fix #32: allow filtering student projects by repository

entities/ProjGroup.php

@@ -112,6 +112,11 @@ public function getRepository() : ?Repository {
     return $this->repository ? new Repository($this->repository) : null;
   }
 
+  public function getRepositoryId() : string {
+    $repo = $this->getRepository();
+    return $repo ? $repo->id : '';
+  }
+
   public function getValidRepository() : ?Repository {
     $repo = $this->getRepository();
     return $repo && $repo->isValid() ? $repo : null;

pages/listprojects.php

@@ -9,6 +9,7 @@
 $selected_shift
   = isset($_POST['shift']) ? db_fetch_shift_id($_POST['shift']) : null;
 $own_shifts_only = !empty($_POST['own_shifts']);
+$selected_repo = $_POST['repo'] ?? 'all';
 
 echo <<<EOF
 <form action="index.php?page=listprojects" method="post">
@@ -50,14 +51,42 @@
        "</option>\n";
 }
 
-echo <<<EOF
-</select>
-</form>
+echo "</select>\n";
+
+$groups = db_fetch_groups($selected_year);
+
+if (auth_at_least(ROLE_PROF)) {
+  echo <<<EOF
+<br>
+<label for="repo">Filter by repository:</label>
+<select name="repo" id="repo" onchange='this.form.submit()'>
+<option value="all">All</option>
 EOF;
 
+  $repos = [];
+  foreach ($groups as $group) {
+    if (!has_group_permissions($group))
+      continue;
+
+    if ($repo = $group->getRepositoryId())
+      $repos[$repo] = true;
+  }
+  $repos = array_keys($repos);
+  natsort($repos);
+
+  foreach ($repos as $repo) {
+    $select = $repo == $selected_repo ? ' selected' : '';
+    echo "<option value=\"$repo\"$select>", htmlspecialchars($repo),
+         "</option>\n";
+  }
+  echo "</select>\n";
+}
+
+echo "</form>\n";
+
 echo "<p>Groups:</p>\n";
 $table = [];
-foreach (db_fetch_groups($selected_year) as $group) {
+foreach ($groups as $group) {
   if (!has_group_permissions($group))
     continue;
 
@@ -67,6 +96,9 @@
   if ($own_shifts_only && $group->prof() != get_user())
     continue;
 
+  if ($selected_repo != 'all' && $group->getRepositoryId() != $selected_repo)
+    continue;
+
   $students = [];
   foreach ($group->students as $s) {
     $students[] = "$s->name ($s->id)";