Add QM collector and outputter for SQLite query data

Register a custom QM collector that extracts SQLite queries from
$wpdb->queries, re-indexed to match QM's rendered row order, and a
client-side HTML outputter that emits the inline JS module used by
the QM 4.0 shadow DOM integration. QM auto-serializes the collector
data into window.QueryMonitorData.data.sqlite.

Author: JanJakes

packages/plugin-sqlite-database-integration/integrations/query-monitor/collector.php

@@ -0,0 +1,91 @@
+<?php // phpcs:disable WordPress.Files.FileName.InvalidClassFileName, Generic.Files.OneObjectStructurePerFile.MultipleFound
+
+if ( ! class_exists( 'QM_Collector' ) ) {
+	return;
+}
+
+/**
+ * Collector for SQLite query data.
+ *
+ * Extracts SQLite queries from $wpdb->queries and stores them
+ * indexed by SQL text for the QM 4.0+ JS integration.
+ */
+class SQLite_QM_Collector extends QM_Collector {
+	/** @var string */
+	public $id = 'sqlite';
+
+	public function process(): void {
+		global $wpdb;
+
+		if ( empty( $wpdb->queries ) ) {
+			return;
+		}
+
+		// Index by SQL rather than row position — robust to filtering, sorting, etc.
+		$mapped = array();
+		foreach ( $wpdb->queries as $query ) {
+			// Query Monitor skips queries with 'wp_admin_bar' in the stack.
+			if ( false !== strpos( $query[2] ?? '', 'wp_admin_bar' ) ) {
+				continue;
+			}
+			if ( ! empty( $query['sqlite_queries'] ) ) {
+				$sql            = trim( preg_replace( '/\s+/', ' ', $query[0] ) );
+				$mapped[ $sql ] = array_column( $query['sqlite_queries'], 'sql' );
+			}
+		}
+		$this->data->queries = $mapped;
+	}
+}
+
+/**
+ * HTML outputter for SQLite query data.
+ *
+ * With $client_side_rendered = true, QM auto-serializes the collector data
+ * into "window.QueryMonitorData.data.sqlite". This outputter's only job is to
+ * emit the inline JS module that reads that data and injects SQLite query
+ * details into QM 4.0's shadow DOM DB queries panel.
+ */
+class SQLite_QM_Output_Html extends QM_Output_Html {
+	/** @var bool */
+	public static $client_side_rendered = true;
+
+	public function name(): string {
+		return 'SQLite';
+	}
+
+	public function output(): void {
+		if ( empty( $this->get_collector()->get_data()->queries ) ) {
+			return;
+		}
+
+		$js_path = __DIR__ . '/query-monitor-sqlite.js';
+		if ( is_readable( $js_path ) ) {
+			echo '<script type="module">';
+			include $js_path;
+			echo '</script>';
+		}
+	}
+}
+
+/**
+ * Register the SQLite collector.
+ */
+function register_sqlite_qm_collector( array $collectors ): array {
+	$collectors['sqlite'] = new SQLite_QM_Collector();
+	return $collectors;
+}
+
+add_filter( 'qm/collectors', 'register_sqlite_qm_collector', 20 );
+
+/**
+ * Register the SQLite HTML outputter.
+ */
+function register_sqlite_qm_output_html( array $output, QM_Collectors $collectors ): array {
+	$collector = QM_Collectors::get( 'sqlite' );
+	if ( $collector ) {
+		$output['sqlite'] = new SQLite_QM_Output_Html( $collector );
+	}
+	return $output;
+}
+
+add_filter( 'qm/outputter/html', 'register_sqlite_qm_output_html', 30, 2 );