Let each workflow watch the due date or the start date

Deck 1.18 added a start date to cards (Card::$startdate), so a workflow
no longer has to mean "overdue". Each rule now carries a date_field
('due' | 'start'), chosen in the settings form next to board and stacks.

Existing rules keep the due date: the new column's default supplies it
for every stored row, so there is no backfill step, and
Workflow::getDateFieldOrDue() covers entities that were never near the
database as well as hand-edited values. The controller is the one place
that rejects an unknown value instead of normalising it - a client
asking for a rule it would not get should hear about it.

The probe for the field is property_exists(), not method_exists():
Deck's entities declare no getter as real code - getStartdate(),
getDuedate(), even getId() all go through Entity::__call(), which
method_exists() ignores by definition. A method_exists() guard would
have been false on every Deck version and would have turned every
start-date rule into a silent no-op.

assertDeckAvailable() now also refuses Deck older than 1.18.0. That
floor cannot live in appinfo/info.xml - neither the server's nor the app
store's schema has an app-to-app dependency element - but
<nextcloud min-version="34"> already implies it, since 1.18.x is the
only Deck release line published for Nextcloud 34.

isOverdue() becomes hasPassed(): one function for both dates, since the
comparison and the argument against Deck's day-truncating
getDaysUntilDue() are identical for either.

Also carries a pending NcSelect icon-alignment fix that was already in
the working tree.

Bump to 34.1.0.

lib/Controller/WorkflowController.php

@@ -56,14 +56,15 @@ class WorkflowController extends OCSController {
 		int $targetStackId,
 		array $filterUserIds = [],
 		array $filterLabelIds = [],
+		string $dateField = Workflow::DATE_FIELD_DUE,
 		bool $notifyEmail = false,
 		bool $enabled = true,
 	): DataResponse {
-		$this->validate($title, $boardId, $sourceStackId, $targetStackId);
+		$this->validate($title, $boardId, $sourceStackId, $targetStackId, $dateField);
 
 		$workflow = new Workflow();
 		$workflow->setUserId($this->currentUserId());
-		$this->applyFields($workflow, $title, $boardId, $sourceStackId, $targetStackId, $filterUserIds, $filterLabelIds, $notifyEmail, $enabled);
+		$this->applyFields($workflow, $title, $boardId, $sourceStackId, $targetStackId, $filterUserIds, $filterLabelIds, $dateField, $notifyEmail, $enabled);
 
 		$workflow = $this->workflowMapper->insert($workflow);
 		return new DataResponse($workflow->jsonSerialize(), Http::STATUS_CREATED);
@@ -82,10 +83,11 @@ class WorkflowController extends OCSController {
 		int $targetStackId,
 		array $filterUserIds = [],
 		array $filterLabelIds = [],
+		string $dateField = Workflow::DATE_FIELD_DUE,
 		bool $notifyEmail = false,
 		bool $enabled = true,
 	): DataResponse {
-		$this->validate($title, $boardId, $sourceStackId, $targetStackId);
+		$this->validate($title, $boardId, $sourceStackId, $targetStackId, $dateField);
 
 		try {
 			$workflow = $this->workflowMapper->findForUser($id, $this->currentUserId());
@@ -93,7 +95,7 @@ class WorkflowController extends OCSController {
 			throw new OCSNotFoundException('Workflow not found');
 		}
 
-		$this->applyFields($workflow, $title, $boardId, $sourceStackId, $targetStackId, $filterUserIds, $filterLabelIds, $notifyEmail, $enabled);
+		$this->applyFields($workflow, $title, $boardId, $sourceStackId, $targetStackId, $filterUserIds, $filterLabelIds, $dateField, $notifyEmail, $enabled);
 		$workflow = $this->workflowMapper->update($workflow);
 
 		return new DataResponse($workflow->jsonSerialize());
@@ -147,13 +149,19 @@ class WorkflowController extends OCSController {
 		}
 	}
 
-	private function validate(string $title, int $boardId, int $sourceStackId, int $targetStackId): void {
+	private function validate(string $title, int $boardId, int $sourceStackId, int $targetStackId, string $dateField): void {
 		if (trim($title) === '') {
 			throw new OCSBadRequestException('Title must not be empty');
 		}
 		if ($sourceStackId === $targetStackId) {
 			throw new OCSBadRequestException('Source and target stack must differ');
 		}
+		// Rejected rather than silently normalised to 'due': a client sending
+		// something else is asking for a rule it would not get, and the runner
+		// falls back to the due date without a word.
+		if (!in_array($dateField, Workflow::DATE_FIELDS, true)) {
+			throw new OCSBadRequestException('Unknown date field: ' . $dateField);
+		}
 
 		// Reject references to boards or stacks that are gone (or were never
 		// the user's) instead of storing a workflow that can only fail later.
@@ -190,6 +198,7 @@ class WorkflowController extends OCSController {
 		int $targetStackId,
 		array $filterUserIds,
 		array $filterLabelIds,
+		string $dateField,
 		bool $notifyEmail,
 		bool $enabled,
 	): void {
@@ -199,6 +208,7 @@ class WorkflowController extends OCSController {
 		$workflow->setTargetStackId($targetStackId);
 		$workflow->setFilterUserIds($filterUserIds === [] ? null : json_encode(array_values($filterUserIds)));
 		$workflow->setFilterLabelIds($filterLabelIds === [] ? null : json_encode(array_values($filterLabelIds)));
+		$workflow->setDateField($dateField);
 		$workflow->setNotifyEmail($notifyEmail);
 		$workflow->setEnabled($enabled);
 	}

lib/Db/Workflow.php

@@ -22,6 +22,8 @@ use OCP\DB\Types;
  * @method void setFilterUserIds(?string $filterUserIds)
  * @method string|null getFilterLabelIds()
  * @method void setFilterLabelIds(?string $filterLabelIds)
+ * @method string|null getDateField()
+ * @method void setDateField(string $dateField)
  * @method bool getNotifyEmail()
  * @method void setNotifyEmail(bool $notifyEmail)
  * @method bool getEnabled()
@@ -30,6 +32,14 @@ use OCP\DB\Types;
  * @method void setLastRun(?\DateTime $lastRun)
  */
 class Workflow extends Entity implements \JsonSerializable {
+	/** Deck's `Card::$duedate` — the card is picked up once it is overdue. */
+	public const DATE_FIELD_DUE = 'due';
+
+	/** Deck's `Card::$startdate` — the card is picked up once its start date has been reached. */
+	public const DATE_FIELD_START = 'start';
+
+	public const DATE_FIELDS = [self::DATE_FIELD_DUE, self::DATE_FIELD_START];
+
 	protected $userId;
 	protected $title;
 	protected $boardId;
@@ -37,6 +47,7 @@ class Workflow extends Entity implements \JsonSerializable {
 	protected $targetStackId;
 	protected $filterUserIds;
 	protected $filterLabelIds;
+	protected $dateField;
 	protected $notifyEmail;
 	protected $enabled;
 	protected $lastRun;
@@ -50,11 +61,29 @@ class Workflow extends Entity implements \JsonSerializable {
 		$this->addType('targetStackId', Types::INTEGER);
 		$this->addType('filterUserIds', Types::STRING);
 		$this->addType('filterLabelIds', Types::STRING);
+		$this->addType('dateField', Types::STRING);
 		$this->addType('notifyEmail', Types::BOOLEAN);
 		$this->addType('enabled', Types::BOOLEAN);
 		$this->addType('lastRun', Types::DATETIME);
 	}
 
+	/**
+	 * The date field to evaluate, never anything else.
+	 *
+	 * Rows written before the column existed carry 'due' from the schema
+	 * default, but a freshly constructed entity holds `null` and a hand-edited
+	 * row could hold anything. Falling back to the due date keeps the old
+	 * behaviour for every value that is not explicitly the start date — the
+	 * safe direction, since 'due' is what every workflow meant before this
+	 * choice existed.
+	 *
+	 * @return self::DATE_FIELD_*
+	 */
+	public function getDateFieldOrDue(): string {
+		$field = $this->getDateField();
+		return in_array($field, self::DATE_FIELDS, true) ? $field : self::DATE_FIELD_DUE;
+	}
+
 	/**
 	 * @return string[]
 	 */
@@ -90,6 +119,7 @@ class Workflow extends Entity implements \JsonSerializable {
 			'targetStackId' => $this->getTargetStackId(),
 			'filterUserIds' => $this->getFilterUserIdsArray(),
 			'filterLabelIds' => $this->getFilterLabelIdsArray(),
+			'dateField' => $this->getDateFieldOrDue(),
 			'notifyEmail' => (bool)$this->getNotifyEmail(),
 			'enabled' => (bool)$this->getEnabled(),
 			'lastRun' => $this->getLastRun()?->format(\DateTimeInterface::ATOM),

lib/Migration/Version1001Date20260825120000.php

@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OCA\WorkflowDeckAutomation\Migration;
+
+use Closure;
+use OCA\WorkflowDeckAutomation\Db\Workflow;
+use OCP\DB\ISchemaWrapper;
+use OCP\DB\Types;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+/**
+ * Adds the per-workflow choice between Deck's due date and its start date.
+ *
+ * A separate migration rather than an edit to Version1000...: that one is
+ * wrapped in `if (!$schema->hasTable(...))`, so changing it would only ever
+ * reach fresh installs.
+ *
+ * The `default` is what migrates the existing rows — every workflow written
+ * before this release was evaluated against the due date, and the column
+ * default gives exactly that without a backfill step.
+ */
+class Version1001Date20260825120000 extends SimpleMigrationStep {
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		if (!$schema->hasTable('wfda_workflows')) {
+			return null;
+		}
+
+		$table = $schema->getTable('wfda_workflows');
+		if ($table->hasColumn('date_field')) {
+			return null;
+		}
+
+		$table->addColumn('date_field', Types::STRING, [
+			'notnull' => true,
+			'length' => 16,
+			'default' => Workflow::DATE_FIELD_DUE,
+		]);
+
+		return $schema;
+	}
+}

lib/Service/DeckIntegrationService.php

@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace OCA\WorkflowDeckAutomation\Service;
 
+use DateTimeInterface;
 use OCA\Deck\Db\BoardMapper;
 use OCA\Deck\Db\Card;
 use OCA\Deck\Db\CardMapper;
@@ -35,6 +36,25 @@ use Throwable;
 class DeckIntegrationService {
 	private const DECK_APP_ID = 'deck';
 
+	/**
+	 * Oldest Deck this app will talk to.
+	 *
+	 * Deck 1.18.0 is the release that added the card start date
+	 * (`Card::$startdate`, PR #7749), which the start-date workflows read.
+	 * The floor cannot live in appinfo/info.xml: neither the server's
+	 * app-info.xsd nor the app store's info.xsd has an app-to-app dependency
+	 * element, only <nextcloud>.
+	 *
+	 * That pin does most of the work anyway — Deck 1.18.x is the only release
+	 * line declaring `>=34.0.0,<35.0.0`, so on the Nextcloud 34 this app
+	 * requires, every installable Deck already carries the field. What is left
+	 * for this check is a Deck put in place by hand or from git.
+	 *
+	 * version_compare() sorts `1.18.0-beta.x` *below* `1.18.0`, and that is
+	 * intended: the betas of that line may predate the field.
+	 */
+	private const MIN_DECK_VERSION = '1.18.0';
+
 	/**
 	 * Deck's Acl::PERMISSION_TYPE_* values, inlined so this class keeps
 	 * working (degrading to "treat it as a user") if Deck ever moves or
@@ -68,11 +88,31 @@ class DeckIntegrationService {
 		'OCA\Deck\Activity\ActivityManager',
 	];
 
+	/**
+	 * `Workflow::DATE_FIELD_*` mapped to the property on Deck's Card entity.
+	 * Kept here rather than on the Workflow so this class stays the only one
+	 * that has to know what Deck calls its columns.
+	 */
+	private const CARD_DATE_PROPERTIES = [
+		'due' => 'duedate',
+		'start' => 'startdate',
+	];
+
+	private const DEFAULT_CARD_DATE = 'due';
+
 	/**
 	 * @var list<array{ReflectionProperty, object, ?string}>
 	 */
 	private array $identityRestore = [];
 
+	/**
+	 * Card properties already reported as missing, so the warning in
+	 * getCardDate() is one line per process instead of one per card.
+	 *
+	 * @var array<string, true>
+	 */
+	private array $reportedMissingCardProperties = [];
+
 	public function __construct(
 		private IAppManager $appManager,
 		private IUserManager $userManager,
@@ -166,6 +206,16 @@ class DeckIntegrationService {
 		if (!$this->appManager->isEnabledForUser(self::DECK_APP_ID, $user)) {
 			throw new DeckUnavailableException('Deck is not enabled for user ' . $user->getUID());
 		}
+
+		$version = $this->appManager->getAppVersion(self::DECK_APP_ID);
+		if ($version === '' || version_compare($version, self::MIN_DECK_VERSION, '<')) {
+			throw new DeckUnavailableException(sprintf(
+				'Deck %s is installed, but %s or newer is required',
+				$version !== '' ? $version : '(unknown version)',
+				self::MIN_DECK_VERSION,
+			));
+		}
+
 		if (!class_exists(CardService::class) || !class_exists(BoardService::class) || !class_exists(StackService::class)) {
 			throw new DeckUnavailableException('Deck internal classes are not available');
 		}
@@ -487,7 +537,7 @@ class DeckIntegrationService {
 			// *returns* CardDetails wrappers whose own fields (duedate, stackId, ...) were never
 			// copied from the wrapped card - only its overridden jsonSerialize() reads through to
 			// them. Capturing that return value here made every card's getDuedate()/getDaysUntilDue()
-			// resolve to null, so isOverdue() was always false and no workflow ever matched a card.
+			// resolve to null, so hasPassed() was always false and no workflow ever matched a card.
 			// Keep using the original, now-enriched $cards instead.
 			$cardService->enrichCards($cards);
 
@@ -500,6 +550,45 @@ class DeckIntegrationService {
 		}, []);
 	}
 
+	/**
+	 * The card date a workflow is evaluated against: Deck's due date or its
+	 * start date, per `Workflow::DATE_FIELD_*`. Anything unrecognised reads the
+	 * due date, which is what every workflow meant before the choice existed.
+	 *
+	 * The guard is `property_exists()`, deliberately, and this is the one thing
+	 * to get right here: **`method_exists()` cannot see Deck's getters.**
+	 * `Card`, `Board`, `Label`, `Acl` and `Assignment` declare none of them as
+	 * real code — `getStartdate()`, `getDuedate()`, even `getId()` all go
+	 * through `OCP\AppFramework\Db\Entity::__call()`, and `method_exists()`
+	 * ignores `__call()` by definition. A `method_exists($card, 'getStartdate')`
+	 * probe would therefore be false on *every* Deck version and silently turn
+	 * every start-date workflow into a no-op. `property_exists()` sees the
+	 * protected `$startdate` declaration and is exactly what `Entity::getter()`
+	 * checks internally before throwing.
+	 *
+	 * In practice the property is always there — `assertDeckAvailable()`
+	 * enforces Deck >= MIN_DECK_VERSION, which is the release that added it —
+	 * so this branch is a backstop for a hand-installed Deck, loud enough to be
+	 * found in the log rather than silently matching nothing.
+	 */
+	public function getCardDate(Card $card, string $dateField): ?DateTimeInterface {
+		$property = self::CARD_DATE_PROPERTIES[$dateField] ?? self::CARD_DATE_PROPERTIES[self::DEFAULT_CARD_DATE];
+
+		if (!property_exists($card, $property)) {
+			if (!isset($this->reportedMissingCardProperties[$property])) {
+				$this->reportedMissingCardProperties[$property] = true;
+				$this->logger->warning(
+					'This Deck version has no Card::$' . $property . '; workflows using it cannot match any card',
+					['app' => 'workflow_deck_automation'],
+				);
+			}
+			return null;
+		}
+
+		$value = $property === 'startdate' ? $card->getStartdate() : $card->getDuedate();
+		return $value instanceof DateTimeInterface ? $value : null;
+	}
+
 	/**
 	 * @return string[]
 	 */

lib/Service/NotificationMailer.php

@@ -55,10 +55,19 @@ class NotificationMailer {
 			$template->setSubject($this->l10n->t('Deck card moved: %s', [$card->getTitle()]));
 			$template->addHeader();
 			$template->addHeading($this->l10n->t('A card was moved automatically'), false);
-			$template->addBodyText($this->l10n->t(
-				'The card "%1$s" was moved because it is overdue (workflow "%2$s").',
-				[$card->getTitle(), $workflow->getTitle()],
-			));
+			// Two whole strings rather than one sentence with an interpolated
+			// reason: the trigger is the point of the mail, and a translator
+			// needs to see it in the sentence to get the grammar right.
+			$reason = $workflow->getDateFieldOrDue() === Workflow::DATE_FIELD_START
+				? $this->l10n->t(
+					'The card "%1$s" was moved because its start date has been reached (workflow "%2$s").',
+					[$card->getTitle(), $workflow->getTitle()],
+				)
+				: $this->l10n->t(
+					'The card "%1$s" was moved because it is overdue (workflow "%2$s").',
+					[$card->getTitle(), $workflow->getTitle()],
+				);
+			$template->addBodyText($reason);
 			// Single-argument addBodyText() runs htmlspecialchars() itself, so
 			// these board- and stack-titles (user input) are safe as-is —
 			// unlike the description below, which passes both parts.

lib/Service/WorkflowRunner.php

@@ -17,7 +17,8 @@ use Psr\Log\LoggerInterface;
 use Throwable;
 
 /**
- * Evaluates all enabled workflows and moves overdue cards.
+ * Evaluates all enabled workflows and moves the cards whose watched date -
+ * Deck's due date or its start date, per workflow - has passed.
  *
  * This runner has to evaluate rules for many different users within a
  * single background-job process, so workflows are grouped by owner and
@@ -167,9 +168,10 @@ class WorkflowRunner {
 		$targets = null;
 
 		$now = $this->timeFactory->getDateTime();
+		$dateField = $workflow->getDateFieldOrDue();
 
 		foreach ($cards as $card) {
-			if (!self::isOverdue($card->getDuedate(), $now)) {
+			if (!self::hasPassed($this->deckService->getCardDate($card, $dateField), $now)) {
 				continue;
 			}
 
@@ -179,11 +181,12 @@ class WorkflowRunner {
 				continue;
 			}
 
-			$this->logger->info('Card {card} ("{title}") matches workflow {id}; moving to stack {target}.', [
+			$this->logger->info('Card {card} ("{title}") matches workflow {id} on its {dateField} date; moving to stack {target}.', [
 				'app' => 'workflow_deck_automation',
 				'card' => $card->getId(),
 				'title' => $card->getTitle(),
 				'id' => $workflow->getId(),
+				'dateField' => $dateField,
 				'target' => $workflow->getTargetStackId(),
 			]);
 
@@ -323,16 +326,21 @@ class WorkflowRunner {
 	}
 
 	/**
-	 * Compares the card's actual due timestamp against $now instead of Deck's own
+	 * Whether the card date a workflow watches - its due date or its start date,
+	 * see Workflow::DATE_FIELD_* - lies in the past. A card without that date set
+	 * is never picked up.
+	 *
+	 * Compares the card's actual timestamp against $now instead of Deck's own
 	 * Card::getDaysUntilDue(), which truncates both sides to midnight before diffing
 	 * (DateInterval's %a is a whole-day count) and therefore reports 0 - not overdue -
 	 * for any card whose due time has already passed today. That silently held back
 	 * every card for up to 24h after it actually fell due; comparing the raw datetime
 	 * instead matches what Deck's own UI shows (e.g. "vor 2 Stunden") and has no
-	 * day-rounding step to get wrong.
+	 * day-rounding step to get wrong. The same reasoning applies unchanged to the
+	 * start date, which is why this is one function and not two.
 	 */
-	public static function isOverdue(?DateTimeInterface $duedate, DateTimeInterface $now): bool {
-		return $duedate !== null && $duedate < $now;
+	public static function hasPassed(?DateTimeInterface $cardDate, DateTimeInterface $now): bool {
+		return $cardDate !== null && $cardDate < $now;
 	}
 
 	/**