<?php /* Question2Answer (c) Gideon Greenspan http://www.question2answer.org/ File: qa-include/qa-feed.php Version: See define()s at top of qa-include/qa-base.php Description: Handles all requests to RSS feeds, first checking if they should be available 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; } @ini_set('display_errors', 0); // we don't want to show PHP errors to RSS readers qa_report_process_stage('init_feed'); require_once QA_INCLUDE_DIR.'qa-app-options.php'; // Functions used within this file function qa_feed_db_fail_handler($type, $errno=null, $error=null, $query=null) /* Database failure handler function for RSS feeds - outputs HTTP and text errors */ { header('HTTP/1.1 500 Internal Server Error'); echo qa_lang_html('main/general_error'); qa_exit('error'); } function qa_feed_not_found() /* Common function called when a non-existent feed is requested - outputs HTTP and text errors */ { header('HTTP/1.0 404 Not Found'); echo qa_lang_html('misc/feed_not_found'); qa_exit(); } function qa_feed_load_ifcategory($categoryslugs, $allkey, $catkey, &$title, $questionselectspec1=null, $questionselectspec2=null, $questionselectspec3=null, $questionselectspec4=null) /* Common function to load appropriate set of questions for requested feed, check category exists, and set up page title */ { $countslugs=@count($categoryslugs); list($questions1, $questions2, $questions3, $questions4, $categories, $categoryid)=qa_db_select_with_pending( $questionselectspec1, $questionselectspec2, $questionselectspec3, $questionselectspec4, $countslugs ? qa_db_category_nav_selectspec($categoryslugs, false) : null, $countslugs ? qa_db_slugs_to_category_id_selectspec($categoryslugs) : null ); if ($countslugs && !isset($categoryid)) qa_feed_not_found(); if (isset($allkey)) $title=(isset($categoryid) && isset($catkey)) ? qa_lang_sub($catkey, $categories[$categoryid]['title']) : qa_lang($allkey); return array_merge( is_array($questions1) ? $questions1 : array(), is_array($questions2) ? $questions2 : array(), is_array($questions3) ? $questions3 : array(), is_array($questions4) ? $questions4 : array() ); } // Connect to database and get the type of feed and category requested (in some cases these are overridden later) qa_db_connect('qa_feed_db_fail_handler'); qa_preload_options(); $requestlower=strtolower(qa_request()); $foursuffix=substr($requestlower, -4); if ( ($foursuffix=='.rss') || ($foursuffix=='.xml') ) $requestlower=substr($requestlower, 0, -4); $requestlowerparts=explode('/', $requestlower); $feedtype=@$requestlowerparts[1]; $feedparams=array_slice($requestlowerparts, 2); // Choose which option needs to be checked to determine if this feed can be requested, and stop if no matches $feedoption=null; $categoryslugs=$feedparams; switch ($feedtype) { case 'questions': $feedoption='feed_for_questions'; break; case 'hot': $feedoption='feed_for_hot'; if (!QA_ALLOW_UNINDEXED_QUERIES) $categoryslugs=null; break; case 'unanswered': $feedoption='feed_for_unanswered'; if (!QA_ALLOW_UNINDEXED_QUERIES) $categoryslugs=null; break; case 'answers': case 'comments': case 'activity': $feedoption='feed_for_activity'; break; case 'qa': $feedoption='feed_for_qa'; break; case 'tag': if (strlen(@$feedparams[0])) { $feedoption='feed_for_tag_qs'; $categoryslugs=null; } break; case 'search': if (strlen(@$feedparams[0])) { $feedoption='feed_for_search'; $categoryslugs=null; } break; } $countslugs=@count($categoryslugs); if (!isset($feedoption)) qa_feed_not_found(); // Check that all the appropriate options are in place to allow this feed to be retrieved if (!( (qa_opt($feedoption)) && ($countslugs ? (qa_using_categories() && qa_opt('feed_per_category')) : true) )) qa_feed_not_found(); // Retrieve the appropriate questions and other information for this feed require_once QA_INCLUDE_DIR.'qa-db-selects.php'; $sitetitle=qa_opt('site_title'); $siteurl=qa_opt('site_url'); $full=qa_opt('feed_full_text'); $count=qa_opt('feed_number_items'); $showurllinks=qa_opt('show_url_links'); $linkrequest=$feedtype.($countslugs ? ('/'.implode('/', $categoryslugs)) : ''); $linkparams=null; switch ($feedtype) { case 'questions': $questions=qa_feed_load_ifcategory($categoryslugs, 'main/recent_qs_title', 'main/recent_qs_in_x', $title, qa_db_qs_selectspec(null, 'created', 0, $categoryslugs, null, false, $full, $count) ); break; case 'hot': $questions=qa_feed_load_ifcategory($categoryslugs, 'main/hot_qs_title', 'main/hot_qs_in_x', $title, qa_db_qs_selectspec(null, 'hotness', 0, $categoryslugs, null, false, $full, $count) ); break; case 'unanswered': $questions=qa_feed_load_ifcategory($categoryslugs, 'main/unanswered_qs_title', 'main/unanswered_qs_in_x', $title, qa_db_unanswered_qs_selectspec(null, null, 0, $categoryslugs, false, $full, $count) ); break; case 'answers': $questions=qa_feed_load_ifcategory($categoryslugs, 'main/recent_as_title', 'main/recent_as_in_x', $title, qa_db_recent_a_qs_selectspec(null, 0, $categoryslugs, null, false, $full, $count) ); break; case 'comments': $questions=qa_feed_load_ifcategory($categoryslugs, 'main/recent_cs_title', 'main/recent_cs_in_x', $title, qa_db_recent_c_qs_selectspec(null, 0, $categoryslugs, null, false, $full, $count) ); break; case 'qa': $questions=qa_feed_load_ifcategory($categoryslugs, 'main/recent_qs_as_title', 'main/recent_qs_as_in_x', $title, qa_db_qs_selectspec(null, 'created', 0, $categoryslugs, null, false, $full, $count), qa_db_recent_a_qs_selectspec(null, 0, $categoryslugs, null, false, $full, $count) ); break; case 'activity': $questions=qa_feed_load_ifcategory($categoryslugs, 'main/recent_activity_title', 'main/recent_activity_in_x', $title, qa_db_qs_selectspec(null, 'created', 0, $categoryslugs, null, false, $full, $count), qa_db_recent_a_qs_selectspec(null, 0, $categoryslugs, null, false, $full, $count), qa_db_recent_c_qs_selectspec(null, 0, $categoryslugs, null, false, $full, $count), qa_db_recent_edit_qs_selectspec(null, 0, $categoryslugs, null, true, $full, $count) ); break; case 'tag': $tag=$feedparams[0]; $questions=qa_feed_load_ifcategory(null, null, null, $title, qa_db_tag_recent_qs_selectspec(null, $tag, 0, $full, $count) ); $title=qa_lang_sub('main/questions_tagged_x', $tag); $linkrequest='tag/'.$tag; break; case 'search': require_once QA_INCLUDE_DIR.'qa-app-search.php'; $query=$feedparams[0]; $results=qa_get_search_results($query, 0, $count, null, true, $full); $title=qa_lang_sub('main/results_for_x', $query); $linkrequest='search'; $linkparams=array('q' => $query); $questions=array(); foreach ($results as $result) { $setarray=array( 'title' => $result['title'], 'url' => $result['url'], ); if (isset($result['question'])) $questions[]=array_merge($result['question'], $setarray); elseif (isset($result['url'])) $questions[]=$setarray; } break; } // Remove duplicate questions (perhaps referenced in an answer and a comment) and cut down to size require_once QA_INCLUDE_DIR.'qa-app-format.php'; require_once QA_INCLUDE_DIR.'qa-app-updates.php'; require_once QA_INCLUDE_DIR.'qa-util-string.php'; if ( ($feedtype!='search') && ($feedtype!='hot') ) // leave search results and hot questions sorted by relevance $questions=qa_any_sort_and_dedupe($questions); $questions=array_slice($questions, 0, $count); $blockwordspreg=qa_get_block_words_preg(); // Prepare the XML output $lines=array(); $lines[]='<?xml version="1.0" encoding="utf-8"?>'; $lines[]='<rss version="2.0">'; $lines[]='<channel>'; $lines[]='<title>'.qa_xml($sitetitle.' - '.$title).'</title>'; $lines[]='<link>'.qa_xml(qa_path($linkrequest, $linkparams, $siteurl)).'</link>'; $lines[]='<description>Powered by Question2Answer</description>'; foreach ($questions as $question) { // Determine whether this is a question, answer or comment, and act accordingly $options=array('blockwordspreg' => @$blockwordspreg, 'showurllinks' => $showurllinks); $time=null; $htmlcontent=null; if (isset($question['opostid'])) { $time=$question['otime']; if ($full) $htmlcontent=qa_viewer_html($question['ocontent'], $question['oformat'], $options); } elseif (isset($question['postid'])) { $time=$question['created']; if ($full) $htmlcontent=qa_viewer_html($question['content'], $question['format'], $options); } if ($feedtype=='search') { $titleprefix=''; $urlxml=qa_xml($question['url']); } else { switch (@$question['obasetype'].'-'.@$question['oupdatetype']) { case 'Q-': case '-': $langstring=null; break; case 'Q-'.QA_UPDATE_VISIBLE: $langstring=$question['hidden'] ? 'misc/feed_hidden_prefix' : 'misc/feed_reshown_prefix'; break; case 'Q-'.QA_UPDATE_CLOSED: $langstring=isset($question['closedbyid']) ? 'misc/feed_closed_prefix' : 'misc/feed_reopened_prefix'; break; case 'Q-'.QA_UPDATE_TAGS: $langstring='misc/feed_retagged_prefix'; break; case 'Q-'.QA_UPDATE_CATEGORY: $langstring='misc/feed_recategorized_prefix'; break; case 'A-': $langstring='misc/feed_a_prefix'; break; case 'A-'.QA_UPDATE_SELECTED: $langstring='misc/feed_a_selected_prefix'; break; case 'A-'.QA_UPDATE_VISIBLE: $langstring=$question['ohidden'] ? 'misc/feed_hidden_prefix' : 'misc/feed_a_reshown_prefix'; break; case 'A-'.QA_UPDATE_CONTENT: $langstring='misc/feed_a_edited_prefix'; break; case 'C-': $langstring='misc/feed_c_prefix'; break; case 'C-'.QA_UPDATE_TYPE: $langstring='misc/feed_c_moved_prefix'; break; case 'C-'.QA_UPDATE_VISIBLE: $langstring=$question['ohidden'] ? 'misc/feed_hidden_prefix' : 'misc/feed_c_reshown_prefix'; break; case 'C-'.QA_UPDATE_CONTENT: $langstring='misc/feed_c_edited_prefix'; break; case 'Q-'.QA_UPDATE_CONTENT: default: $langstring='misc/feed_edited_prefix'; break; } $titleprefix=isset($langstring) ? qa_lang($langstring) : ''; $urlxml=qa_xml(qa_q_path($question['postid'], $question['title'], true, @$question['obasetype'], @$question['opostid'])); } if (isset($blockwordspreg)) $question['title']=qa_block_words_replace($question['title'], $blockwordspreg); // Build the inner XML structure for each item $lines[]='<item>'; $lines[]='<title>'.qa_xml($titleprefix.$question['title']).'</title>'; $lines[]='<link>'.$urlxml.'</link>'; if (isset($htmlcontent)) $lines[]='<description>'.qa_xml($htmlcontent).'</description>'; if (isset($question['categoryname'])) $lines[]='<category>'.qa_xml($question['categoryname']).'</category>'; $lines[]='<guid isPermaLink="true">'.$urlxml.'</guid>'; if (isset($time)) $lines[]='<pubDate>'.qa_xml(gmdate('r', $time)).'</pubDate>'; $lines[]='</item>'; } $lines[]='</channel>'; $lines[]='</rss>'; // Disconnect here, once all output is ready to go qa_db_disconnect(); // Output the XML - and we're done! header('Content-type: text/xml; charset=utf-8'); echo implode("\n", $lines); /* Omit PHP closing tag to help avoid accidental output */