diff --git a/src/db/Capacitor.php b/src/db/Capacitor.php
index 0c2f161..6341741 100644
--- a/src/db/Capacitor.php
+++ b/src/db/Capacitor.php
@@ -64,7 +64,7 @@ class Capacitor implements ITransactor {
     return $this->db()->inTransaction();
   }
 
-  function beginTransaction(?callable $func=null): void {
+  function beginTransaction(?callable $func=null, bool $commit=true): void {
     if ($this->subManageTransactions === null && $this->subChannels !== null) {
       foreach ($this->subChannels as $channel) {
         $name = $channel->getName();
@@ -81,10 +81,12 @@ class Capacitor implements ITransactor {
       $commited = false;
       try {
         func::call($func, $this);
-        $this->commit();
-        $commited = true;
+        if ($commit) {
+          $this->commit();
+          $commited = true;
+        }
       } finally {
-        if (!$commited) $this->rollback();
+        if ($commit && !$commited) $this->rollback();
       }
     }
   }
diff --git a/src/db/ITransactor.php b/src/db/ITransactor.php
index a485a7b..d9e2ccc 100644
--- a/src/db/ITransactor.php
+++ b/src/db/ITransactor.php
@@ -13,8 +13,16 @@ interface ITransactor {
 
   function inTransaction(): bool;
 
-  /** si $func!==null, la lancer puis commiter la transaction */
-  function beginTransaction(?callable $func=null): void;
+  /**
+   * démarrer une transaction
+   *
+   * si $func!==null, l'apppeler. ensuite, si $commit===true, commiter la
+   * transaction. si une erreur se produit lors de l'appel de la fonction,
+   * annuler la transaction
+   *
+   * $func est appelée avec la signature ($this)
+   */
+  function beginTransaction(?callable $func=null, bool $commit=true): void;
 
   function commit(): void;
 
diff --git a/src/db/pdo/Pdo.php b/src/db/pdo/Pdo.php
index 50bf576..393a310 100644
--- a/src/db/pdo/Pdo.php
+++ b/src/db/pdo/Pdo.php
@@ -165,7 +165,7 @@ class Pdo implements IDatabase {
     return $this->db()->inTransaction();
   }
 
-  function beginTransaction(?callable $func=null): void {
+  function beginTransaction(?callable $func=null, bool $commit=true): void {
     $this->db()->beginTransaction();
     if ($this->transactors !== null) {
       foreach ($this->transactors as $transactor) {
@@ -176,10 +176,12 @@ class Pdo implements IDatabase {
       $commited = false;
       try {
         func::call($func, $this);
-        $this->commit();
-        $commited = true;
+        if ($commit) {
+          $this->commit();
+          $commited = true;
+        }
       } finally {
-        if (!$commited) $this->rollback();
+        if ($commit && !$commited) $this->rollback();
       }
     }
   }
diff --git a/src/db/sqlite/Sqlite.php b/src/db/sqlite/Sqlite.php
index 2c30763..dc8266f 100644
--- a/src/db/sqlite/Sqlite.php
+++ b/src/db/sqlite/Sqlite.php
@@ -200,7 +200,7 @@ class Sqlite implements IDatabase {
     return $this->inTransaction;
   }
 
-  function beginTransaction(?callable $func=null): void {
+  function beginTransaction(?callable $func=null, bool $commit=true): void {
     $this->db()->exec("begin");
     $this->inTransaction = true;
     if ($this->transactors !== null) {
@@ -212,10 +212,12 @@ class Sqlite implements IDatabase {
       $commited = false;
       try {
         func::call($func, $this);
-        $this->commit();
-        $commited = true;
+        if ($commit) {
+          $this->commit();
+          $commited = true;
+        }
       } finally {
-        if (!$commited) $this->rollback();
+        if ($commit && !$commited) $this->rollback();
       }
     }
   }
diff --git a/src/ext/spreadsheet/SpoutBuilder.php b/src/ext/spreadsheet/SpoutBuilder.php
index e05bfba..ad0d72b 100644
--- a/src/ext/spreadsheet/SpoutBuilder.php
+++ b/src/ext/spreadsheet/SpoutBuilder.php
@@ -4,6 +4,7 @@ namespace nur\sery\ext\spreadsheet;
 use nur\sery\file\csv\AbstractBuilder;
 use nur\sery\file\csv\TAbstractBuilder;
 use nur\sery\os\path;
+use nur\sery\php\func;
 use nur\sery\php\time\Date;
 use nur\sery\php\time\DateTime;
 use nur\sery\web\http;
@@ -77,7 +78,7 @@ class SpoutBuilder extends AbstractBuilder {
   /**
    * @param string|int|null $wsname
    */
-  function setWsname($wsname): self {
+  function setWsname($wsname, ?array $params=null): self {
     $ss = $this->ss;
     $this->rowStyle = self::STYLE_ROW;
     if ($this->firstSheet) {
@@ -85,11 +86,42 @@ class SpoutBuilder extends AbstractBuilder {
       $ws = $ss->getCurrentSheet();
     } else {
       $ws = $ss->addNewSheetAndMakeItCurrent();
+      $this->wroteHeaders = false;
+      $this->built = false;
     }
     if ($wsname !== null) $ws->setName($wsname);
-    $ws->setSheetView((new SheetView())
-      ->setFreezeRow(2)
-    );
+    $sheetView = (new SheetView())
+      ->setFreezeRow(2);
+    $ws->setSheetView($sheetView);
+    if ($params !== null) {
+      if (array_key_exists("schema", $params)) {
+        $this->schema = $params["schema"] ?? null;
+      }
+      if (array_key_exists("headers", $params)) {
+        $this->headers = $params["headers"] ?? null;
+      }
+      if (array_key_exists("rows", $params)) {
+        $rows = $params["rows"] ?? null;
+        if (is_callable($rows)) $rows = $rows();
+        $this->rows = $rows;
+      }
+      if (array_key_exists("cook_func", $params)) {
+        $cookFunc = $params["cook_func"] ?? null;
+        $cookCtx = $cookArgs = null;
+        if ($cookFunc !== null) {
+          func::ensure_func($cookFunc, $this, $cookArgs);
+          $cookCtx = func::_prepare($cookFunc);
+        }
+        $this->cookCtx = $cookCtx;
+        $this->cookArgs = $cookArgs;
+      }
+      if (array_key_exists("type_numeric", $params)) {
+        $this->typeNumeric = boolval($params["type_numeric"] ?? static::TYPE_NUMERIC);
+      }
+      if (array_key_exists("type_date", $params)) {
+        $this->typeDate = boolval($params["type_date"] ?? static::TYPE_DATE);
+      }
+    }
     return $this;
   }
 
diff --git a/src/file/csv/AbstractBuilder.php b/src/file/csv/AbstractBuilder.php
index 8df2e39..a21b87a 100644
--- a/src/file/csv/AbstractBuilder.php
+++ b/src/file/csv/AbstractBuilder.php
@@ -105,7 +105,7 @@ abstract class AbstractBuilder extends TempStream implements IBuilder {
     }
     if ($rows !== null) {
       foreach ($rows as $row) {
-        $this->write($row);
+        $this->write(cl::with($row));
       }
     }
     if ($unsetRows) $this->rows = null;
@@ -132,14 +132,30 @@ abstract class AbstractBuilder extends TempStream implements IBuilder {
 
   abstract protected function _checkOk(): bool;
 
-  function build(?iterable $rows=null): bool {
-    $this->_build($rows);
-    return $this->_checkOk();
+  protected bool $built = false, $closed = false;
+
+  function build(?iterable $rows=null, bool $close=true): bool {
+    $ok = true;
+    if (!$this->built) {
+      $this->_build($rows);
+      $this->built = true;
+    }
+    if ($close && !$this->closed) {
+      $ok = $this->_checkOk();
+      $this->closed = true;
+    }
+    return $ok;
   }
 
   function sendFile(?iterable $rows=null): int {
-    $this->_build($rows);
-    if (!$this->_checkOk()) return 0;
+    if (!$this->built) {
+      $this->_build($rows);
+      $this->built = true;
+    }
+    if (!$this->closed) {
+      if (!$this->_checkOk()) return 0;
+      $this->closed = true;
+    }
     $this->sendHeaders();
     return $this->fpassthru();
   }