diff --git a/TODO.md b/TODO.md
index 1c71852..0637136 100644
--- a/TODO.md
+++ b/TODO.md
@@ -73,6 +73,53 @@
   ~~~
   bien entendu, bien que ce ne soit pas démontré ici, le premier argument
   (l'en-tête) est un contenu, pas seulement une chaine
+
+  chaque élément de contenu défini header, body et footer
+  ~~~php
+  $element = ["header" => [], "body" => [], "footer" => []];
+  ~~~
+
+  colspan peut être utilisé dans header, body ou footer. si spécifié dans
+  $element, colspan s'applique à body
+  ~~~php
+  # les deux suivants sont équivalents
+  $element = ["myheader", "mybody", "colspan" => 2, "myfooter"];
+  $element = [
+    "header" => [
+      "content" => "myheader",
+    ],
+    "body" => [
+      "content" => "mybody",
+      "colspan" => 2,
+    ],
+    "footer" => [
+      "content" => "myfooter",
+    ],
+  ];
+  ~~~
+
+  si $element est une fonction, il retourne la valeur de l'élement
+  ~~~php
+  $element = function() {
+    return ["header", "body"];
+  }
+  ~~~
+
+  clé "enabled" permet d'activer dynamiquement un élément
+  ~~~php
+  $element = function() {
+    return ["header", "body", "enabled" => $includeElement];
+  }
+  ~~~
+
+  clé "func" pour spécifier la fonction dans un contexte statique
+  ~~~php
+  $element = ["func" => [My::class, "get_element"]];
+  ~~~
+  func n'est considéré que si $element était un tableau à la base
+  s'il y a d'autres clés, elles sont fusionnées avec le résultat de $func()
+  (dont les clés sont prioritaires)
+
 * Cursor::dyn permet d'insérer une valeur qui sera évaluée plus tard lors de la
   résolution du contenu
 * pour Cursor, CTable, etc., un paramètre "params_func" permet de générer une
diff --git a/nur_src/v/icon.php b/nur_src/v/icon.php
index 1d20ac1..b062e7a 100644
--- a/nur_src/v/icon.php
+++ b/nur_src/v/icon.php
@@ -99,6 +99,9 @@ class icon {
   static final function plus($suffix=null, ?string $alt=null): array { return self::manager()->getIcon("plus", $suffix, $alt); }
   static final function minus($suffix=null, ?string $alt=null): array { return self::manager()->getIcon("minus", $suffix, $alt); }
 
+  static final function start($suffix=null, ?string $alt=null): array { return self::manager()->getIcon("play", $suffix, $alt); }
+  static final function stop($suffix=null, ?string $alt=null): array { return self::manager()->getIcon("stop", $suffix, $alt); }
+
   # template:
   #static final function xxx($suffix=null, ?string $alt=null): array { return self::manager()->getIcon("xxx", $suffix, $alt); }
 }
diff --git a/src/cache/CacheChannel.php b/src/cache/CacheChannel.php
index 4272a99..68fde79 100644
--- a/src/cache/CacheChannel.php
+++ b/src/cache/CacheChannel.php
@@ -1,116 +1,128 @@
 <?php
 namespace nulib\cache;
 
+use IteratorAggregate;
 use nulib\cl;
 use nulib\db\CapacitorChannel;
-use nulib\php\time\DateTime;
-use nulib\php\time\Delay;
+use nulib\db\CapacitorStorage;
+use nulib\ext\utils;
+use nulib\php\func;
+use Traversable;
 
-class CacheChannel extends CapacitorChannel {
-  /** @var int durée de vie par défaut du cache */
-  const DURATION = "1D"; // jusqu'au lendemain
+class CacheChannel extends CapacitorChannel implements IteratorAggregate {
+  static function with(?iterable $rows=null, $cursorId=null, ?CapacitorStorage $storage=null): self {
+    $storage ??= cache::storage();
+    $channel = (new static($cursorId))->initStorage($storage);
+    if ($rows !== null) $channel->build($rows);
+    return $channel;
+  }
 
-  const INCLUDES = null;
-
-  const EXCLUDES = null;
+  const NAME = "cache";
+  const TABLE_NAME = "cache";
 
   const COLUMN_DEFINITIONS = [
-    "group_id" => "varchar(64) not null",
-    "id" => "varchar(64) not null",
-    "date_start" => "datetime",
-    "duration_" => "text",
-    "primary key (group_id, id)",
+    "group_id_" => "varchar(32) not null", // groupe de curseur
+    "id_" => "varchar(128) not null", // nom du curseur
+    "key_index_" => "integer not null",
+    "key_" => "varchar(128) not null",
+    "search_" => "varchar(255)",
+
+    "primary key (group_id_, id_, key_index_)",
   ];
 
-  static function get_cache_ids($id): array {
-    if (is_array($id)) {
-      $keys = array_keys($id);
-      if (array_key_exists("group_id", $id)) $groupIdKey = "group_id";
-      else $groupIdKey = $keys[1] ?? null;
-      $groupId = $id[$groupIdKey] ?? "";
-      if (array_key_exists("id", $id)) $idKey = "id";
-      else $idKey = $keys[0] ?? null;
-      $id = $id[$idKey] ?? "";
-    } else {
-      $groupId = "";
-    }
-    if (preg_match('/^(.*\\\\)?([^\\\\]+)$/', $groupId, $ms)) {
-      # si le groupe est une classe, faire un hash du package pour limiter la
-      # longueur du groupe
-      [$package, $groupId] = [$ms[1], $ms[2]];
-      $package = substr(md5($package), 0, 4);
-      $groupId = "${groupId}_$package";
-    }
-    return ["group_id" => $groupId, "id" => $id];
+  const ADD_COLUMNS = null;
+
+  protected function COLUMN_DEFINITIONS(): ?array {
+    return cl::merge(self::COLUMN_DEFINITIONS, static::ADD_COLUMNS);
   }
 
-  function __construct(?string $duration=null, ?string $name=null) {
-    parent::__construct($name);
-    $this->duration = $duration ?? static::DURATION;
-    $this->includes = static::INCLUDES;
-    $this->excludes = static::EXCLUDES;
+  /**
+   * @param array|string $cursorId
+   */
+  function __construct($cursorId) {
+    parent::__construct();
+    cache::verifix_id($cursorId);
+    [
+      "group_id" => $this->groupId,
+      "id" => $this->id,
+    ] = $cursorId;
   }
 
-  protected string $duration;
+  protected string $groupId;
 
-  protected ?array $includes;
+  protected string $id;
 
-  protected ?array $excludes;
+  function getCursorId(): array {
+    return [
+      "group_id" => $this->groupId,
+      "id" => $this->id,
+    ];
+  }
 
-  function getItemValues($item): ?array {
-    return cl::merge(self::get_cache_ids($item), [
-      "item" => null,
+  function getBaseFilter(): ?array {
+    return [
+      "group_id_" => $this->groupId,
+      "id_" => $this->id,
+    ];
+  }
+
+  protected int $index = 0;
+
+  protected function getSearch($item): ?string {
+    $search = cl::filter_n(cl::with($item));
+    $search = implode(" ", $search);
+    return substr($search, 0, 255);
+  }
+
+  function getItemValues($item, $key=null): ?array {
+    $index = $this->index++;
+    $key = $key ?? $index;
+    $key = substr(strval($key), 0, 128);
+    $addColumns = static::ADD_COLUMNS ?? [];
+    $addColumns = cl::select($item,
+      array_filter(array_keys($addColumns), function ($key) {
+        return is_string($key);
+      }));
+    return cl::merge($addColumns, [
+      "group_id_" => $this->groupId,
+      "id_" => $this->id,
+      "key_index_" => $index,
+      "key_" => $key,
+      "search_" => $this->getSearch($item),
     ]);
   }
 
-  function onCreate($item, array $row, ?array $alwaysNull, ?string $duration=null): ?array {
-    $now = new DateTime();
-    $duration ??= $this->duration;
-    return [
-      "date_start" => $now,
-      "duration" => new Delay($duration, $now),
-    ];
+  function reset(bool $recreate=false): void {
+    $this->index = 0;
+    parent::reset($recreate);
   }
 
-  function onUpdate($item, array $row, array $prow, ?string $duration=null): ?array {
-    $now = new DateTime();
-    $duration ??= $this->duration;
-    return [
-      "date_start" => $now,
-      "duration" => new Delay($duration, $now),
-    ];
-  }
-
-  function shouldUpdate($id, bool $noCache=false): bool {
-    if ($noCache) return true;
-
-    $cacheIds = self::get_cache_ids($id);
-    $groupId = $cacheIds["group_id"];
-    if ($groupId) {
-      $includes = $this->includes;
-      $shouldInclude = $includes !== null && in_array($groupId, $includes);
-      $excludes = $this->excludes;
-      $shouldExclude = $excludes !== null && in_array($groupId, $excludes);
-      if (!$shouldInclude || $shouldExclude) return true;
+  function chargeAll(?iterable $items, $func=null, ?array $args=null): int {
+    $this->index = 0;
+    if ($items === null) return 0;
+    $count = 0;
+    if ($func !== null) $func = func::with($func, $args)->bind($this);
+    foreach ($items as $key => $item) {
+      $count += $this->charge($item, $func, [$key]);
     }
-
-    $found = false;
-    $expired = false;
-    $this->each($cacheIds,
-      function($row) use (&$found, &$expired) {
-        $found = true;
-        $expired = $row["duration"]->isElapsed();
-      });
-    return !$found || $expired;
+    return $count;
   }
 
-  function setCached($id, ?string $duration=null): void {
-    $cacheIds = self::get_cache_ids($id);
-    $this->charge($cacheIds, null, [$duration]);
+  function build(?iterable $items): self {
+    $this->delete(null);
+    $this->chargeAll($items);
+    return $this;
   }
 
-  function resetCached($id) {
-    $cacheIds = self::get_cache_ids($id);
-    $this->delete($cacheIds);
+  function getIterator(): Traversable {
+    $rows = $this->dbAll([
+      "cols" => ["key_", "item__"],
+      "where" => $this->getBaseFilter(),
+    ]);
+    foreach ($rows as $row) {
+      $key = $row["key_"];
+      $item = $this->unserialize($row["item__"]);
+      yield $key => $item;
+    }
   }
 }
diff --git a/src/cache/CacheDataChannel.php b/src/cache/CacheDataChannel.php
deleted file mode 100644
index af885d6..0000000
--- a/src/cache/CacheDataChannel.php
+++ /dev/null
@@ -1,53 +0,0 @@
-<?php
-namespace nulib\cache;
-
-use Closure;
-use IteratorAggregate;
-use nulib\cache\CacheChannel;
-use nulib\cache\cache;
-use nulib\cl;
-use nulib\db\CapacitorChannel;
-use Traversable;
-
-class CacheDataChannel extends CapacitorChannel implements IteratorAggregate {
-  const COLUMN_DEFINITIONS = [
-    "key" => "varchar(128) primary key not null",
-    "all_values" => "mediumtext",
-  ];
-
-  function __construct($id, callable $builder, ?string $duration=null) {
-    $this->cacheIds = $cacheIds = CacheChannel::get_cache_ids($id);
-    $this->builder = Closure::fromCallable($builder);
-    $this->duration = $duration;
-    $name = "{$cacheIds["group_id"]}-{$cacheIds["id"]}";
-    parent::__construct($name);
-  }
-
-  protected array $cacheIds;
-
-  protected Closure $builder;
-
-  protected ?string $duration = null;
-
-  function getItemValues($item): ?array {
-    $key = array_keys($item)[0];
-    $row = $item[$key];
-    return [
-      "key" => $key,
-      "item" => $row,
-      "all_values" => implode(" ", cl::filter_n(cl::with($row))),
-    ];
-  }
-
-  function getIterator(): Traversable {
-    $cm = cache::get();
-    if ($cm->shouldUpdate($this->cacheIds)) {
-      $this->capacitor->reset();
-      foreach (($this->builder)() as $key => $row) {
-        $this->charge([$key => $row]);
-      }
-      $cm->setCached($this->cacheIds, $this->duration);
-    }
-    return $this->discharge(false);
-  }
-}
diff --git a/src/cache/CacheFile.php b/src/cache/CacheFile.php
index 3feb150..a4684f7 100644
--- a/src/cache/CacheFile.php
+++ b/src/cache/CacheFile.php
@@ -3,6 +3,7 @@ namespace nulib\cache;
 
 use Exception;
 use nulib\cv;
+use nulib\ext\utils;
 use nulib\file;
 use nulib\file\SharedFile;
 use nulib\os\path;
@@ -18,6 +19,11 @@ class CacheFile extends SharedFile {
 
   const EXT = ".cache";
 
+  static function with($data, ?string $file=null): self {
+    if ($data instanceof self) return $data;
+    else return new static($file, $data);
+  }
+
   protected function ensure_source($source): CacheData {
     if ($source instanceof CacheData) return $source;
     if (cv::subclass_of($source, CacheData::class)) return new $source();
@@ -25,11 +31,8 @@ class CacheFile extends SharedFile {
     throw ValueException::invalid_type($source, CacheData::class);
   }
 
-  function __construct($file, ?array $params=null) {
-    if ($file === null) {
-      $rand = bin2hex(random_bytes(8));
-      $file = path::join(sys_get_temp_dir(), $rand);
-    }
+  function __construct(?string $file, $data=null, ?array $params=null) {
+    $file ??= path::join(sys_get_temp_dir(), utils::uuidgen());
     $file = path::ensure_ext($file, self::EXT);
     $this->basedir = path::dirname($file);
     $basename = path::filename($file);
@@ -38,7 +41,7 @@ class CacheFile extends SharedFile {
     $this->overrideDuration = $params["override_duration"] ?? false;
     $this->readonly = $params["readonly"] ?? false;
     $this->cacheNull = $params["cache_null"] ?? false;
-    $data = $params["data"] ?? null;
+    $data ??= $params["data"] ?? null;
     $this->sources = null;
     if ($data === null) {
       $this->source = null;
@@ -112,6 +115,8 @@ class CacheFile extends SharedFile {
 
   protected ?Delay $duration;
 
+  protected $data;
+
   protected ?array $datafilenames;
 
   /** charger les données. le fichier a déjà été verrouillé en lecture */
@@ -121,6 +126,7 @@ class CacheFile extends SharedFile {
       [
         "start" => $start,
         "duration" => $duration,
+        "data" => $data,
         "datafiles" => $datafilenames,
       ] = $this->unserialize(null, false, true);
       if ($this->overrideDuration) {
@@ -130,10 +136,12 @@ class CacheFile extends SharedFile {
     } else {
       $start = null;
       $duration = null;
+      $data = null;
       $datafilenames = [];
     }
     $this->start = $start;
     $this->duration = $duration;
+    $this->data = $data;
     $this->datafilenames = $datafilenames;
   }
 
@@ -163,15 +171,16 @@ class CacheFile extends SharedFile {
     $this->serialize([
       "start" => $this->start,
       "duration" => $this->duration,
+      "data" => $this->data,
       "datafiles" => $datafilenames,
     ], false, true);
   }
 
-  protected function loadData(string $datafile) {
+  protected function loadDatafile(string $datafile) {
     return file::reader($datafile)->unserialize();
   }
 
-  protected function saveData(string $datafile, $data): void {
+  protected function saveDatafile(string $datafile, $data): void {
     file::writer($datafile)->serialize($data);
   }
 
@@ -182,10 +191,10 @@ class CacheFile extends SharedFile {
   }
 
   protected function unlinkFiles(bool $datafilesOnly=false): void {
-    if (!$datafilesOnly) @unlink($this->file);
     foreach ($this->datafilenames as $datafilename) {
       $this->unlinkDatafile($datafilename);
     }
+    if (!$datafilesOnly) @unlink($this->file);
   }
 
   /** tester si $value peut être mis en cache */
@@ -197,26 +206,28 @@ class CacheFile extends SharedFile {
 
   protected ?Delay $oduration;
 
+  protected $odata;
+
   protected ?array $odatafilenames;
 
   protected function beforeAction() {
     $this->loadMetadata();
     $this->ostart = cv::clone($this->start);
     $this->oduration = cv::clone($this->duration);
+    $this->odata = cv::clone($this->data);
     $this->odatafilenames = cv::clone($this->datafilenames);
   }
 
   protected function afterAction() {
-    $start = $this->start;
+    $modified = false;
+    if ($this->start != $this->ostart) $modified = true;
     $duration = $this->duration;
     $oduration = $this->oduration;
-    $datafilenames = $this->datafilenames;
-    $modified = false;
-    if ($start != $this->ostart) $modified = true;
     if ($duration === null || $oduration === null) $modified = true;
     elseif ($duration->getDest() != $oduration->getDest()) $modified = true;
-    # égalité stricte uniquement pour $datafiles qui est un array
-    if ($datafilenames !== $this->odatafilenames) $modified = true;
+    # égalité stricte uniquement pour $data et $datafiles
+    if ($this->data !== $this->odata) $modified = true;
+    if ($this->datafilenames !== $this->odatafilenames) $modified = true;
     if ($modified && !$this->readonly) {
       $this->lockWrite();
       $this->saveMetadata();
@@ -232,8 +243,13 @@ class CacheFile extends SharedFile {
       $this->afterAction();
       return $result;
     } finally {
+      $this->ostart = null;
+      $this->oduration = null;
+      $this->odata = null;
+      $this->odatafilenames = null;
       $this->start = null;
       $this->duration = null;
+      $this->data = null;
       $this->datafilenames = null;
       $this->unlock(true);
     }
@@ -243,51 +259,95 @@ class CacheFile extends SharedFile {
     return null;
   }
 
-  function get($data=null, bool $noCache=false) {
-    return $this->action(function () use ($data, $noCache) {
-      $source = $this->getSource($data);
-      $dataname = $source->getName();
-      $datafilename = ".{$this->basename}.{$dataname}".self::EXT;
-      $datafile = path::join($this->basedir, $datafilename);
+  protected function refreshData($data, bool $noCache) {
+    $defaultSource = $data === null;
+    $source = $this->getSource($data);
+    $dataname = $source->getName();
+    $datafilename = ".{$this->basename}.{$dataname}".self::EXT;
+    $datafile = path::join($this->basedir, $datafilename);
 
-      $updateMetadata = $this->shouldUpdate($noCache);
-      $updateData = !array_key_exists($datafilename, $this->datafilenames);
-      if (!$this->readonly && ($updateMetadata || $updateData)) {
-        $this->lockWrite();
-        if ($updateMetadata) {
-          # il faut refaire tout le cache
-          $this->unlinkFiles(true);
-          $this->start = null;
-          $this->duration = null;
-          $updateData = true;
-        }
+    $updateMetadata = $this->shouldUpdate($noCache);
+    if ($defaultSource) $updateData = $this->data === null;
+    else $updateData = !array_key_exists($datafilename, $this->datafilenames);
+    if (!$this->readonly && ($updateMetadata || $updateData)) {
+      $this->lockWrite();
+      if ($updateMetadata) {
+        # il faut refaire tout le cache
+        $this->unlinkFiles(true);
+        $this->start = null;
+        $this->duration = null;
+        $this->data = null;
+        $updateData = true;
+      }
+      if ($defaultSource) {
         if ($updateData) {
-          # calculer un fichier
+          # calculer la valeur
           try {
             $data = $source->get();
           } catch (Exception $e) {
-            # ne pas garder le fichier en cas d'exception
+            # le fichier n'est pas mis à jour, mais ce n'est pas gênant: lors
+            # des futurs appels, l'exception continuera d'être lancée ou la
+            # valeur sera finalement mise à jour
+            throw $e;
+          }
+        } else {
+          $data = $this->data;
+        }
+        if ($this->shouldCache($data)) $this->data = $data;
+        else $this->data = $data = null;
+      } else {
+        if ($updateData) {
+          # calculer la valeur
+          try {
+            $data = $source->get();
+          } catch (Exception $e) {
+            # ne pas garder le fichier destination en cas d'exception
             $this->unlinkDatafile($datafile);
             throw $e;
           }
         } elseif (file_exists($datafile)) {
-          $data = $this->loadData($datafile);
+          $data = $this->loadDatafile($datafile);
         } else {
           $data = null;
         }
         if ($this->shouldCache($data)) {
-          $this->saveData($datafile, $data);
+          $this->saveDatafile($datafile, $data);
           $this->datafilenames[$datafilename] = true;
         } else {
           # ne pas garder le fichier s'il ne faut pas mettre en cache
           $this->unlinkDatafile($datafile);
         }
-      } elseif (file_exists($datafile)) {
-        $data = $this->loadData($datafile);
-      } else {
-        $data = null;
       }
-      return $data;
+    } elseif ($defaultSource) {
+      $data = $this->data;
+    } elseif (file_exists($datafile)) {
+      $data = $this->loadDatafile($datafile);
+    } else {
+      $data = null;
+    }
+    return $data;
+  }
+
+  /**
+   * s'assurer que le cache est à jour avec les données les plus récentes. si
+   * les données sont déjà présentes dans le cache et n'ont pas encore expirées
+   * cette méthode est un NOP
+   */
+  function refresh(bool $noCache=false): self {
+    $this->action(function() use ($noCache) {
+      $source = $this->source;
+      if ($source !== null) $datas = [null];
+      else $datas = array_keys($this->sources);
+      foreach ($datas as $data) {
+        $this->refreshData($data, $noCache);
+      }
+    });
+    return $this;
+  }
+
+  function get($data=null, bool $noCache=false) {
+    return $this->action(function () use ($data, $noCache) {
+      return $this->refreshData($data, $noCache);
     });
   }
 
diff --git a/src/cache/CacheManager.php b/src/cache/CacheManager.php
new file mode 100644
index 0000000..2b134c9
--- /dev/null
+++ b/src/cache/CacheManager.php
@@ -0,0 +1,68 @@
+<?php
+namespace nulib\cache;
+
+use nulib\cl;
+
+/**
+ * Class CacheManager: un gestionnaire de cache permettant de désactiver la mise
+ * en cache d'une valeur dans le cadre d'une session.
+ *
+ * en effet, si on désactive le cache, il doit être réactivé après que la valeur
+ * est calculée, pour éviter qu'une valeur soit calculée encore et encore dans
+ * une session de travail
+ */
+class CacheManager {
+  function __construct(?array $includes=null, ?array $excludes=null) {
+    $this->shouldCaches = [];
+    $this->defaultCache = true;
+    $this->includes = $includes;
+    $this->excludes = $excludes;
+  }
+
+  /**
+   * @var array tableau {id => shouldCache} indiquant si l'élément id doit être
+   * mis en cache
+   */
+  protected array $shouldCaches;
+
+  /**
+   * @var bool valeur par défaut de shouldCache si la valeur n'est pas trouvée
+   * dans $shouldCache
+   */
+  protected bool $defaultCache;
+
+  /**
+   * @var array|null groupes à toujours inclure dans le cache. pour les
+   * identifiants de ces groupe, {@link self::shouldCache()} retourne toujours
+   * true.
+   *
+   * $excludes est prioritaire par rapport à $includes
+   */
+  protected ?array $includes;
+
+  /**
+   * @var array|null groupes à exclure de la mise en cache. la mise en cache est
+   * toujours calculée pour les identifiants de ces groupes.
+   */
+  protected ?array $excludes;
+
+  function setNoCache(bool $noCache=true, bool $reset=true): self {
+    if ($reset) $this->shouldCaches = [];
+    $this->defaultCache = !$noCache;
+    return $this;
+  }
+
+  function shouldCache(string $id, ?string $groupId=null, bool $reset=true): bool {
+    if ($groupId !== null) {
+      $includes = $this->includes;
+      $shouldInclude = $includes !== null && in_array($groupId, $includes);
+      $excludes = $this->excludes;
+      $shouldExclude = $excludes !== null && in_array($groupId, $excludes);
+      if ($shouldInclude && !$shouldExclude) return true;
+    }
+    $cacheId = "$groupId-$id";
+    $shouldCache = cl::get($this->shouldCaches, $cacheId, $this->defaultCache);
+    $this->shouldCaches[$cacheId] = $reset?: $shouldCache;
+    return $shouldCache;
+  }
+}
diff --git a/src/cache/cache.php b/src/cache/cache.php
index 46f93b0..b0a25c2 100644
--- a/src/cache/cache.php
+++ b/src/cache/cache.php
@@ -2,11 +2,10 @@
 namespace nulib\cache;
 
 use nulib\app;
-use nulib\cache\CacheChannel;
-use nulib\cache\CacheDataChannel;
-use nulib\db\Capacitor;
 use nulib\db\CapacitorStorage;
 use nulib\db\sqlite\SqliteStorage;
+use nulib\ext\utils;
+use nulib\php\func;
 
 class cache {
   protected static ?string $dbfile = null;
@@ -17,30 +16,67 @@ class cache {
 
   protected static ?CapacitorStorage $storage = null;
 
+  static function storage(): CapacitorStorage {
+    return self::$storage ??= new SqliteStorage(self::dbfile());
+  }
+
   static function set_storage(CapacitorStorage $storage): CapacitorStorage {
     return self::$storage = $storage;
   }
 
-  protected static function get_storage(): CapacitorStorage {
-    return self::$storage ??= new SqliteStorage(self::dbfile());
+  protected static ?CacheManager $manager = null;
+
+  static function manager(): CacheManager {
+    return self::$manager ??= new CacheManager();
   }
 
-  protected static ?CacheChannel $channel = null;
-
-  static function set(?CacheChannel $channel): CacheChannel {
-    $channel ??= new CacheChannel();
-    new Capacitor(self::get_storage(), $channel);
-    return self::$channel = $channel;
+  static function set_manager(CacheManager $manager): CacheManager {
+    return self::$manager = $manager;
   }
 
-  static function get(): CacheChannel {
-    if (self::$channel !== null) return self::$channel;
-    else return self::set(null);
+  static function nc(bool $noCache=true, bool $reset=false): void {
+    self::manager()->setNoCache($noCache, $reset);
   }
 
-  static function new(?CacheDataChannel $channel, $id=null, ?callable $builder=null): CacheDataChannel {
-    $channel ??= new CacheDataChannel($id, $builder);
-    new Capacitor(self::get_storage(), $channel);
-    return $channel;
+  protected static function should_cache(string $id, ?string $groupId=null, bool $reset=true): bool {
+    return self::manager()->shouldCache($id, $groupId, $reset);
+  }
+
+  static function verifix_id(&$cacheId): void {
+    $cacheId ??= utils::uuidgen();
+    if (is_array($cacheId)) {
+      $keys = array_keys($cacheId);
+      if (array_key_exists("id", $cacheId)) $idKey = "id";
+      else $idKey = $keys[0] ?? null;
+      $id = strval($cacheId[$idKey] ?? "");
+      if (array_key_exists("group_id", $cacheId)) $groupIdKey = "group_id";
+      else $groupIdKey = $keys[1] ?? null;
+      $groupId = strval($cacheId[$groupIdKey] ?? "");
+    } else {
+      $id = strval($cacheId);
+      $groupId = "";
+    }
+    # si le groupe ou le nom sont trop grand, en faire un hash
+    if (strlen($groupId) > 32) $groupId = md5($groupId);
+    if (strlen($id) > 128) $id = substr($id, 0, 128 - 32).md5($id);
+    $cacheId = ["group_id" => $groupId, "id" => $id];
+  }
+
+  static function get(callable $compute, $dataId=null, ?string $file=null) {
+    self::verifix_id($dataId);
+    $file ??= "{$dataId["group_id"]}_{$dataId["id"]}";
+    $noCache = !self::should_cache($dataId["id"], $dataId["group_id"]);
+    return CacheFile::with($compute, $file)->get(null, $noCache);
+  }
+
+  static function all(?iterable $rows, $cursorId=null, ?string $file=null): iterable {
+    self::verifix_id($cursorId);
+    $file ??= "{$cursorId["group_id"]}_{$cursorId["id"]}_rows";
+    $ccursorId = new CacheFile($file, function() use ($rows, $cursorId) {
+      CacheChannel::with(null, $cursorId)->build($rows);
+      return $cursorId;
+    });
+    $noCache = !self::should_cache($cursorId["id"], $cursorId["group_id"]);
+    return CacheChannel::with(null, $ccursorId->get(null, $noCache));
   }
 }
diff --git a/src/cli/AbstractStorageApp.php b/src/cli/AbstractStorageApp.php
index 9526d74..81504b1 100644
--- a/src/cli/AbstractStorageApp.php
+++ b/src/cli/AbstractStorageApp.php
@@ -98,7 +98,7 @@ abstract class AbstractStorageApp extends Application {
           }
         }
         $first = true;
-        $capacitor->each($filter, function ($item, $row) use (&$first) {
+        $capacitor->each($filter, function ($row) use (&$first) {
           if ($first) $first = false;
           else echo "---\n";
           yaml::dump($row);
diff --git a/src/cli/NucacheApp.php b/src/cli/NucacheApp.php
index 7248f47..6845ee5 100644
--- a/src/cli/NucacheApp.php
+++ b/src/cli/NucacheApp.php
@@ -87,7 +87,7 @@ class NucacheApp extends Application {
       switch ($this->action) {
       case self::ACTION_READ:
         if ($showSection) msg::section($file);
-        $cache = new CacheFile($file, [
+        $cache = new CacheFile($file, null, [
           "readonly" => true,
           "duration" => "INF",
           "override_duration" => true,
@@ -96,7 +96,7 @@ class NucacheApp extends Application {
         break;
       case self::ACTION_INFOS:
         if ($showSection) msg::section($file);
-        $cache = new CacheFile($file, [
+        $cache = new CacheFile($file, null, [
           "readonly" => true,
         ]);
         yaml::dump($cache->getInfos());
diff --git a/src/schema/TODO.md b/src/schema/TODO.md
index 1f5cda4..c318ab2 100644
--- a/src/schema/TODO.md
+++ b/src/schema/TODO.md
@@ -21,6 +21,33 @@
 
 * `ScalarSchema::from_property()`
 
+* pour le support des propriétés des objets, il faudrait pouvoir spécifier
+  comment instancier l'objet. je ne sais pas si ça doit se mettre au niveau du
+  type, du schéma, ou autre
+  ~~~php
+  Schema::ns($schema, [
+    "rt" => ["?string", "required" => true],
+    "rtd" => ["?int", "required" => true, "default" => 42],
+    "ot" => ["?int"],
+    "otd" => ["?string", "default" => "hello"],
+    "ot2" => ["int"],
+    "" => ["assoc",
+      "class" => MyClass::class,
+    ],
+  ]);
+
+  # peut provisionner la classe suivante
+  class MyClass {
+    public ?string $rt;
+    public ?int $rtd = 42;
+    public ?int $ot = null;
+    public ?string $otd = "hello";
+    public int $ot2 = 0;
+  }
+  ~~~
+  il y a potentiellement un problème d'oeuf et de poule si on se sert de ce
+  genre de définitions pour autogénérer la classe
+
 * l'argument $format de AssocWrapper::format() est un tableau associatif
   `[$key => $format]`
   cela permet de spécifier des format spécifiques pour certains champs.
diff --git a/tbin/test-nucache.php b/tbin/test-nucache.php
index 802926f..d148ee6 100755
--- a/tbin/test-nucache.php
+++ b/tbin/test-nucache.php
@@ -17,22 +17,22 @@ function show(string $prefix, CacheFile $cache, bool $dumpInfos=true): void {
 //system("rm -f *.cache .*.cache");
 
 $what = [
-  //"null",
+  "null",
   "one",
-  //"two",
-  //"three",
+  "two",
+  "three",
 ];
 $duration = 10;
 
 if (in_array("null", $what)) {
-  $null = new CacheFile("null", [
+  $null = new CacheFile("null", null, [
     "duration" => $duration,
   ]);
   show("null", $null);
 }
 
 if (in_array("one", $what)) {
-  $one = new class("one", [
+  $one = new class("one", null, [
     "duration" => $duration,
   ]) extends CacheFile {
     protected function compute() {
@@ -43,11 +43,10 @@ if (in_array("one", $what)) {
 }
 
 if (in_array("two", $what)) {
-  $two = new CacheFile("two", [
+  $two = new CacheFile("two", new CacheData(function () {
+    return 2;
+  }), [
     "duration" => $duration,
-    "data" => new CacheData(function () {
-      return 2;
-    }),
   ]);
   show("two", $two);
 }
@@ -62,12 +61,10 @@ if (in_array("three", $what)) {
   });
 
   $three = new CacheFile("three", [
-    "data" => [
-      "data31" => $data31,
-      $data31, # name=data31name
-      "data32" => $data32,
-      $data32, # name=""
-    ],
+    "data31" => $data31,
+    $data31, # name=data31name
+    "data32" => $data32,
+    $data32, # name=""
   ]);
   Txx("three.0=", $three->get("data31"));
   Txx("three.1=", $three->get("data31name"));
diff --git a/tests/.gitignore b/tests/.gitignore
new file mode 100644
index 0000000..69bea44
--- /dev/null
+++ b/tests/.gitignore
@@ -0,0 +1,2 @@
+*.db*
+*.cache
diff --git a/tests/cache/CacheChannelTest.php b/tests/cache/CacheChannelTest.php
new file mode 100644
index 0000000..2de3842
--- /dev/null
+++ b/tests/cache/CacheChannelTest.php
@@ -0,0 +1,38 @@
+<?php
+namespace nulib\cache;
+
+use nulib\output\msg;
+
+class CacheChannelTest extends _TestCase {
+  const DATA = [
+    "fr" => ["a" => "un", "b" => "deux"],
+    "eng" => ["a" => "one", "b" => "two"],
+    ["a" => 1, "b" => 2],
+  ];
+
+  function testUsage() {
+    $channel = CacheChannel::with(self::DATA, "numbers", self::$storage);
+    $count = 0;
+    foreach ($channel as $key => $item) {
+      msg::info("one: $key => {$item["a"]}");
+      $count++;
+    }
+    self::assertSame(3, $count);
+  }
+
+  function testAddColumns() {
+    $channel = (new class("numbers") extends CacheChannel {
+      const NAME = "numbersac";
+      const TABLE_NAME = self::NAME;
+      const ADD_COLUMNS = [
+        "a" => "varchar(30)",
+      ];
+    })->initStorage(self::$storage)->build(self::DATA);
+    $count = 0;
+    foreach ($channel as $key => $item) {
+      msg::info("one: $key => {$item["a"]}");
+      $count++;
+    }
+    self::assertSame(3, $count);
+  }
+}
diff --git a/tests/cache/_TestCase.php b/tests/cache/_TestCase.php
new file mode 100644
index 0000000..f05875c
--- /dev/null
+++ b/tests/cache/_TestCase.php
@@ -0,0 +1,23 @@
+<?php
+namespace nulib\cache;
+
+use nulib\db\sqlite\SqliteStorage;
+use nulib\output\msg;
+use nulib\output\std\StdMessenger;
+use nulib\tests\TestCase;
+
+class _TestCase extends TestCase {
+  protected static SqliteStorage $storage;
+
+  static function setUpBeforeClass(): void {
+    parent::setUpBeforeClass();
+    msg::set_messenger_class(StdMessenger::class);
+    self::$storage = new SqliteStorage(__DIR__."/cache.db");
+    cache::set_storage(self::$storage);
+  }
+
+  static function tearDownAfterClass(): void {
+    parent::tearDownAfterClass();
+    self::$storage->close();
+  }
+}
diff --git a/tests/cache/cacheTest.php b/tests/cache/cacheTest.php
new file mode 100644
index 0000000..9d24daa
--- /dev/null
+++ b/tests/cache/cacheTest.php
@@ -0,0 +1,55 @@
+<?php
+namespace nulib\cache;
+
+use nulib\cl;
+use nulib\output\msg;
+
+class cacheTest extends _TestCase {
+  const DATA = [
+    "fr" => ["a" => "un", "b" => "deux"],
+    "eng" => ["a" => "one", "b" => "two"],
+    ["a" => 1, "b" => 2],
+  ];
+
+  function gendata() {
+    foreach (self::DATA as $key => $item) {
+      msg::info("yield $key");
+      yield $key => $item;
+      sleep(2);
+    }
+    msg::info("fin gendata");
+  }
+
+  function _testRows(iterable $rows) {
+    $count = 0;
+    foreach ($rows as $key => $row) {
+      msg::info("got $key => ".var_export($row, true));
+      $count++;
+    }
+    self::assertSame(3, $count);
+  }
+
+  function testUsage() {
+    msg::section("all");
+    $rows = cache::all($this->gendata(),"gendata");
+    $this->_testRows($rows);
+
+    msg::section("get");
+    $rows = cache::get(function() {
+      return self::DATA;
+    },"gendata");
+    $this->_testRows($rows);
+  }
+
+  function testNc() {
+    cache::nc();
+
+    msg::section("first pass");
+    $rows = cache::all($this->gendata(),"gendata");
+    $this->_testRows($rows);
+
+    msg::section("second pass");
+    $rows = cache::all($this->gendata(),"gendata");
+    $this->_testRows($rows);
+  }
+}