Expand API validation.

app/Api/V1/Controllers/TransactionController.php

@@ -215,7 +215,7 @@ class TransactionController extends Controller
         }
 
         $transactions = $collector->getJournals();
-        $resource     = new Item($transactions->first(), new TransactionTransformer($this->parameters), 'transactions');
+        $resource     = new FractalCollection($transactions, new TransactionTransformer($this->parameters), 'transactions');
 
         return response()->json($manager->createData($resource)->toArray())->header('Content-Type', 'application/vnd.api+json');
     }

app/Api/V1/Requests/TransactionRequest.php

@@ -165,6 +165,7 @@ class TransactionRequest extends Request
                 $this->emptySplitDescriptions($validator);
                 $this->foreignCurrencyInformation($validator);
                 $this->validateAccountInformation($validator);
+                $this->validateSplitAccounts($validator);
             }
         );
     }
@@ -368,6 +369,9 @@ class TransactionRequest extends Request
     {
         $data         = $validator->getData();
         $transactions = $data['transactions'] ?? [];
+        if(!isset($data['type'])) {
+            return;
+        }
         foreach ($transactions as $index => $transaction) {
 
             $sourceId        = isset($transaction['source_id']) ? intval($transaction['source_id']) : null;
@@ -404,10 +408,57 @@ class TransactionRequest extends Request
                     $this->assetAccountExists($validator, $destinationId, $destinationName, $idField, $nameField);
                     break;
                 default:
-                    throw new FireflyException(sprintf('The validator cannot handle transaction type "%s".', $data['type']));
+                    throw new FireflyException(sprintf('The validator cannot handle transaction type "%s" in validateAccountInformation().', $data['type']));
 
             }
         }
     }
 
+    /**
+     * @param Validator $validator
+     *
+     * @throws FireflyException
+     */
+    protected function validateSplitAccounts(Validator $validator)
+    {
+        $data  = $validator->getData();
+        $count = isset($data['transactions']) ? count($data['transactions']) : 0;
+        if ($count < 2) {
+            return;
+        }
+        // collect all source ID's and destination ID's, if present:
+        $sources      = [];
+        $destinations = [];
+
+        foreach ($data['transactions'] as $transaction) {
+            $sources[]      = isset($transaction['source_id']) ? intval($transaction['source_id']) : 0;
+            $destinations[] = isset($transaction['destination_id']) ? intval($transaction['destination_id']) : 0;
+        }
+        $destinations = array_unique($destinations);
+        $sources      = array_unique($sources);
+        // switch on type:
+        switch ($data['type']) {
+            case 'withdrawal':
+                if (count($sources) > 1) {
+                    $validator->errors()->add('transactions.0.source_id', trans('validation.all_accounts_equal'));
+                }
+                break;
+            case 'deposit':
+                if (count($destinations) > 1) {
+                    $validator->errors()->add('transactions.0.destination_id', trans('validation.all_accounts_equal'));
+                }
+                break;
+            case 'transfer':
+                if (count($sources) > 1 || count($destinations) > 1) {
+                    $validator->errors()->add('transactions.0.source_id', trans('validation.all_accounts_equal'));
+                    $validator->errors()->add('transactions.0.destination_id', trans('validation.all_accounts_equal'));
+                }
+                break;
+            default:
+                throw new FireflyException(sprintf('The validator cannot handle transaction type "%s" in validateSplitAccounts().', $data['type']));
+        }
+
+        return;
+    }
+
 }

resources/lang/en_US/validation.php

@@ -29,6 +29,7 @@ return [
     'file_already_attached'          => 'Uploaded file ":name" is already attached to this object.',
     'file_attached'                  => 'Succesfully uploaded file ":name".',
     'must_exist'                     => 'The ID in field :attribute does not exist in the database.',
+    'all_accounts_equal'             => 'All accounts in this field must be equal.',
     'belongs_user'                   => 'This value is invalid for this field.',
     'at_least_one_transaction'       => 'Need at least one transaction.',
     'require_currency_info'          => 'The content of this field is invalid without currency information.',