValue($query);
+                });
+            } else {
+                $this->addWhere($query, $key, $extraValue);
+            }
         }
 
         return $query->count();
@@ -72,7 +79,13 @@ public function getMultiCount($collection, $column, array $values, array $extra
         $query = $this->table($collection)->whereIn($column, $values);
 
         foreach ($extra as $key => $extraValue) {
-            $this->addWhere($query, $key, $extraValue);
+            if ($extraValue instanceof Closure) {
+                $query->where(function ($query) use ($extraValue) {
+                    $extraValue($query);
+                });
+            } else {
+                $this->addWhere($query, $key, $extraValue);
+            }
         }
 
         return $query->count();

src/Illuminate/Validation/Rule.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace Illuminate\Validation;
+
+class Rule
+{
+    /**
+     * Get a exists constraint builder instance.
+     *
+     * @param  string  $table
+     * @param  string  $column
+     * @return \Illuminate\Validation\Rules\Exists
+     */
+    public static function exists($table, $column = 'NULL')
+    {
+        return new Rules\Exists($table, $column);
+    }
+
+    /**
+     * Get a unique constraint builder instance.
+     *
+     * @param  string  $table
+     * @param  string  $column
+     * @return \Illuminate\Validation\Rules\Unique
+     */
+    public static function unique($table, $column = 'NULL')
+    {
+        return new Rules\Unique($table, $column);
+    }
+}

src/Illuminate/Validation/Rules/Exists.php

@@ -0,0 +1,149 @@
+<?php
+
+namespace Illuminate\Validation\Rules;
+
+use Closure;
+
+class Exists
+{
+    /**
+     * The table to run the query against.
+     *
+     * @var string
+     */
+    protected $table;
+
+    /**
+     * The column to check for existence on.
+     *
+     * @var string
+     */
+    protected $column;
+
+    /**
+     * There extra where clauses for the query.
+     *
+     * @var array
+     */
+    protected $wheres = [];
+
+    /**
+     * The custom query callback.
+     *
+     * @var \Closure|null
+     */
+    protected $using;
+
+    /**
+     * Create a new exists rule instance.
+     *
+     * @param  string  $table
+     * @param  string  $column
+     * @return void
+     */
+    public function __construct($table, $column = 'NULL')
+    {
+        $this->table = $table;
+        $this->column = $column;
+    }
+
+    /**
+     * Set a "where" constraint on the query.
+     *
+     * @param  string  $column
+     * @param  string  $value
+     * @return $this
+     */
+    public function where($column, $value = null)
+    {
+        if ($column instanceof Closure) {
+            return $this->using($column);
+        }
+
+        $this->wheres[] = compact('column', 'value');
+
+        return $this;
+    }
+
+    /**
+     * Set a "where not" constraint on the query.
+     *
+     * @param  string  $column
+     * @param  string  $value
+     * @return $this
+     */
+    public function whereNot($column, $value)
+    {
+        return $this->where($column, '!'.$value);
+    }
+
+    /**
+     * Set a "where null" constraint on the query.
+     *
+     * @param  string  $column
+     * @return $this
+     */
+    public function whereNull($column)
+    {
+        return $this->where($column, 'NULL');
+    }
+
+    /**
+     * Set a "where not null" constraint on the query.
+     *
+     * @param  string  $column
+     * @return $this
+     */
+    public function whereNotNull($column)
+    {
+        return $this->where($column, 'NOT_NULL');
+    }
+
+    /**
+     * Register a custom query callback.
+     *
+     * @param  \Closure  $callback
+     */
+    public function using(Closure $callback)
+    {
+        $this->using = $callback;
+
+        return $this;
+    }
+
+    /**
+     * Format the where clauses.
+     *
+     * @return string
+     */
+    protected function formatWheres()
+    {
+        return collect($this->wheres)->map(function ($where) {
+            return $where['column'].','.$where['value'];
+        })->implode(',');
+    }
+
+    /**
+     * Get the custom query callbacks for the rule.
+     *
+     * @return array
+     */
+    public function queryCallbacks()
+    {
+        return $this->using ? [$this->using] : [];
+    }
+
+    /**
+     * Convert the rule to a validation string.
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return rtrim(sprintf('exists:%s,%s,%s',
+            $this->table,
+            $this->column,
+            $this->formatWheres()
+        ), ',');
+    }
+}

src/Illuminate/Validation/Rules/Unique.php

@@ -0,0 +1,180 @@
+<?php
+
+namespace Illuminate\Validation\Rules;
+
+use Closure;
+
+class Unique
+{
+    /**
+     * The table to run the query against.
+     *
+     * @var string
+     */
+    protected $table;
+
+    /**
+     * The column to check for uniqueness on.
+     *
+     * @var string
+     */
+    protected $column;
+
+    /**
+     * The ID that should be ignored.
+     *
+     * @var mixed
+     */
+    protected $ignore;
+
+    /**
+     * The name of the ID column.
+     *
+     * @var string
+     */
+    protected $idColumn = 'id';
+
+    /**
+     * There extra where clauses for the query.
+     *
+     * @var array
+     */
+    protected $wheres = [];
+
+    /**
+     * The custom query callback.
+     *
+     * @var \Closure|null
+     */
+    protected $using;
+
+    /**
+     * Create a new unique rule instance.
+     *
+     * @param  string  $table
+     * @param  string  $column
+     * @return void
+     */
+    public function __construct($table, $column = 'NULL')
+    {
+        $this->table = $table;
+        $this->column = $column;
+    }
+
+    /**
+     * Set a "where" constraint on the query.
+     *
+     * @param  string  $column
+     * @param  string  $value
+     * @return $this
+     */
+    public function where($column, $value = null)
+    {
+        if ($column instanceof Closure) {
+            return $this->using($column);
+        }
+
+        $this->wheres[] = compact('column', 'value');
+
+        return $this;
+    }
+
+    /**
+     * Set a "where not" constraint on the query.
+     *
+     * @param  string  $column
+     * @param  string  $value
+     * @return $this
+     */
+    public function whereNot($column, $value)
+    {
+        return $this->where($column, '!'.$value);
+    }
+
+    /**
+     * Set a "where null" constraint on the query.
+     *
+     * @param  string  $column
+     * @return $this
+     */
+    public function whereNull($column)
+    {
+        return $this->where($column, 'NULL');
+    }
+
+    /**
+     * Set a "where not null" constraint on the query.
+     *
+     * @param  string  $column
+     * @return $this
+     */
+    public function whereNotNull($column)
+    {
+        return $this->where($column, 'NOT_NULL');
+    }
+
+    /**
+     * Ignore the given ID during the unique check.
+     *
+     * @param  mixed  $id
+     * @param  string  $idColumn
+     * @return $this
+     */
+    public function ignore($id, $idColumn = 'id')
+    {
+        $this->ignore = $id;
+        $this->idColumn = $idColumn;
+
+        return $this;
+    }
+
+    /**
+     * Register a custom query callback.
+     *
+     * @param  \Closure  $callback
+     */
+    public function using(Closure $callback)
+    {
+        $this->using = $callback;
+
+        return $this;
+    }
+
+    /**
+     * Format the where clauses.
+     *
+     * @return string
+     */
+    protected function formatWheres()
+    {
+        return collect($this->wheres)->map(function ($where) {
+            return $where['column'].','.$where['value'];
+        })->implode(',');
+    }
+
+    /**
+     * Get the custom query callbacks for the rule.
+     *
+     * @return array
+     */
+    public function queryCallbacks()
+    {
+        return $this->using ? [$this->using] : [];
+    }
+
+    /**
+     * Convert the rule to a validation string.
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return rtrim(sprintf('unique:%s,%s,%s,%s,%s',
+            $this->table,
+            $this->column,
+            $this->ignore ?: 'NULL',
+            $this->idColumn,
+            $this->formatWheres()
+        ), ',');
+    }
+}