diff --git a/src/inc/listings.php b/src/inc/listings.php
new file mode 100644
index 0000000..b3aa258
--- /dev/null
+++ b/src/inc/listings.php
@@ -0,0 +1,102 @@
+<?php
+class listings {
+  public static function renderFilterDialog($form, $select) {
+    global $_GET;
+    ?>
+    <dialog class="mdl-dialog" id="filter">
+      <form action="<?=$form?>" method="GET" enctype="multipart/form-data">
+        <h4 class="mdl-dialog__title">Filtrar lista</h4>
+        <div class="mdl-dialog__content">
+          <h5>Categorías</h5>
+          <label class="mdl-checkbox mdl-js-checkbox mdl-js-ripple-effect" for="cat-1">
+            <input type="checkbox" id="cat-1" name="categories[-1]" class="mdl-checkbox__input" value="1"<?=(($select["enabled"]["categories"] && in_array(-1, $select["selected"]["categories"])) ? " checked" : "")?>>
+            <span class="mdl-checkbox__label">Sin categoría</span>
+          </label>
+          <?php
+          foreach (categories::getAll(false, false, true) as $c) {
+            $haschilds = (count($c["childs"]) > 0);
+            if ($haschilds) {
+              $subcategories_arr = [];
+              foreach ($c["childs"] as $child) {
+                $subcategories_arr[] = "&ldquo;".security::htmlsafe($child["name"])."&rdquo;";
+              }
+              $subcategories = implode(", ", $subcategories_arr);
+            }
+            ?>
+            <label class="mdl-checkbox mdl-js-checkbox mdl-js-ripple-effect" for="cat<?=(int)$c["id"]?>">
+              <input type="checkbox" id="cat<?=(int)$c["id"]?>" name="categories[<?=(int)$c["id"]?>]" class="mdl-checkbox__input" value="1"<?=(($select["enabled"]["categories"] && in_array($c["id"], $select["selected"]["categories"])) ? " checked" : "")?>>
+              <span class="mdl-checkbox__label"><?=security::htmlsafe($c["name"])?> <?php if ($haschilds) { ?><i id="haschilds<?=(int)$c["id"]?>" class="material-icons help">info</i><?php } ?></span>
+            </label>
+            <?php
+            if ($haschilds) {
+              ?>
+              <div class="mdl-tooltip" for="haschilds<?=(int)$c["id"]?>">Esta categoría incluye la<?=(count($c["childs"]) == 1 ? "" : "s")?> subcategoría<?=(count($c["childs"]) == 1 ? "" : "s")?> <?=$subcategories?></div>
+              <?php
+            }
+          }
+          ?>
+          <h5>Empresas</h5>
+          <?php
+          foreach (companies::getAll() as $id => $company) {
+            ?>
+            <label class="mdl-checkbox mdl-js-checkbox mdl-js-ripple-effect" for="comp<?=(int)$id?>">
+              <input type="checkbox" id="comp<?=(int)$id?>" name="companies[<?=(int)$id?>]" class="mdl-checkbox__input" value="1"<?=(($select["enabled"]["companies"] && in_array($id, $select["selected"]["companies"])) ? " checked" : "")?>>
+              <span class="mdl-checkbox__label"><?=security::htmlsafe($company)?></span>
+            </label>
+            <?php
+          }
+          ?>
+          <h5>Tipos de usuario</h5>
+          <?php
+          foreach (security::$types as $id => $type) {
+            ?>
+            <label class="mdl-checkbox mdl-js-checkbox mdl-js-ripple-effect" for="type<?=(int)$id?>">
+              <input type="checkbox" id="type<?=(int)$id?>" name="types[<?=(int)$id?>]" class="mdl-checkbox__input" value="1"<?=(($select["enabled"]["types"] && in_array($id, $select["selected"]["types"])) ? " checked" : "")?>>
+              <span class="mdl-checkbox__label"><?=security::htmlsafe($type)?></span>
+            </label>
+            <?php
+          }
+
+          if ($form == "workers.php") {
+            echo "<h5>Horario actual</h5>";
+            foreach (schedules::$workerScheduleStatusShort as $id => $type) {
+              ?>
+              <label class="mdl-checkbox mdl-js-checkbox mdl-js-ripple-effect" for="schedulesstatus<?=(int)$id?>">
+                <input type="checkbox" id="schedulesstatus<?=(int)$id?>" name="schedulesstatus[<?=(int)$id?>]" class="mdl-checkbox__input" value="1"<?=(isset($_GET["schedulesstatus"][(int)$id]) ? " checked" : "")?>>
+                <span class="mdl-checkbox__label mdl-color-text--<?=security::htmlsafe(schedules::$workerScheduleStatusColors[$id])?>"><?=security::htmlsafe($type)?></span>
+              </label>
+              <?php
+            }
+          }
+          ?>
+        </div>
+        <div class="mdl-dialog__actions">
+          <button type="submit" class="mdl-button mdl-js-button mdl-js-ripple-effect mdl-button--accent">Filtrar</button>
+          <button onclick="event.preventDefault(); document.querySelector('#filter').close();" class="mdl-button mdl-js-button mdl-js-ripple-effect cancel">Cancelar</button>
+        </div>
+      </form>
+    </dialog>
+    <?php
+  }
+
+  public static function buildSelect($form) {
+    global $select, $selectedSchedulesStatus, $_GET;
+
+    $select = array("enabled" => [], "selected" => []);
+
+    foreach (people::$filters as $f) {
+      $select["enabled"][$f] = isset($_GET[$f]);
+      if ($select["enabled"][$f]) {
+        $select["selected"][$f] = (isset($_GET[$f]) ? array_keys($_GET[$f]) : []);
+      }
+    }
+
+    if ($form == "workers.php") {
+      if (isset($_GET["schedulesstatus"]) && is_array($_GET["schedulesstatus"]) && count($_GET["schedulesstatus"])) {
+        $selectedSchedulesStatus = array_keys($_GET["schedulesstatus"]);
+      } else {
+        $selectedSchedulesStatus = false;
+      }
+    }
+  }
+}