Addresses table registration and scheduling issues

CHANGELOG.md

@@ -2,6 +2,17 @@
 
 All notable changes to this project will be documented in this file. This project adhere to the [Semantic Versioning](http://semver.org/) standard.
 
+## [0.0.7] 2025-09-08
+
+* Fix - Ensure the regulator is registered only when the tables are created/updated successfully.
+* Fix - When scheduling an action, return 0 if the action ID is not an integer.
+* Fix - Fix fetch_all Custom_Table_Query_Methods batch generator by properly incrementing the offset.
+* Tweak - Update the schema version of the Tasks table to 0.0.3 to fix a typo in the version string.
+* Tweak - Update the get_pending_actions_by_ids method to also exclude null actions.
+* Tweak - Use the hook `action_scheduler_init` to determine if Action Scheduler is initialized instead of the `init` hook.
+
+[0.0.7]: https://github.com/stellarwp/shepherd/releases/tag/0.0.7
+
 ## [0.0.6] 2025-08-26
 
 * Fix - Update Email task to properly handle multiple email recipients separated by commas.

docs/advanced-usage.md

@@ -97,6 +97,67 @@ When dispatching a duplicate task:
 
 Prevents accidental duplication and is enabled by default.
 
+## Task Dispatching Requirements (Since 0.0.7)
+
+When dispatching tasks, Shepherd performs several checks:
+
+1. **Table Registration**: Verifies that Shepherd's database tables are registered
+2. **Action Scheduler**: Ensures Action Scheduler is initialized
+
+### Synchronous Fallback When Tables Not Registered
+
+If Shepherd's database tables are not yet registered when you dispatch a task, by default the task will be **processed immediately in a synchronous manner** instead of being queued for background processing. This ensures tasks can still execute even during early initialization phases.
+
+```php
+// If tables are not registered, this task will run immediately
+shepherd()->dispatch( new My_Task() );
+```
+
+You can monitor when this synchronous processing occurs:
+
+```php
+$prefix = Config::get_hook_prefix();
+
+add_action( "shepherd_{$prefix}_dispatched_sync", function( $task ) {
+    error_log( 'Task processed synchronously: ' . get_class( $task ) );
+});
+```
+
+#### Disabling Synchronous Fallback
+
+If you prefer tasks to be skipped rather than processed synchronously when tables are unavailable or handle their scheduling yourself:
+
+```php
+add_filter( "shepherd_{$prefix}_should_dispatch_sync_on_tables_unavailable", function( $should_dispatch, Task $task ) {
+    // Return false to skip task processing when tables are not ready
+    return false;
+}, 10, 2 );
+```
+
+### Action Scheduler Initialization
+
+If Action Scheduler is not yet initialized when you dispatch a task, Shepherd will automatically queue it and dispatch once Action Scheduler is ready via the `action_scheduler_init` hook.
+
+### Handling Table Registration Errors (Since 0.0.7)
+
+Your application should handle cases where Shepherd's tables fail to register by listening to the `shepherd_{prefix}_tables_error` action:
+
+```php
+$prefix = Config::get_hook_prefix();
+
+add_action( "shepherd_{$prefix}_tables_error", function( $error ) {
+    // Log the error
+    error_log( 'Shepherd tables failed to register: ' . $error->getMessage() );
+
+    // Notify administrators
+    add_action( 'admin_notices', function() use ( $error ) {
+        echo '<div class="notice notice-error"><p>' . esc_html__( 'Background processing is unavailable. Please contact support.', 'stellarwp-shepherd' ) . '</p></div>';
+    } );
+});
+```
+
+If this action is not handled, Shepherd will trigger a `_doing_it_wrong` notice to alert developers during development.
+
 ## Logging
 
 Comprehensive logging tracks the complete task lifecycle.

docs/api-reference.md

@@ -18,15 +18,21 @@ The main orchestrator for task scheduling and processing.
 
 #### Methods
 
-##### `dispatch( Task $task, int $delay = 0 ): void`
+##### `dispatch( Task $task, int $delay = 0 ): self`
 
 Schedules a task for execution.
 
 - **Parameters:**
   - `$task` - The task instance to schedule
   - `$delay` - Delay in seconds before execution (default: 0)
+- **Returns:** The Regulator instance for method chaining
 - **Throws:** and **Catches:** `ShepherdTaskAlreadyExistsException` if duplicate task exists
 - **Throws:** and **Catches:** `RuntimeException` if task fails to be scheduled or inserted into the database.
+- **Since 0.0.7 - Synchronous Fallback:** When Shepherd tables are not registered:
+  - Tasks are processed immediately in a synchronous manner by default
+  - Fires `shepherd_{prefix}_dispatched_sync` action when processing synchronously
+  - Can be disabled via `shepherd_{prefix}_should_dispatch_sync_on_tables_unavailable` filter
+- **Hook Integration:** As of version 0.0.7, uses `action_scheduler_init` hook instead of `init` to ensure Action Scheduler is ready.
 - You can listen for those errors above, by listening to the following actions:
   - `shepherd_{prefix}_task_scheduling_failed`
   - `shepherd_{prefix}_task_already_exists`
@@ -106,6 +112,8 @@ Service provider for dependency injection and initialization.
 
 Initializes Shepherd and registers all components.
 
+- **Since version 0.0.7:** The Regulator is only registered after tables are successfully created/updated via the `shepherd_{prefix}_tables_registered` action.
+
 ##### `set_container( ContainerInterface $container ): void`
 
 Sets the dependency injection container.
@@ -118,6 +126,19 @@ Returns the container instance.
 
 Checks if Shepherd has been registered.
 
+##### `register_regulator(): void`
+
+Registers the Regulator component to start processing tasks.
+
+- **Since:** 0.0.7
+- **Visibility:** Public
+- **Purpose:** Separated from the main registration flow to allow for conditional registration
+- **Behavior:**
+  - Retrieves the Regulator instance from the DI container
+  - Calls the Regulator's `register()` method to initialize task processing
+- **Hook:** Automatically called on `shepherd_{prefix}_tables_registered` action
+- **Usage:** Can be manually removed from the action hook if custom registration timing is needed
+
 ##### `delete_tasks_on_action_deletion( int $action_id ): void`
 
 Automatically removes task data when Action Scheduler deletes an action.
@@ -133,6 +154,64 @@ Automatically removes task data when Action Scheduler deletes an action.
 
 ---
 
+### `Action_Scheduler_Methods`
+
+Wrapper class for Action Scheduler integration (since 0.0.1).
+
+#### Methods
+
+##### `has_scheduled_action( string $hook, array $args = [], string $group = '' ): bool`
+
+Checks if an action is scheduled.
+
+- **Parameters:**
+  - `$hook` - The hook of the action
+  - `$args` - The arguments of the action
+  - `$group` - The group of the action
+- **Returns:** Whether the action is scheduled
+
+##### `schedule_single_action( int $timestamp, string $hook, array $args = [], string $group = '', bool $unique = false, int $priority = 10 ): int`
+
+Schedules a single action.
+
+- **Parameters:**
+  - `$timestamp` - The timestamp when the action should run
+  - `$hook` - The hook of the action
+  - `$args` - The arguments of the action
+  - `$group` - The group of the action
+  - `$unique` - Whether the action should be unique
+  - `$priority` - The priority of the action (0-255)
+- **Returns:** The action ID, or 0 if scheduling failed (since 0.0.7)
+
+##### `get_action_by_id( int $action_id ): ActionScheduler_Action`
+
+Gets an action by its ID.
+
+- **Parameters:**
+  - `$action_id` - The action ID
+- **Returns:** The action object
+- **Throws:** `RuntimeException` if the action is not found
+
+##### `get_actions_by_ids( array $action_ids ): array`
+
+Gets multiple actions by their IDs.
+
+- **Parameters:**
+  - `$action_ids` - Array of action IDs
+- **Returns:** Array of ActionScheduler_Action objects keyed by ID
+- **Throws:** `RuntimeException` if any action is not found
+
+##### `get_pending_actions_by_ids( array $action_ids ): array`
+
+Gets pending actions by their IDs, excluding finished and null actions.
+
+- **Parameters:**
+  - `$action_ids` - Array of action IDs
+- **Returns:** Array of pending ActionScheduler_Action objects
+- **Since 0.0.7:** Also excludes `ActionScheduler_NullAction` instances
+
+---
+
 ### `Email` Task
 
 Built-in task for sending emails asynchronously.
@@ -416,6 +495,13 @@ Table name: `shepherd_{prefix}_task_logs`
 
 ### Actions
 
+- `shepherd_{prefix}_tables_registered` - Fired when Shepherd tables are successfully registered (since 0.0.7)
+  - No parameters
+  - Used internally to ensure safe initialization of the Regulator
+
+- `shepherd_{prefix}_tables_error` - Fired when database table creation/update fails (since 0.0.7)
+  - Parameters: `$exception` (DatabaseQueryException)
+
 - `shepherd_{prefix}_task_scheduling_failed` - Fired when a task fails to be scheduled
   - Parameters: `$task`, `$exception`
 
@@ -442,4 +528,6 @@ Table name: `shepherd_{prefix}_task_logs`
 
 ### Filters
 
-Currently, Shepherd does not provide any filters.
+- `shepherd_{prefix}_should_log` - Filter to control whether logging should occur (since 0.0.5)
+  - Parameters: `$should_log` (bool, default: true)
+  - Return false to disable logging

docs/configuration.md

@@ -115,10 +115,22 @@ The tasks table is created automatically when you call `Provider::register()`.
 
 The logs table is only created if you're using the `DB_Logger`. When using the default `ActionScheduler_DB_Logger`, logs are stored in Action Scheduler's existing `actionscheduler_logs` table.
 
+**Since version 0.0.7:**
+
+- Tables are created/updated before the Regulator is initialized
+- The `shepherd_{prefix}_tables_registered` action is fired upon successful table registration
+- The `shepherd_{prefix}_tables_error` action is fired if table creation fails
+- The Regulator will only be registered after tables are successfully created
+
 ## Action Scheduler Configuration
 
 Shepherd uses Action Scheduler for task scheduling. You can configure Action Scheduler settings separately:
 
+**Since version 0.0.7:**
+
+- Shepherd now uses the `action_scheduler_init` hook to ensure Action Scheduler is ready before dispatching tasks
+- Tasks dispatched before Action Scheduler initialization are automatically queued and dispatched once it's ready
+
 ### Custom Action Scheduler Tables
 
 Action Scheduler uses its own tables. If you need custom table names, configure Action Scheduler before loading Shepherd.
@@ -161,6 +173,7 @@ $container->get( Provider::class )->register();
 2. **Use Consistent Prefixes**: Keep your hook prefix consistent across your application
 3. **Container Singleton**: Always register Provider as a singleton
 4. **Check Registration**: If you are not sure whether Shepherd is registered, you can check it using `Provider::is_registered()` before accessing Shepherd
+5. **Table Initialization** (since 0.0.7): Listen to `shepherd_{prefix}_tables_registered` if you need to perform actions after tables are ready
 
 ```php
 if ( ! Provider::is_registered() ) {

docs/getting-started.md

@@ -138,11 +138,12 @@ shepherd()->dispatch( $my_task, 5 * MINUTE_IN_SECONDS ); // Execute after 5 minu
 
 ### What Happens Next?
 
-1. Shepherd schedules your task with Action Scheduler
-2. WordPress cron picks up the task
-3. Your task's `process()` method executes
-4. The lifecycle is logged in the database
-5. Failed tasks may be retried based on configuration
+1. Shepherd validates that its tables are registered (since 0.0.7)
+2. Shepherd schedules your task with Action Scheduler
+3. WordPress cron picks up the task
+4. Your task's `process()` method executes
+5. The lifecycle is logged in the database
+6. Failed tasks may be retried based on configuration
 
 Check `debug.log` for the message "Shepherd Task: Hello, World! with code 200".
 
@@ -176,3 +177,5 @@ If your tasks aren't running:
 2. **Verify WP-Cron**: Ensure WordPress cron is running or set up a real cron job
 3. **Check Logs**: Look for errors in your WordPress debug log
 4. **Database Tables**: Ensure Shepherd's tables were created during registration
+5. **Table Registration** (since 0.0.7): Check for `shepherd_{prefix}_tables_error` action if tables fail to create
+6. **Initialization Order** (since 0.0.7): Ensure Action Scheduler is loaded before dispatching tasks

shepherd.php

@@ -9,7 +9,7 @@
  * @wordpress-plugin
  * Plugin Name: Shepherd
  * Description: A library for offloading tasks to background processes.
- * Version:     0.0.6
+ * Version:     0.0.7
  * Author:      StellarWP
  * Author URI:  https://stellarwp.com
  * License:     GPL-2.0-or-later

src/Action_Scheduler_Methods.php

@@ -14,6 +14,7 @@
 use ActionScheduler;
 use ActionScheduler_Action;
 use ActionScheduler_FinishedAction;
+use ActionScheduler_NullAction;
 use RuntimeException;
 
 /**
@@ -43,6 +44,7 @@ public static function has_scheduled_action( string $hook, array $args = [], str
 	 * Schedules a single action.
 	 *
 	 * @since 0.0.1
+	 * @since 0.0.7 Updated to return 0 if the action ID is not an integer.
 	 *
 	 * @param int    $timestamp The timestamp of the action.
 	 * @param string $hook      The hook of the action.
@@ -54,7 +56,9 @@ public static function has_scheduled_action( string $hook, array $args = [], str
 	 * @return int The action ID.
 	 */
 	public static function schedule_single_action( int $timestamp, string $hook, array $args = [], string $group = '', bool $unique = false, int $priority = 10 ): int {
-		return as_schedule_single_action( $timestamp, $hook, $args, $group, $unique, $priority );
+		$action_id = as_schedule_single_action( $timestamp, $hook, $args, $group, $unique, $priority );
+
+		return is_int( $action_id ) ? $action_id : 0;
 	}
 
 	/**
@@ -112,6 +116,7 @@ public static function get_actions_by_ids( array $action_ids ): array {
 	 * Gets pending actions by their IDs.
 	 *
 	 * @since 0.0.1
+	 * @since 0.0.7 Updated to filter out null actions.
 	 *
 	 * @param array $action_ids The action IDs.
 	 *
@@ -120,6 +125,6 @@ public static function get_actions_by_ids( array $action_ids ): array {
 	public static function get_pending_actions_by_ids( array $action_ids ): array {
 		$actions = self::get_actions_by_ids( $action_ids );
 
-		return array_filter( $actions, fn( ActionScheduler_Action $action ) => ! $action instanceof ActionScheduler_FinishedAction );
+		return array_filter( $actions, static fn( ActionScheduler_Action $action ) => ! $action instanceof ActionScheduler_FinishedAction && ! $action instanceof ActionScheduler_NullAction );
 	}
 }

src/Provider.php

@@ -59,6 +59,7 @@ class Provider extends Provider_Abstract {
 	 * Registers Shepherd's specific providers and starts core functionality
 	 *
 	 * @since 0.0.1
+	 * @since 0.0.7 Updated to register the regulator after the tables are registered successfully.
 	 *
 	 * @return void The method does not return any value.
 	 */
@@ -78,19 +79,38 @@ public function register(): void {
 		$this->container->singleton( Logger::class, Config::get_logger() );
 		$this->container->singleton( Tables_Provider::class );
 		$this->container->singleton( Regulator::class );
+
+		$prefix = Config::get_hook_prefix();
+
+		add_action( "shepherd_{$prefix}_tables_registered", [ $this, 'register_regulator' ] );
+
+		if ( ! has_action( "shepherd_{$prefix}_tables_error" ) ) {
+			_doing_it_wrong( __METHOD__, esc_html__( 'Your software should be handling the case where Shepherd tables are not registered successfully and notify your end users about it.', 'stellarwp-shepherd' ), '0.0.7' );
+		}
+
 		$this->container->get( Tables_Provider::class )->register();
-		$this->container->get( Regulator::class )->register();
 
 		add_action( 'action_scheduler_deleted_action', [ $this, 'delete_tasks_on_action_deletion' ] );
 
 		self::$has_registered = true;
 	}
 
+	/**
+	 * Registers the regulator.
+	 *
+	 * @since 0.0.7
+	 *
+	 * @return void
+	 */
+	public function register_regulator(): void {
+		$this->container->get( Regulator::class )->register();
+	}
+
 	/**
 	 * Requires Action Scheduler.
 	 *
 	 * @since 0.0.1
-	 * @since 0.0.2
+	 * @since 0.0.2 Look into multiple places for the action scheduler main file.
 	 *
 	 * @return void
 	 *