Added the "table" option

readme.md

@@ -201,6 +201,15 @@ Schema::create('posts', function(Blueprint $table) {
 );
 ```
 
+You can also manually specify which table and/or key to use as a reference by passing arguments to the `foreign` field like this: `logo_id:integer:foreign(images,key_name)`. You may have a logo image whose path is stored in an `images` table. This will give us:
+
+```
+$table->integer('logo_id');
+$table->foreign('logo_id')->references('key_name')->on('images');
+```
+
+Don't pass the `key_name` to default to the `id` column.
+
 Neato.
 
 ### Pivot Tables

spec/Migrations/SchemaParserSpec.php

@@ -56,4 +56,20 @@ function it_parses_schema_fields_that_want_foreign_constraints()
             ['name' => 'user_id', 'type' => 'foreign', 'arguments' => [], 'options' => ['references' => "'id'", 'on' => "'users'"]]
         ]);
     }
+
+    function it_parses_schema_fields_that_want_foreign_constraints_with_table()
+    {
+        $this->parse('logo_id:integer:foreign(images)')->shouldReturn([
+            ['name' => 'logo_id', 'type' => 'integer', 'arguments' => [], 'options' => []],
+            ['name' => 'logo_id', 'type' => 'foreign', 'arguments' => [], 'options' => ['references' => "'id'", 'on' => "'images'"]]
+        ]);
+    }
+
+    function it_parses_schema_fields_that_want_foreign_constraints_with_table_and_primaryKey()
+    {
+        $this->parse('logo_id:integer:foreign(images,images_key)')->shouldReturn([
+            ['name' => 'logo_id', 'type' => 'integer', 'arguments' => [], 'options' => []],
+            ['name' => 'logo_id', 'type' => 'foreign', 'arguments' => [], 'options' => ['references' => "'images_key'", 'on' => "'images'"]]
+        ]);
+    }
 }

src/Migrations/SchemaParser.php

@@ -26,14 +26,25 @@ public function parse($schema)
             $segments = $this->parseSegments($field);
 
             if ($this->fieldNeedsForeignConstraint($segments)) {
+
+                // Get the foreign table and key
+                $foreignField   = $segments['options']['foreign'];
+                $table = null;
+                $key   = null;
+
+                if( $foreignField != 1 ){
+                    $foreignOptions = explode(",", $foreignField);
+                    list($table, $key) = count($foreignOptions) == 2 ? $foreignOptions : [$foreignField,null];
+                }
+
                 unset($segments['options']['foreign']);
 
                 // If the user wants a foreign constraint, then
                 // we'll first add the regular field.
                 $this->addField($segments);
 
                 // And then add another field for the constraint.
-                $this->addForeignConstraint($segments);
+                $this->addForeignConstraint($segments,$table,$key);
 
                 continue;
             }
@@ -119,14 +130,23 @@ private function parseOptions($options)
     /**
      * Add a foreign constraint field to the schema.
      *
-     * @param array $segments
+     * @param array       $segments
+     * @param null|string $table
+     * @param null|string $key
      */
-    private function addForeignConstraint($segments)
+    private function addForeignConstraint($segments,$table = null, $key = null)
     {
+        if( !isset($table) )
+            $table = $this->getTableNameFromForeignKey( $segments['name'] );
+
+        if( !isset($key) )
+            $key = 'id';
+
         $string = sprintf(
-            "%s:foreign:references('id'):on('%s')",
+            "%s:foreign:references('%s'):on('%s')",
             $segments['name'],
-            $this->getTableNameFromForeignKey($segments['name'])
+            $key,
+            $table
         );
 
         $this->addField($this->parseSegments($string));