Update recalc logic to be resumable

qa-content/qa-admin.js

@@ -19,76 +19,128 @@
 	More about this license: http://www.question2answer.org/license.php
 */
 
-var qa_recalc_running = 0;
+const qa_recalcProcesses = new Map();
 
-window.onbeforeunload = function(event)
-{
-	if (qa_recalc_running > 0) {
-		event = event || window.event;
-		var message = qa_warning_recalc;
-		event.returnValue = message;
-		return message;
+window.onbeforeunload = event => {
+	for (const [processKey, process] of qa_recalcProcesses.entries()) {
+		if (process.clientRunning) {
+			event.preventDefault();
+			event.returnValue = true;
+		}
 	}
 };
 
-function qa_recalc_click(state, elem, value, noteid)
+/**
+ * @param {string} processKey
+ * @param {Object} options - Object used to configure the process
+ * @param {boolean} [options.forceRestart = false] - Whether the click has to trigger a restart of the process
+ * @param {boolean} [options.requiresServerTracking = true] - Whether the process is expected to be stopped and resumed
+ * @param {(process: object) => void} [options.callbackStart] - Callback run when the process is started
+ * @param {(process: object, hasFinished: boolean) => void} [options.callbackStop] - Callback run when the process is stopped
+ * @returns {boolean}
+ */
+function qa_recalc_click(processKey, options = {})
 {
-	if (elem.qa_recalc_running) {
-		elem.qa_recalc_stopped = true;
+	options = {
+		forceRestart: false,
+		requiresServerTracking: true,
+		...options,
+	};
+
+	let process = qa_recalcProcesses.get(processKey) ?? {processKey: processKey};
+
+	const startButton = document.getElementById(processKey);
+	const continueButton = document.getElementById(processKey + '_continue');
+	const statusLabel = document.getElementById(processKey + '_status');
 
+	if (process.clientRunning) {
+		process.stopRequest = true;
 	} else {
-		elem.qa_recalc_running = true;
-		elem.qa_recalc_stopped = false;
-		qa_recalc_running++;
+		process = {
+			...process,
+			"startButton": startButton,
+			"continueButton": continueButton,
+			"statusLabel": statusLabel,
+			"clientRunning": true,
+			"stopRequest": false,
+			"startListeners": options.callbackStart ? [options.callbackStart] : [],
+			"stopListeners": options.callbackStop ? [options.callbackStop] : [],
+			"options": options
+		};
 
-		document.getElementById(noteid).innerHTML = '';
-		elem.qa_original_value = elem.value;
-		if (value)
-			elem.value = value;
+		qa_recalcProcesses.set(processKey, process);
 
-		qa_recalc_update(elem, state, noteid);
+		qa_conceal(process.continueButton);
+
+		statusLabel.innerHTML = qa_langs.please_wait;
+		startButton.value = qa_langs.process_stop;
+
+		process.startListeners.forEach(listener => listener(process));
+
+		qa_recalc_update(process);
 	}
 
 	return false;
 }
 
-function qa_recalc_update(elem, state, noteid)
+function qa_recalc_update(process)
 {
-	if (state) {
-		var recalcCode = elem.form.elements.code_recalc ? elem.form.elements.code_recalc.value : elem.form.elements.code.value;
-		qa_ajax_post(
-			'recalc',
-			{state: state, code: recalcCode},
-			function(lines) {
-				if (lines[0] == '1') {
-					if (lines[2])
-						document.getElementById(noteid).innerHTML = lines[2];
-
-					if (elem.qa_recalc_stopped)
-						qa_recalc_cleanup(elem);
-					else
-						qa_recalc_update(elem, lines[1], noteid);
-
-				} else if (lines[0] == '0') {
-					document.getElementById(noteid).innerHTML = lines[1];
-					qa_recalc_cleanup(elem);
-
-				} else {
+	const recalcCode = process.startButton.form.elements.code.value;
+
+	qa_ajax_post(
+		'recalc',
+		{
+			process: process.processKey,
+			forceRestart: process.options.forceRestart,
+			code: recalcCode
+		},
+		function (lines) {
+			const result = lines[0] ?? null;
+			const message = lines[1] ?? null;
+			const hasFinished = (lines[2] ?? '0') === '1';
+
+			switch (result) {
+				case '1':
+					if (message !== null) {
+						process.statusLabel.innerHTML = message;
+					}
+
+					process.serverProcessPending = process.options.requiresServerTracking ? !hasFinished : false;
+					if (hasFinished || process.stopRequest) {
+						qa_recalc_cleanup(process, hasFinished);
+					} else {
+						process.options.forceRestart = false;
+						qa_recalc_update(process);
+					}
+					break;
+				case '0':
+					process.statusLabel.innerHTML = message;
+					process.serverProcessPending = true;
+					qa_recalc_cleanup(process, false, message);
+					break;
+				default:
+					process.serverProcessPending = true;
+					qa_recalc_cleanup(process);
 					qa_ajax_error();
-					qa_recalc_cleanup(elem);
-				}
 			}
-		);
-	} else {
-		qa_recalc_cleanup(elem);
-	}
+		}
+	);
 }
 
-function qa_recalc_cleanup(elem)
+function qa_recalc_cleanup(process, hasFinished = false, message = null)
 {
-	elem.value = elem.qa_original_value;
-	elem.qa_recalc_running = null;
-	qa_recalc_running--;
+	process.clientRunning = false;
+
+	process.stopListeners.forEach(listener => listener(process, hasFinished));
+
+	if (process.options.requiresServerTracking && process.serverProcessPending) {
+		process.startButton.value = qa_langs.process_restart;
+		process.statusLabel.innerHTML = message ?? qa_langs.process_unfinished;
+		qa_reveal(process.continueButton);
+	} else {
+		process.startButton.value = qa_langs.process_start;
+		qa_conceal(process.continueButton);
+	}
 }
 
 function qa_mailing_start(noteid, pauseid)

qa-include/Q2A/Admin/Recalc/AbstractProcessManager.php

@@ -0,0 +1,123 @@
+<?php
+
+/*
+	Question2Answer by Gideon Greenspan and contributors
+	http://www.question2answer.org/
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation; either version 2
+	of the License, or (at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	More about this license: http://www.question2answer.org/license.php
+*/
+
+abstract class Q2A_Admin_Recalc_AbstractProcessManager
+{
+	/** @var string */
+	protected $stateOption;
+
+	/** @var int */
+	protected $currentStepIndex = 0;
+
+	/** @var array */
+	protected $steps;
+
+	/**
+	 * @return array Return step and process state data
+	 */
+	public function execute($forceRestart = false)
+	{
+		$newStep = false;
+
+		try {
+			if ($forceRestart) {
+				throw new Exception('Force exception');
+			}
+
+			$step = $this->loadState();
+
+			if ($step->isFinished()) {
+				$this->currentStepIndex++;
+
+				if ($this->currentStepIndex >= count($this->steps)) {
+					$this->clearState();
+
+					return [
+						'process_finished' => true,
+						'message' => qa_lang('admin/process_complete'),
+					];
+				}
+
+				$newStep = true;
+				$step = $this->getCurrentStepInstance();
+			}
+		} catch (Exception $e) {
+			$step = $this->getCurrentStepInstance();
+			$newStep = true;
+		}
+
+		if ($newStep) {
+			$step->setup();
+		} else {
+			$step->execute();
+		}
+
+		$result = [
+			'step_state' => $step->asArray(),
+			'step_index' => $this->currentStepIndex,
+			'process_finished' => false,
+		];
+		$this->saveState($result);
+
+		$result['message'] = $step->getMessage();
+
+		return $result;
+	}
+
+	/**
+	 * @throws Exception
+	 */
+	private function loadState()
+	{
+		$state = qa_opt($this->stateOption);
+		$state = json_decode($state, true);
+
+		if (!isset($state['step_index'])) {
+			throw new Exception('Nothing to load');
+		}
+
+		$this->currentStepIndex = $state['step_index'];
+
+		$step = $this->getCurrentStepInstance();
+		$step->loadFromJson($state['step_state']);
+
+		return $step;
+	}
+
+	private function saveState($state)
+	{
+		qa_opt($this->stateOption, json_encode($state));
+	}
+
+	private function clearState()
+	{
+		qa_opt($this->stateOption, '');
+	}
+
+	/**
+	 * @return Q2A_Admin_Recalc_AbstractStep
+	 */
+	protected function getCurrentStepInstance()
+	{
+		// Make sure the step index to instantiate is valid
+		$this->currentStepIndex = min(max(0, $this->currentStepIndex), count($this->steps) - 1);
+
+		return new $this->steps[$this->currentStepIndex];
+	}
+}

qa-include/Q2A/Admin/Recalc/AbstractStep.php

@@ -0,0 +1,84 @@
+<?php
+
+/*
+	Question2Answer by Gideon Greenspan and contributors
+	http://www.question2answer.org/
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation; either version 2
+	of the License, or (at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	More about this license: http://www.question2answer.org/license.php
+*/
+
+abstract class Q2A_Admin_Recalc_AbstractStep
+{
+	/** @var int|null */
+	protected $processedItems = 0;
+
+	/** @var int|null */
+	protected $totalItems;
+
+	/** @var mixed */
+	protected $nextItemId = 0;
+
+	/** @var mixed */
+	protected $lastProcessedItemId = 0;
+
+	/** @var bool */
+	protected $isFinished = false;
+
+	/** @var string */
+	protected $messageLangId = '';
+
+	abstract public function setup();
+
+	abstract public function execute();
+
+	/**
+	 * @return array
+	 */
+	public function asArray()
+	{
+		return [
+			'is_finished' => $this->isFinished,
+			'processed_items' => $this->processedItems,
+			'total_items' => $this->totalItems,
+			'next_item_id' => $this->nextItemId,
+			'last_processed_item_id' => $this->lastProcessedItemId,
+		];
+	}
+
+	public function loadFromJson($state)
+	{
+		$this->isFinished = $state['is_finished'];
+		$this->processedItems = $state['processed_items'];
+		$this->totalItems = $state['total_items'];
+		$this->nextItemId = $state['next_item_id'];
+		$this->lastProcessedItemId = $state['last_processed_item_id'];
+	}
+
+	/**
+	 * @return bool
+	 */
+	public function isFinished()
+	{
+		return $this->isFinished;
+	}
+
+	public function getMessage()
+	{
+		require_once QA_INCLUDE_DIR . 'app/format.php';
+
+		return strtr(qa_lang($this->messageLangId), array(
+			'^1' => qa_format_number($this->processedItems),
+			'^2' => qa_format_number($this->totalItems),
+		));
+	}
+}