Dynamic category change

qa-include>lang>qa-lang-misc.php

<?php
/*
	Question2Answer by Gideon Greenspan and contributors
	http://www.question2answer.org/

	Description: Miscellaneous language phrases


	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
*/

return array(
	'block_ip_button' => 'Block IP address',
	'browse_categories' => 'Browse categories',
	'browse_category_x' => 'Browse category ^',
	'captcha_approve_fix' => 'This verification will stop appearing once your account is approved.',
	'captcha_confirm_fix' => 'To avoid this verification in future, please ^5confirm your email address^6.',
	'captcha_error' => 'Please complete the anti-spam verification',
	'captcha_label' => 'Anti-spam verification:',
	'captcha_login_fix' => 'To avoid this verification in future, please ^1log in^2 or ^3register^4.',
	'feed_a_edited_prefix' => 'Answer edited: ',
	'feed_a_prefix' => 'Answered: ',
	'feed_a_reshown_prefix' => 'Answer reshown: ',
	'feed_a_selected_prefix' => 'Answer selected: ',
	'feed_c_edited_prefix' => 'Comment edited: ',
	'feed_c_moved_prefix' => 'Comment moved: ',
	'feed_c_prefix' => 'Commented: ',
	'feed_c_reshown_prefix' => 'Comment reshown: ',
	'feed_closed_prefix' => 'Closed: ',
	'feed_edited_prefix' => 'Edited: ',
	'feed_hidden_prefix' => 'Hidden: ',
	'feed_not_found' => 'Feed not found',
	'feed_recategorized_prefix' => 'Recategorized: ',
	'feed_reopened_prefix' => 'Reopened: ',
	'feed_reshown_prefix' => 'Reshown: ',
	'feed_retagged_prefix' => 'Retagged: ',
	'feedback_email' => 'Your email: (optional)',
	'feedback_empty' => 'Please use this field to send some comments or suggestions',
	'feedback_message' => 'Your comments or suggestions for ^:',
	'feedback_name' => 'Your name: (optional)',
	'feedback_sent' => 'Your message below was sent - thank you.',
	'feedback_title' => 'Send feedback',
	'form_security_again' => 'Please click again to confirm',
	'form_security_reload' => 'Please reload the page then try again',
	'hide_all_ip_button' => 'Hide all posts from this IP',
	'host_name' => 'Host name:',
	'inbox' => 'Inbox',
	'matches_blocked_ips' => 'Matches blocked IP addresses:',
	'message_empty' => 'Please enter your message to send to this user',
	'message_explanation' => 'This will be sent as a notification from ^. Your email address will not be revealed unless you include it in the message.',
	'message_for_x' => 'Your message for ^:',
	'message_limit' => 'You cannot send more private messages this hour',
	'message_must_login' => 'Please ^1log in^2 or ^3register^4 to send private messages.',
	'message_recent_history' => 'Recent correspondence with ^',
	'message_sent' => 'Your private message below was sent',
	'more_favorite_qs' => 'More favorite questions...',
	'more_favorite_tags' => 'More favorite tags...',
	'more_favorite_users' => 'More favorite users...',
	'my_favorites_title' => 'My favorites',
	'nav_all_my_updates' => 'All my updates',
	'nav_my_content' => 'My content',
	'nav_my_details' => 'My account',
	'nav_my_favorites' => 'My favorites',
	'nav_user_activity' => 'Recent activity',
	'nav_user_as' => 'All answers',
	'nav_user_pms' => 'Private messages',
	'nav_user_qs' => 'All questions',
	'nav_user_wall' => 'Wall',
	'next_step' => 'Next step',
	'no_activity_from_x' => 'No activity from ^',
	'no_favorite_categories' => 'No favorite categories',
	'no_favorite_qs' => 'No favorite questions',
	'no_favorite_tags' => 'No favorite tags',
	'no_favorite_users' => 'No favorite users',
	'no_recent_updates' => 'No recent updates',
	'no_updates_content' => 'No recent updates for my content',
	'no_updates_favorites' => 'No updates for my favorites',
	'outbox' => 'Sent items',
	'pm_inbox_title' => 'Private messages received',
	'pm_outbox_title' => 'Private messages sent',
	'private_message_title' => 'Send a private message',
	'recent_activity_from_x' => 'Recent activity from ^',
	'recent_updates_content' => 'Recent updates for my content',
	'recent_updates_favorites' => 'Recent updates for my favorites',
	'recent_updates_title' => 'Recent updates for me',
	'site_in_maintenance' => 'This site is currently down for maintenance - please come back soon.',
	'suggest_favorites_add' => 'To add a question or other item to your favorites, click the ^ at the top of its page.',
	'suggest_update_favorites' => 'For more updates, add items to ^1your favorites^2.',
	'unblock_ip_button' => 'Unblock IP address',
	'your_a_commented' => 'your answer commented',
	'your_a_edited' => 'your answer edited',
	'your_a_hidden' => 'your answer hidden',
	'your_a_questioned' => 'asked on your answer',
	'your_a_reshown' => 'your answer reshown',
	'your_a_selected' => 'your answer selected',
	'your_c_edited' => 'your comment edited',
	'your_c_followed' => 'your comment followed',
	'your_c_hidden' => 'your comment hidden',
	'your_c_moved' => 'your comment moved',
	'your_c_reshown' => 'your comment reshown',
	'your_q_answered' => 'your question answered',
	'your_q_closed' => 'your question closed',
	'your_q_commented' => 'your question commented',
	'your_q_edited' => 'your question edited',
	'your_q_hidden' => 'your question hidden',
	'your_q_recategorized' => 'your question recategorized',
	'your_q_reopened' => 'your question reopened',
	'your_q_reshown' => 'your question reshown',
	'your_q_retagged' => 'your question retagged',
);

qa-include>pages>categories.php

<?php
/*
	Question2Answer by Gideon Greenspan and contributors
	http://www.question2answer.org/

	Description: Controller for page listing categories


	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
*/

if (!defined('QA_VERSION')) { // don't allow this page to be requested directly from browser
	header('Location: ../../');
	exit;
}

require_once QA_INCLUDE_DIR . 'db/selects.php';
require_once QA_INCLUDE_DIR . 'app/format.php';


$categoryslugs = qa_request_parts(1);
$hasSlugs = !empty($categoryslugs);


// Get information about appropriate categories and redirect to questions page if category has no sub-categories

$userid = qa_get_logged_in_userid();
list($categories, $categoryid, $favoritecats) = qa_db_select_with_pending(
	qa_db_category_nav_selectspec($categoryslugs, false, false, true),
	$hasSlugs ? qa_db_slugs_to_category_id_selectspec($categoryslugs) : null,
	isset($userid) ? qa_db_user_favorite_categories_selectspec($userid) : null
);

if ($hasSlugs && !isset($categoryid)) {
	return include QA_INCLUDE_DIR . 'qa-page-not-found.php';
}


// Function for recursive display of categories

function qa_category_nav_to_browse(&$navigation, $categories, $categoryid, $favoritemap)
{
	foreach ($navigation as $key => $navlink) {
		$category = $categories[$navlink['categoryid']];

		if (!$category['childcount']) {
			unset($navigation[$key]['url']);
		} elseif ($navlink['selected']) {
			$navigation[$key]['state'] = 'open';
			$navigation[$key]['url'] = qa_path_html('categories/' . qa_category_path_request($categories, $category['parentid']));
		} else
			$navigation[$key]['state'] = 'closed';

		if (@$favoritemap[$navlink['categoryid']]) {
			$navigation[$key]['favorited'] = true;
		}

		$navigation[$key]['note'] =
			' - <a href="'.qa_path_html('questions/'.implode('/', array_reverse(explode('/', $category['backpath'])))).'">'.( ($category['qcount']==1)
				? qa_lang_html_sub('main/1_question', '1', '1')
				: qa_lang_html_sub('main/x_questions', number_format($category['qcount']))
			).'</a>';

		if (strlen($category['content']))
			$navigation[$key]['note'] .= qa_html(' - ' . $category['content']);

		if (isset($navlink['subnav']))
			qa_category_nav_to_browse($navigation[$key]['subnav'], $categories, $categoryid, $favoritemap);
	}
}


// Prepare content for theme

$qa_content = qa_content_prepare(false, array_keys(qa_category_path($categories, $categoryid)));
$qa_content['title'] = $hasSlugs ? qa_lang_html_sub('misc/browse_category_x', $categories[$categoryid]['title']) : qa_lang_html('misc/browse_categories');

if (count($categories)) {
	$navigation = qa_category_navigation($categories, $categoryid, 'categories/', false);

	unset($navigation['all']);

	$favoritemap = array();
	if (isset($favoritecats)) {
		foreach ($favoritecats as $category) {
			$favoritemap[$category['categoryid']] = true;
		}
	}

	qa_category_nav_to_browse($navigation, $categories, $categoryid, $favoritemap);

	$qa_content['nav_list'] = array(
		'nav' => $navigation,
		'type' => 'browse-cat',
	);

} else {
	$qa_content['title'] = qa_lang_html('main/no_categories_found');
	$qa_content['suggest_next'] = qa_html_suggest_qs_tags(qa_using_tags());
}


return $qa_content;