1<?php
2// This file is part of Moodle - http://moodle.org/
3//
4// Moodle is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8//
9// Moodle is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12// GNU General Public License for more details.
13//
14// You should have received a copy of the GNU General Public License
15// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
16
17/**
18 * Contains block_rss_client
19 * @package    block_rss_client
20 * @copyright  Daryl Hawes
21 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL
22 */
23
24/**
25 * A block which displays Remote feeds
26 *
27 * @package   block_rss_client
28 * @copyright  Daryl Hawes
29 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL
30 */
31
32 class block_rss_client extends block_base {
33    /** @var bool track whether any of the output feeds have recorded failures */
34    private $hasfailedfeeds = false;
35
36    function init() {
37        $this->title = get_string('pluginname', 'block_rss_client');
38    }
39
40    function applicable_formats() {
41        return array('all' => true, 'tag' => false);   // Needs work to make it work on tags MDL-11960
42    }
43
44    function specialization() {
45        // After the block has been loaded we customize the block's title display
46        if (!empty($this->config) && !empty($this->config->title)) {
47            // There is a customized block title, display it
48            $this->title = $this->config->title;
49        } else {
50            // No customized block title, use localized remote news feed string
51            $this->title = get_string('remotenewsfeed', 'block_rss_client');
52        }
53    }
54
55    /**
56     * Gets the footer, which is the channel link of the last feed in our list of feeds
57     *
58     * @param array $feedrecords The feed records from the database.
59     * @return block_rss_client\output\footer|null The renderable footer or null if none should be displayed.
60     */
61    protected function get_footer($feedrecords) {
62        $footer = null;
63
64        if ($this->config->block_rss_client_show_channel_link) {
65            global $CFG;
66            require_once($CFG->libdir.'/simplepie/moodle_simplepie.php');
67
68            $feedrecord     = array_pop($feedrecords);
69            $feed           = new moodle_simplepie($feedrecord->url);
70            $channellink    = new moodle_url($feed->get_link());
71
72            if (!empty($channellink)) {
73                $footer = new block_rss_client\output\footer($channellink);
74            }
75        }
76
77        if ($this->hasfailedfeeds) {
78            if (has_any_capability(['block/rss_client:manageownfeeds', 'block/rss_client:manageanyfeeds'], $this->context)) {
79                if ($footer === null) {
80                    $footer = new block_rss_client\output\footer();
81                }
82                $manageurl = new moodle_url('/blocks/rss_client/managefeeds.php',
83                        ['courseid' => $this->page->course->id]);
84                $footer->set_failed($manageurl);
85            }
86        }
87
88        return $footer;
89    }
90
91    function get_content() {
92        global $CFG, $DB;
93
94        if ($this->content !== NULL) {
95            return $this->content;
96        }
97
98        // initalise block content object
99        $this->content = new stdClass;
100        $this->content->text   = '';
101        $this->content->footer = '';
102
103        if (empty($this->instance)) {
104            return $this->content;
105        }
106
107        if (!isset($this->config)) {
108            // The block has yet to be configured - just display configure message in
109            // the block if user has permission to configure it
110
111            if (has_capability('block/rss_client:manageanyfeeds', $this->context)) {
112                $this->content->text = get_string('feedsconfigurenewinstance2', 'block_rss_client');
113            }
114
115            return $this->content;
116        }
117
118        // How many feed items should we display?
119        $maxentries = 5;
120        if ( !empty($this->config->shownumentries) ) {
121            $maxentries = intval($this->config->shownumentries);
122        }elseif( isset($CFG->block_rss_client_num_entries) ) {
123            $maxentries = intval($CFG->block_rss_client_num_entries);
124        }
125
126        /* ---------------------------------
127         * Begin Normal Display of Block Content
128         * --------------------------------- */
129
130        $renderer = $this->page->get_renderer('block_rss_client');
131        $block = new \block_rss_client\output\block();
132
133        if (!empty($this->config->rssid)) {
134            list($rssidssql, $params) = $DB->get_in_or_equal($this->config->rssid);
135            $rssfeeds = $DB->get_records_select('block_rss_client', "id $rssidssql", $params);
136
137            if (!empty($rssfeeds)) {
138                $showtitle = false;
139                if (count($rssfeeds) > 1) {
140                    // When many feeds show the title for each feed.
141                    $showtitle = true;
142                }
143
144                foreach ($rssfeeds as $feed) {
145                    if ($renderablefeed = $this->get_feed($feed, $maxentries, $showtitle)) {
146                        $block->add_feed($renderablefeed);
147                    }
148                }
149
150                $footer = $this->get_footer($rssfeeds);
151            }
152        }
153
154        $this->content->text = $renderer->render_block($block);
155        if (isset($footer)) {
156            $this->content->footer = $renderer->render_footer($footer);
157        }
158
159        return $this->content;
160    }
161
162
163    function instance_allow_multiple() {
164        return true;
165    }
166
167    function has_config() {
168        return true;
169    }
170
171    function instance_allow_config() {
172        return true;
173    }
174
175    /**
176     * Returns the html of a feed to be displaed in the block
177     *
178     * @param mixed feedrecord The feed record from the database
179     * @param int maxentries The maximum number of entries to be displayed
180     * @param boolean showtitle Should the feed title be displayed in html
181     * @return block_rss_client\output\feed|null The renderable feed or null of there is an error
182     */
183    public function get_feed($feedrecord, $maxentries, $showtitle) {
184        global $CFG;
185        require_once($CFG->libdir.'/simplepie/moodle_simplepie.php');
186
187        if ($feedrecord->skipuntil) {
188            // Last attempt to gather this feed via cron failed - do not try to fetch it now.
189            $this->hasfailedfeeds = true;
190            return null;
191        }
192
193        $simplepiefeed = new moodle_simplepie($feedrecord->url);
194
195        if(isset($CFG->block_rss_client_timeout)){
196            $simplepiefeed->set_cache_duration($CFG->block_rss_client_timeout * 60);
197        }
198
199        if ($simplepiefeed->error()) {
200            debugging($feedrecord->url .' Failed with code: '.$simplepiefeed->error());
201            return null;
202        }
203
204        if(empty($feedrecord->preferredtitle)){
205            // Simplepie does escape HTML entities.
206            $feedtitle = $this->format_title($simplepiefeed->get_title());
207        }else{
208            // Moodle custom title does not does escape HTML entities.
209            $feedtitle = $this->format_title(s($feedrecord->preferredtitle));
210        }
211
212        if (empty($this->config->title)){
213            //NOTE: this means the 'last feed' displayed wins the block title - but
214            //this is exiting behaviour..
215            $this->title = strip_tags($feedtitle);
216        }
217
218        $feed = new \block_rss_client\output\feed($feedtitle, $showtitle, $this->config->block_rss_client_show_channel_image);
219
220        if ($simplepieitems = $simplepiefeed->get_items(0, $maxentries)) {
221            foreach ($simplepieitems as $simplepieitem) {
222                try {
223                    $item = new \block_rss_client\output\item(
224                        $simplepieitem->get_id(),
225                        new moodle_url($simplepieitem->get_link()),
226                        $simplepieitem->get_title(),
227                        $simplepieitem->get_description(),
228                        new moodle_url($simplepieitem->get_permalink()),
229                        $simplepieitem->get_date('U'),
230                        $this->config->display_description
231                    );
232
233                    $feed->add_item($item);
234                } catch (moodle_exception $e) {
235                    // If there is an error with the RSS item, we don't
236                    // want to crash the page. Specifically, moodle_url can
237                    // throw an exception of the param is an extremely
238                    // malformed url.
239                    debugging($e->getMessage());
240                }
241            }
242        }
243
244        // Feed image.
245        if ($imageurl = $simplepiefeed->get_image_url()) {
246            try {
247                $image = new \block_rss_client\output\channel_image(
248                    new moodle_url($imageurl),
249                    $simplepiefeed->get_image_title(),
250                    new moodle_url($simplepiefeed->get_image_link())
251                );
252
253                $feed->set_image($image);
254            } catch (moodle_exception $e) {
255                // If there is an error with the RSS image, we don'twant to
256                // crash the page. Specifically, moodle_url can throw an
257                // exception if the param is an extremely malformed url.
258                debugging($e->getMessage());
259            }
260        }
261
262        return $feed;
263    }
264
265    /**
266     * Strips a large title to size and adds ... if title too long
267     * This function does not escape HTML entities, so they have to be escaped
268     * before being passed here.
269     *
270     * @param string title to shorten
271     * @param int max character length of title
272     * @return string title shortened if necessary
273     */
274    function format_title($title,$max=64) {
275
276        if (core_text::strlen($title) <= $max) {
277            return $title;
278        } else {
279            return core_text::substr($title, 0, $max - 3) . '...';
280        }
281    }
282
283    /**
284     * Return the plugin config settings for external functions.
285     *
286     * @return stdClass the configs for both the block instance and plugin
287     * @since Moodle 3.8
288     */
289    public function get_config_for_external() {
290        global $CFG;
291
292        // Return all settings for all users since it is safe (no private keys, etc..).
293        $instanceconfigs = !empty($this->config) ? $this->config : new stdClass();
294        $pluginconfigs = (object) [
295            'num_entries' => $CFG->block_rss_client_num_entries,
296            'timeout' => $CFG->block_rss_client_timeout
297        ];
298
299        return (object) [
300            'instance' => $instanceconfigs,
301            'plugin' => $pluginconfigs,
302        ];
303    }
304}
305