pakfire.cgi: Implement JavaScript log message display

Currently the page becomes unresponsive while Pakfire is busy.
This patch implements a AJAX/JSON driven log output, to provide
continuous information to the user while Pakfire is running.

The output is updated 1x per second, if the load should be too high,
the interval can be change by writing to "pakfire.refreshInterval".

Signed-off-by: Leo-Andres Hofmann <hofmann@leo-andres.de>

html/html/include/pakfire.js

@@ -0,0 +1,241 @@
+/*#############################################################################
+#                                                                             #
+# IPFire.org - A linux based firewall                                         #
+# Copyright (C) 2007-2021  IPFire Team  <info@ipfire.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 3 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.                                #
+#                                                                             #
+# You should have received a copy of the GNU General Public License           #
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
+#                                                                             #
+#############################################################################*/
+
+"use strict";
+
+// Pakfire Javascript functions (requires jQuery)
+class PakfireJS {
+	constructor() {
+		//--- Public properties ---
+		// Translation strings
+		this.i18n = new PakfireI18N();
+
+		//--- Private properties ---
+		// Status flags (access outside constructor only with setter/getter)
+		this._states = Object.create(null);
+		this._states.running = false;
+		this._states.reboot = false;
+
+		// Status refresh helper
+		this._autoRefresh = {
+			delay: 1000, //Delay between requests (default: 1s)
+			jsonAction: 'getstatus', //CGI POST action parameter
+			timeout: 5000, //XHR timeout (5s)
+
+			delayTimer: null, //setTimeout reference
+			jqXHR: undefined, //jQuery.ajax promise reference
+			get runningDelay() { //Waiting for end of delay
+				return (this.delayTimer !== null);
+			},
+			get runningXHR() { //Waiting for CGI response
+				return (this.jqXHR && (this.jqXHR.state() === 'pending'));
+			},
+			get isRunning() {
+				return (this.runningDelay || this.runningXHR);
+			}
+		};
+	}
+
+	//### Public properties ###
+
+	// Pakfire is running (true/false)
+	set running(state) {
+		if(this._states.running !== state) {
+			this._states.running = state;
+			this._states_onChange('running');
+		}
+	}
+	get running() {
+		return this._states.running;
+	}
+
+	// Reboot needed (true/false)
+	set reboot(state) {
+		if(this._states.reboot !== state) {
+			this._states.reboot = state;
+			this._states_onChange('reboot');
+		}
+	}
+	get reboot() {
+		return this._states.reboot;
+	}
+
+	// Status refresh interval in ms
+	set refreshInterval(delay) {
+		if(delay < 500) {
+			delay = 500; //enforce reasonable minimum
+		}
+		this._autoRefresh.delay = delay;
+	}
+	get refreshInterval() {
+		return this._autoRefresh.delay;
+	}
+
+	// Document loaded (call once from jQuery.ready)
+	documentReady() {
+		// Status refresh late start
+		if(this.running && (! this._autoRefresh.isRunning)) {
+			this._autoRefresh_runNow();
+		}
+	}
+
+	//### Private properties ###
+
+	// Pakfire status change handler
+	// property: Affected status (running, reboot, ...)
+	_states_onChange(property) {
+		// Always update UI
+		if(this.running) {
+			$('#pflog-status').text(this.i18n.get('working'));
+			$('#pflog-action').empty();
+		} else {
+			$('#pflog-status').text(this.i18n.get('finished'));
+			if(this.reboot) { //Enable return or reboot links in UI
+				$('#pflog-action').html(this.i18n.get('link_reboot'));
+			} else {
+				$('#pflog-action').html(this.i18n.get('link_return'));
+			}
+		}
+
+		// Start/stop status refresh if Pakfire started/stopped
+		if(property === 'running') {
+			if(this.running) {
+				this._autoRefresh_runNow();
+			} else {
+				this._autoRefresh_clearSchedule();
+			}
+		}
+	}
+
+	//--- Status refresh scheduling functions ---
+
+	// Immediately perform AJAX status refresh request
+	_autoRefresh_runNow() {
+		if(this._autoRefresh.runningXHR) {
+			return; // Don't send multiple requests
+		}
+		this._autoRefresh_clearSchedule(); // Stop scheduled refresh, will send immediately
+
+		// Send AJAX request, attach listeners
+		this._autoRefresh.jqXHR = this._JSON_get(this._autoRefresh.jsonAction, this._autoRefresh.timeout);
+		this._autoRefresh.jqXHR.done(function() { // Request succeeded
+			if(this.running) { // Keep refreshing while Pakfire is running
+				this._autoRefresh_scheduleRun();
+			}
+		});
+		this._autoRefresh.jqXHR.fail(function() { // Request failed
+			this._autoRefresh_scheduleRun(); // Try refreshing until valid status is received
+		});
+	}
+
+	// Schedule next refresh
+	_autoRefresh_scheduleRun() {
+		if(this._autoRefresh.runningDelay || this._autoRefresh.runningXHR) {
+			return; // Refresh already scheduled or in progress
+		}
+		this._autoRefresh.delayTimer = window.setTimeout(function() {
+			this._autoRefresh.delayTimer = null;
+			this._autoRefresh_runNow();
+		}.bind(this), this._autoRefresh.delay);
+	}
+
+	// Stop scheduled refresh (can still be refreshed up to 1x if XHR is already sent)
+	_autoRefresh_clearSchedule() {
+		if(this._autoRefresh.runningDelay) {
+			window.clearTimeout(this._autoRefresh.delayTimer);
+			this._autoRefresh.delayTimer = null;
+		}
+	}
+
+	//--- JSON request & data handling ---
+
+	// Load JSON data from Pakfire CGI, using a POST request
+	// action: POST paramter "json-[action]"
+	// maxTime: XHR timeout, 0 = no timeout
+	_JSON_get(action, maxTime = 0) {
+		return $.ajax({
+			url: '/cgi-bin/pakfire.cgi',
+			method: 'POST',
+			timeout: maxTime,
+			context: this,
+			data: {'ACTION': `json-${action}`},
+			dataType: 'json' //automatically check and convert result
+		})
+			.done(function(response) {
+				this._JSON_process(action, response);
+			});
+	}
+
+	// Process successful response from Pakfire CGI
+	// action: POST paramter "json-[action]" used to send request
+	// data: JSON data object
+	_JSON_process(action, data) {
+		// Pakfire status refresh
+		if(action === this._autoRefresh.jsonAction) {
+			// Update status flags
+			this.running = (data['running'] != '0');
+			this.reboot = (data['reboot'] != '0');
+
+			// Update timer display
+			if(this.running && data['running_since']) {
+				$('#pflog-time').text(this.i18n.get('since') + data['running_since']);
+			} else {
+				$('#pflog-time').empty();
+			}
+
+			// Print log messages
+			let messages = "";
+			data['messages'].forEach(function(line) {
+				messages += `${line}\n`;
+			});
+			$('#pflog-messages').text(messages);
+		}
+	}
+}
+
+// Simple translation strings helper
+// Format: {key: "translation"}
+class PakfireI18N {
+	constructor() {
+		this._strings = Object.create(null); //Object without prototypes
+	}
+
+	// Get translation
+	get(key) {
+		if(Object.prototype.hasOwnProperty.call(this._strings, key)) {
+			return this._strings[key];
+		}
+		return `(undefined string '${key}')`;
+	}
+
+	// Load key/translation object
+	load(translations) {
+		if(translations instanceof Object) {
+			Object.assign(this._strings, translations);
+		}
+	}
+}
+
+//### Initialize Pakfire ###
+const pakfire = new PakfireJS();
+
+$(function() {
+	pakfire.documentReady();
+});