Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle 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.

//

// Moodle 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 Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * Classes for Blogs.

 *

 * @package    moodlecore

 * @subpackage blog

 * @copyright  2009 Nicolas Connault

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

defined('MOODLE_INTERNAL') || die();

require_once($CFG->libdir . '/filelib.php');

/**

 * Blog_entry class. Represents an entry in a user's blog. Contains all methods for managing this entry.

 * This class does not contain any HTML-generating code. See blog_listing sub-classes for such code.

 * This class follows the Object Relational Mapping technique, its member variables being mapped to

 * the fields of the post table.

 *

 * @package    moodlecore

 * @subpackage blog

 * @copyright  2009 Nicolas Connault

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class blog_entry implements renderable {

    // Public Database fields.

    public $id;

    public $userid;

    public $subject;

    public $summary;

    public $rating = 0;

    public $attachment;

    public $publishstate;

    // Locked Database fields (Don't touch these).

    public $courseid = 0;

    public $groupid = 0;

    public $module = 'blog';

    public $moduleid = 0;

    public $coursemoduleid = 0;

    public $content;

    public $format = 1;

    public $uniquehash = '';

    public $lastmodified;

    public $created;

    public $usermodified;

    // Other class variables.

    public $form;

    public $tags = array();

    /** @var StdClass Data needed to render the entry */

    public $renderable;

    /** @var string summary format. */

    public string $summaryformat;

    /** @var array summary editor. */

    public array $summary_editor;

    /** @var string */

    public $summarytrust;

    /** @var int course associated with the blog post. */

    public $courseassoc;

    /** @var string module associated with the blog post. */

    public $modassoc;

    /** @var mixed attachment. */

    public $attachment_filemanager;

    /** @var string blog post body. */

    public $body;

    /** @var int attachment entry id. */

    public $entryid;

    /** @var string|null submit button. */

    public $submitbutton;

    /** @var string|null user alias. */

    public $useridalias;

    /** @var string|null user picture. */

    public $picture;

    /** @var string|null user first name. */

    public $firstname;

    /** @var string|null user middle name. */

    public $middlename;

    /** @var string|null user last name. */

    public $lastname;

    /** @var string|null user first name phonetic. */

    public $firstnamephonetic;

    /** @var string|null user last name phonetic. */

    public $lastnamephonetic;

    /** @var string|null user alternate name. */

    public $alternatename;

    /** @var string|null user email address. */

    public $email;

    /** @var string */

    public $action;

    /** @var string|null user picture description. */

    public $imagealt;

    /** @var int module instance id. */

    public $modid;

    /**

     * Constructor. If given an id, will fetch the corresponding record from the DB.

     *

     * @param mixed $idorparams A blog entry id if INT, or data for a new entry if array

     * @throws moodle_exception

     */

    public function __construct($id=null, $params=null, $form=null) {

        global $DB, $PAGE, $CFG;

        if (!empty($id)) {

            $object = $DB->get_record('post', array('id' => $id), '*', MUST_EXIST);

            foreach ($object as $var => $val) {

                $this->$var = $val;

            }

        } else if (!empty($params) && (is_array($params) || is_object($params))) {

            foreach ($params as $var => $val) {

                $this->$var = $val;

            }

        }

        if (!empty($CFG->useblogassociations)) {

            $associations = $DB->get_records('blog_association', array('blogid' => $this->id));

            foreach ($associations as $association) {

                $context = context::instance_by_id($association->contextid);

                if ($context->contextlevel == CONTEXT_COURSE) {

                    $this->courseassoc = $association->contextid;

                } else if ($context->contextlevel == CONTEXT_MODULE) {

                    $this->modassoc = $association->contextid;

                }

            }

        }

        $this->form = $form;

    }

    /**

     * Gets the required data to print the entry

     */

    public function prepare_render() {

        global $DB, $CFG, $PAGE;

        $this->renderable = new StdClass();

        $this->renderable->user = $DB->get_record('user', array('id' => $this->userid));

        // Entry comments.

        if (!empty($CFG->usecomments) and $CFG->blogusecomments) {

            require_once($CFG->dirroot . '/comment/lib.php');

            $cmt = new stdClass();

            $cmt->context = context_user::instance($this->userid);

            $cmt->courseid = $PAGE->course->id;

            $cmt->area = 'format_blog';

            $cmt->itemid = $this->id;

            $cmt->showcount = $CFG->blogshowcommentscount;

            $cmt->component = 'blog';

            $this->renderable->comment = new comment($cmt);

        }

        $this->summary = file_rewrite_pluginfile_urls($this->summary, 'pluginfile.php', SYSCONTEXTID, 'blog', 'post', $this->id);

        // External blog link.

        if ($this->uniquehash && $this->content) {

            if ($externalblog = $DB->get_record('blog_external', array('id' => $this->content))) {

                $urlparts = parse_url($externalblog->url);

                $this->renderable->externalblogtext = get_string('retrievedfrom', 'blog') . get_string('labelsep', 'langconfig');

                $this->renderable->externalblogtext .= html_writer::link($urlparts['scheme'] . '://' . $urlparts['host'],

                                                                         $externalblog->name);

            }

        }

        // Retrieve associations.

        $this->renderable->unassociatedentry = false;

        if (!empty($CFG->useblogassociations)) {

            // Adding the entry associations data.

            if ($associations = $associations = $DB->get_records('blog_association', array('blogid' => $this->id))) {

                // Check to see if the entry is unassociated with group/course level access.

                if ($this->publishstate == 'group' || $this->publishstate == 'course') {

                    $this->renderable->unassociatedentry = true;

                }

                foreach ($associations as $key => $assocrec) {

                    if (!$context = context::instance_by_id($assocrec->contextid, IGNORE_MISSING)) {

                        unset($associations[$key]);

                        continue;

                    }

                    // The renderer will need the contextlevel of the association.

                    $associations[$key]->contextlevel = $context->contextlevel;

                    // Course associations.

                    if ($context->contextlevel == CONTEXT_COURSE) {

                        // TODO: performance!!!!

                        $instancename = $DB->get_field('course', 'shortname', array('id' => $context->instanceid));

                        $associations[$key]->url = $assocurl = new moodle_url('/course/view.php',

                                                                              array('id' => $context->instanceid));

                        $associations[$key]->text = $instancename;

                        $associations[$key]->icon = new pix_icon('i/course', $associations[$key]->text);

                    }

                    // Mod associations.

                    if ($context->contextlevel == CONTEXT_MODULE) {

                        // Getting the activity type and the activity instance id.

                        $sql = 'SELECT cm.instance, m.name FROM {course_modules} cm

                                  JOIN {modules} m ON m.id = cm.module

                                 WHERE cm.id = :cmid';

                        $modinfo = $DB->get_record_sql($sql, array('cmid' => $context->instanceid));

                        // TODO: performance!!!!

                        $instancename = $DB->get_field($modinfo->name, 'name', array('id' => $modinfo->instance));

                        $associations[$key]->type = get_string('modulename', $modinfo->name);

                        $associations[$key]->url = new moodle_url('/mod/' . $modinfo->name . '/view.php',

                                                                  array('id' => $context->instanceid));

                        $associations[$key]->text = $instancename;

                        $associations[$key]->icon = new pix_icon('icon', $associations[$key]->text, $modinfo->name);

                    }

                }

            }

            $this->renderable->blogassociations = $associations;

        }

        // Entry attachments.

        $this->renderable->attachments = $this->get_attachments();

        $this->renderable->usercanedit = blog_user_can_edit_entry($this);

    }

    /**

     * Gets the entry attachments list

     * @return array List of blog_entry_attachment instances

     */

    public function get_attachments() {

        global $CFG;

        require_once($CFG->libdir.'/filelib.php');

        $syscontext = context_system::instance();

        $fs = get_file_storage();

        $files = $fs->get_area_files($syscontext->id, 'blog', 'attachment', $this->id);

        // Adding a blog_entry_attachment for each non-directory file.

        $attachments = array();

        foreach ($files as $file) {

            if ($file->is_directory()) {

                continue;

            }

            $attachments[] = new blog_entry_attachment($file, $this->id);

        }

        return $attachments;

    }

    /**

     * Inserts this entry in the database. Access control checks must be done by calling code.

     *

     * @param mform $form Used for attachments

     * @return void

     */

    public function process_attachment($form) {

        $this->form = $form;

    }

    /**

     * Inserts this entry in the database. Access control checks must be done by calling code.

     * TODO Set the publishstate correctly

     * @return void

     */

    public function add() {

        global $CFG, $USER, $DB;

        unset($this->id);

        $this->module       = 'blog';

        $this->userid       = (empty($this->userid)) ? $USER->id : $this->userid;

        $this->lastmodified = time();

        $this->created      = time();

        // Insert the new blog entry.

        $this->id = $DB->insert_record('post', $this);

        if (!empty($CFG->useblogassociations)) {

            $this->add_associations();

        }

        core_tag_tag::set_item_tags('core', 'post', $this->id, context_user::instance($this->userid), $this->tags);

        // Trigger an event for the new entry.

        $event = \core\event\blog_entry_created::create(array(

            'objectid'      => $this->id,

            'relateduserid' => $this->userid

        ));

        $event->set_blog_entry($this);

        $event->trigger();

    }

    /**

     * Updates this entry in the database. Access control checks must be done by calling code.

     *

     * @param array       $params            Entry parameters.

     * @param moodleform  $form              Used for attachments.

     * @param array       $summaryoptions    Summary options.

     * @param array       $attachmentoptions Attachment options.

     *

     * @return void

     */

    public function edit($params=array(), $form=null, $summaryoptions=array(), $attachmentoptions=array()) {

        global $CFG, $DB;

        $sitecontext = context_system::instance();

        $entry = $this;

        $this->form = $form;

        foreach ($params as $var => $val) {

            $entry->$var = $val;

        }

        $entry = file_postupdate_standard_editor($entry, 'summary', $summaryoptions, $sitecontext, 'blog', 'post', $entry->id);

        $entry = file_postupdate_standard_filemanager($entry,

                                                      'attachment',

                                                      $attachmentoptions,

                                                      $sitecontext,

                                                      'blog',

                                                      'attachment',

                                                      $entry->id);

        if (!empty($CFG->useblogassociations)) {

            $entry->add_associations();

        }

        $entry->lastmodified = time();

        // Update record.

        $DB->update_record('post', $entry);

        core_tag_tag::set_item_tags('core', 'post', $entry->id, context_user::instance($this->userid), $entry->tags);

        $event = \core\event\blog_entry_updated::create(array(

            'objectid'      => $entry->id,

            'relateduserid' => $entry->userid

        ));

        $event->set_blog_entry($entry);

        $event->trigger();

    }

    /**

     * Deletes this entry from the database. Access control checks must be done by calling code.

     *

     * @return void

     */

    public function delete() {

        global $DB;

        $this->delete_attachments();

        $this->remove_associations();

        // Get record to pass onto the event.

        $record = $DB->get_record('post', array('id' => $this->id));

        $DB->delete_records('post', array('id' => $this->id));

        core_tag_tag::remove_all_item_tags('core', 'post', $this->id);

        $event = \core\event\blog_entry_deleted::create(array(

            'objectid'      => $this->id,

            'relateduserid' => $this->userid

            ));

        $event->add_record_snapshot("post", $record);

        $event->set_blog_entry($this);

        $event->trigger();

    }

    /**

     * Function to add all context associations to an entry.

     *

     * @param string $unused This does nothing, do not use it.

     */

    public function add_associations($unused = null) {

        if ($unused !== null) {

            debugging('Illegal argument used in blog_entry->add_associations()', DEBUG_DEVELOPER);

        }

        $this->remove_associations();

        if (!empty($this->courseassoc)) {

            $this->add_association($this->courseassoc);

        }

        if (!empty($this->modassoc)) {

            $this->add_association($this->modassoc);

        }

    }

    /**

     * Add a single association for a blog entry

     *

     * @param int $contextid - id of context to associate with the blog entry.

     * @param string $unused This does nothing, do not use it.

     */

    public function add_association($contextid, $unused = null) {

        global $DB;

        if ($unused !== null) {

            debugging('Illegal argument used in blog_entry->add_association()', DEBUG_DEVELOPER);

        }

        $assocobject = new StdClass;

        $assocobject->contextid = $contextid;

        $assocobject->blogid = $this->id;

        $id = $DB->insert_record('blog_association', $assocobject);

        // Trigger an association created event.

        $context = context::instance_by_id($contextid);

        $eventparam = array(

            'objectid' => $id,

            'other' => array('associateid' => $context->instanceid, 'subject' => $this->subject, 'blogid' => $this->id),

            'relateduserid' => $this->userid

        );

        if ($context->contextlevel == CONTEXT_COURSE) {

            $eventparam['other']['associatetype'] = 'course';

        } else if ($context->contextlevel == CONTEXT_MODULE) {

            $eventparam['other']['associatetype'] = 'coursemodule';

        }

        $event = \core\event\blog_association_created::create($eventparam);

        $event->trigger();

    }

    /**

     * remove all associations for a blog entry

     *

     * @return void

     */

    public function remove_associations() {

        global $DB;

        $associations = $DB->get_records('blog_association', array('blogid' => $this->id));

        foreach ($associations as $association) {

            // Trigger an association deleted event.

            $context = context::instance_by_id($association->contextid);

            $eventparam = array(

                'objectid' => $this->id,

                'other' => array('subject' => $this->subject, 'blogid' => $this->id),

                'relateduserid' => $this->userid

            );

            $event = \core\event\blog_association_deleted::create($eventparam);

            $event->add_record_snapshot('blog_association', $association);

            $event->trigger();

            // Now remove the association.

            $DB->delete_records('blog_association', array('id' => $association->id));

        }

    }

    /**

     * Deletes all the user files in the attachments area for an entry

     *

     * @return void

     */

    public function delete_attachments() {

        $fs = get_file_storage();

        $fs->delete_area_files(SYSCONTEXTID, 'blog', 'attachment', $this->id);

        $fs->delete_area_files(SYSCONTEXTID, 'blog', 'post', $this->id);

    }

    /**

     * User can edit a blog entry if this is their own blog entry and they have

     * the capability moodle/blog:create, or if they have the capability

     * moodle/blog:manageentries.

     * This also applies to deleting of entries.

     *

     * @param int $userid Optional. If not given, $USER is used

     * @return boolean

     */

    public function can_user_edit($userid=null) {

        global $CFG, $USER;

        if (empty($userid)) {

            $userid = $USER->id;

        }

        $sitecontext = context_system::instance();

        if (has_capability('moodle/blog:manageentries', $sitecontext)) {

            return true; // Can edit any blog entry.

        }

        if ($this->userid == $userid && has_capability('moodle/blog:create', $sitecontext)) {

            return true; // Can edit own when having blog:create capability.

        }

        return false;

    }

    /**

     * Checks to see if a user can view the blogs of another user.

     * Only blog level is checked here, the capabilities are enforced

     * in blog/index.php

     *

     * @param int $targetuserid ID of the user we are checking

     *

     * @return bool

     */

    public function can_user_view($targetuserid) {

        global $CFG, $USER, $DB;

        $sitecontext = context_system::instance();

        if (empty($CFG->enableblogs) || !has_capability('moodle/blog:view', $sitecontext)) {

            return false; // Blog system disabled or user has no blog view capability.

        }

        if (isloggedin() && $USER->id == $targetuserid) {

            return true; // Can view own entries in any case.

        }

        if (has_capability('moodle/blog:manageentries', $sitecontext)) {

            return true; // Can manage all entries.

        }

        // Coming for 1 entry, make sure it's not a draft.

        if ($this->publishstate == 'draft' && !has_capability('moodle/blog:viewdrafts', $sitecontext)) {

            return false;  // Can not view draft of others.

        }

        // Coming for 1 entry, make sure user is logged in, if not a public blog.

        if ($this->publishstate != 'public' && !isloggedin()) {

            return false;

        }

        switch ($CFG->bloglevel) {

            case BLOG_GLOBAL_LEVEL:

                return true;

                break;

            case BLOG_SITE_LEVEL:

                if (isloggedin()) { // Not logged in viewers forbidden.

                    return true;

                }

                return false;

                break;

            case BLOG_USER_LEVEL:

            default:

                $personalcontext = context_user::instance($targetuserid);

                return has_capability('moodle/user:readuserblogs', $personalcontext);

                break;

        }

    }

    /**

     * Use this function to retrieve a list of publish states available for

     * the currently logged in user.

     *

     * @return array This function returns an array ideal for sending to moodles'

     *                choose_from_menu function.

     */

    public static function get_applicable_publish_states() {

        global $CFG;

        $options = array();

        // Everyone gets draft access.

        if ($CFG->bloglevel >= BLOG_USER_LEVEL) {

            $options['draft'] = get_string('publishtonoone', 'blog');

        }

        if ($CFG->bloglevel > BLOG_USER_LEVEL) {

            $options['site'] = get_string('publishtosite', 'blog');

        }

        if ($CFG->bloglevel >= BLOG_GLOBAL_LEVEL) {

            $options['public'] = get_string('publishtoworld', 'blog');

        }

        return $options;

    }

}

/**

 * Abstract Blog_Listing class: used to gather blog entries and output them as listings. One of the subclasses must be used.

 *

 * @package    moodlecore

 * @subpackage blog

 * @copyright  2009 Nicolas Connault

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class blog_listing {

    /**

     * Array of blog_entry objects.

     * @var array $entries

     */

    public $entries = null;

    /**

     * Caches the total number of the entries.

     * @var int

     */

    public $totalentries = null;

    /**

     * An array of blog_filter_* objects

     * @var array $filters

     */

    public $filters = array();

    /**

     * Constructor

     *

     * @param array $filters An associative array of filtername => filterid

     */

    public function __construct($filters=array()) {

        // Unset filters overridden by more specific filters.

        foreach ($filters as $type => $id) {

            if (!empty($type) && !empty($id)) {

                $this->filters[$type] = blog_filter::get_instance($id, $type);

            }

        }

        foreach ($this->filters as $type => $filter) {

            foreach ($filter->overrides as $override) {

                if (array_key_exists($override, $this->filters)) {

                    unset($this->filters[$override]);

                }

            }

        }

    }

    /**

     * Fetches the array of blog entries.

     *

     * @return array

     */

    public function get_entries($start=0, $limit=10) {

        global $DB;

        if ($this->entries === null) {

            if ($sqlarray = $this->get_entry_fetch_sql(false, 'created DESC')) {

                $this->entries = $DB->get_records_sql($sqlarray['sql'], $sqlarray['params'], $start, $limit);

                if (!$start && count($this->entries) < $limit) {

                    $this->totalentries = count($this->entries);

                }

            } else {

                return false;

            }

        }

        return $this->entries;

    }

    /**

     * Finds total number of blog entries

     *

     * @return int

     */

    public function count_entries() {

        global $DB;

        if ($this->totalentries === null) {

            if ($sqlarray = $this->get_entry_fetch_sql(true)) {

                $this->totalentries = $DB->count_records_sql($sqlarray['sql'], $sqlarray['params']);

            } else {

                $this->totalentries = 0;

            }

        }

        return $this->totalentries;

    }

    public function get_entry_fetch_sql($count=false, $sort='lastmodified DESC', $userid = false) {

        global $DB, $USER, $CFG;

        if (!$userid) {

            $userid = $USER->id;

        }

        $userfieldsapi = \core_user\fields::for_userpic();

        $allnamefields = $userfieldsapi->get_sql('u', false, '', 'useridalias', false)->selects;

        // The query used to locate blog entries is complicated.  It will be built from the following components:

        $requiredfields = "p.*, $allnamefields";  // The SELECT clause.

        $tables = array('p' => 'post', 'u' => 'user');   // Components of the FROM clause (table_id => table_name).

        // Components of the WHERE clause (conjunction).

        $conditions = array('u.deleted = 0', 'p.userid = u.id', '(p.module = \'blog\' OR p.module = \'blog_external\')');

        // Build up a clause for permission constraints.

        $params = array();

        // Fix for MDL-9165, use with readuserblogs capability in a user context can read that user's private blogs.

        // Admins can see all blogs regardless of publish states, as described on the help page.

        if (has_capability('moodle/user:readuserblogs', context_system::instance())) {

            // Don't add permission constraints.

        } else if (!empty($this->filters['user'])

                   && has_capability('moodle/user:readuserblogs',

                                     context_user::instance((empty($this->filters['user']->id) ? 0 : $this->filters['user']->id)))) {

            // Don't add permission constraints.

        } else {

            if (isloggedin() and !isguestuser()) {

                // Dont check association records if there aren't any.

                $assocexists = $DB->record_exists('blog_association', array());

                // Begin permission sql clause.

                $permissionsql = '(p.userid = ? ';

                $params[] = $userid;

                if ($CFG->bloglevel >= BLOG_SITE_LEVEL) { // Add permission to view site-level entries.

                    $permissionsql .= " OR p.publishstate = 'site' ";

                }

                if ($CFG->bloglevel >= BLOG_GLOBAL_LEVEL) { // Add permission to view global entries.

                    $permissionsql .= " OR p.publishstate = 'public' ";

                }

                $permissionsql .= ') ';   // Close permissions sql clause.

            } else {  // Default is access to public entries.

                $permissionsql = "p.publishstate = 'public'";

            }

            $conditions[] = $permissionsql;  // Add permission constraints.

        }

        foreach ($this->filters as $type => $blogfilter) {

            $conditions = array_merge($conditions, $blogfilter->conditions);

            $params = array_merge($params, $blogfilter->params);

            $tables = array_merge($tables, $blogfilter->tables);

        }

        $tablessql = '';  // Build up the FROM clause.

        foreach ($tables as $tablename => $table) {

            $tablessql .= ($tablessql ? ', ' : '').'{'.$table.'} '.$tablename;

        }

        $sql = ($count) ? 'SELECT COUNT(*)' : 'SELECT ' . $requiredfields;

        $sql .= " FROM $tablessql WHERE " . implode(' AND ', $conditions);

        $sql .= ($count) ? '' : " ORDER BY $sort";

        return array('sql' => $sql, 'params' => $params);

    }

    /**

     * Outputs all the blog entries aggregated by this blog listing.

     *

     * @return void

     */

    public function print_entries() {

        global $CFG, $USER, $DB, $OUTPUT, $PAGE;

        $sitecontext = context_system::instance();

        // Blog renderer.

        $output = $PAGE->get_renderer('blog');

        $page  = optional_param('blogpage', 0, PARAM_INT);

        $limit = optional_param('limit', get_user_preferences('blogpagesize', 10), PARAM_INT);

        $start = $page * $limit;

        $morelink = '<br />&nbsp;&nbsp;';

        $entries = $this->get_entries($start, $limit);

        $totalentries = $this->count_entries();

        $pagingbar = new paging_bar($totalentries, $page, $limit, $this->get_baseurl());

        $pagingbar->pagevar = 'blogpage';

        $blogheaders = blog_get_headers();

        echo $OUTPUT->render($pagingbar);

        if (has_capability('moodle/blog:create', $sitecontext)) {

            // The user's blog is enabled and they are viewing their own blog.

            $userid = optional_param('userid', null, PARAM_INT);

            if (empty($userid) || (!empty($userid) && $userid == $USER->id)) {

                $courseid = optional_param('courseid', null, PARAM_INT);

                $modid = optional_param('modid', null, PARAM_INT);

                $addurl = new moodle_url("$CFG->wwwroot/blog/edit.php");

                $urlparams = array('action' => 'add',

                                   'userid' => $userid,

                                   'courseid' => $courseid,

                                   'groupid' => optional_param('groupid', null, PARAM_INT),

                                   'modid' => $modid,

                                   'tagid' => optional_param('tagid', null, PARAM_INT),

                                   'tag' => optional_param('tag', null, PARAM_INT),

                                   'search' => optional_param('search', null, PARAM_INT));

                $urlparams = array_filter($urlparams);

                $addurl->params($urlparams);

                $addlink = '<div class="addbloglink">';

                $addlink .= '<a href="'.$addurl->out().'">'. $blogheaders['stradd'].'</a>';

                $addlink .= '</div>';

                echo $addlink;

            }

        }

        if ($entries) {

            $count = 0;

            foreach ($entries as $entry) {

                $blogentry = new blog_entry(null, $entry);

                // Get the required blog entry data to render it.

                $blogentry->prepare_render();

                echo $output->render($blogentry);

                $count++;

            }

            echo $OUTPUT->render($pagingbar);

            if (!$count) {

                print '<br /><div style="text-align:center">'. get_string('noentriesyet', 'blog') .'</div><br />';

            }

            print $morelink.'<br />'."\n";

            return;

        }

    }

    // Find the base url from $_GET variables, for print_paging_bar.

    public function get_baseurl() {

        $getcopy  = $_GET;

        unset($getcopy['blogpage']);

        if (!empty($getcopy)) {

            $first = false;

            $querystring = '';

            foreach ($getcopy as $var => $val) {

                if (!$first) {

                    $first = true;

                    $querystring .= "?$var=$val";

                } else {

                    $querystring .= '&'.$var.'='.$val;

                    $hasparam = true;

                }

            }

        } else {

            $querystring = '?';

        }

        return strip_querystring(qualified_me()) . $querystring;

    }

}

/**

 * Abstract class for blog_filter objects.

 * A set of core filters are implemented here. To write new filters, you need to subclass

 * blog_filter and give it the name of the type you want (for example, blog_filter_entry).

 * The blog_filter abstract class will automatically use it when the filter is added to the

 * URL. The first parameter of the constructor is the ID of your filter, but it can be a string

 * or have any other meaning you wish it to have. The second parameter is called $type and is

 * used as a sub-type for filters that have a very similar implementation (see blog_filter_context for an example)

 */

abstract class blog_filter {

    /**

     * An array of strings representing the available filter types for each blog_filter.

     * @var array $availabletypes

     */

    public $availabletypes = array();

    /**

     * The type of filter (for example, types of blog_filter_context are site, course and module)

     * @var string $type

     */

    public $type;

    /**

     * The unique ID for a filter's associated record

     * @var int $id

     */

    public $id;

    /**

     * An array of table aliases that are used in the WHERE conditions

     * @var array $tables

     */

    public $tables = array();

    /**

     * An array of WHERE conditions

     * @var array $conditions

     */

    public $conditions = array();

    /**

     * An array of SQL params

     * @var array $params

     */

    public $params = array();

    /**

     * An array of filter types which this particular filter type overrides: their conditions will not be evaluated

     */

    public $overrides = array();

    public function __construct($id, $type=null) {

        $this->id = $id;

        $this->type = $type;

    }

    /**

     * TODO This is poor design. A parent class should not know anything about its children.

     * The default case helps to resolve this design issue

     */

    public static function get_instance($id, $type) {

        switch ($type) {

            case 'site':

            case 'course':

            case 'module':

                return new blog_filter_context($id, $type);

                break;

            case 'group':

            case 'user':

                return new blog_filter_user($id, $type);

                break;

            case 'tag':

                return new blog_filter_tag($id);

                break;

            default:

                $classname = "blog_filter_$type";

                if (class_exists($classname)) {

                    return new $classname($id, $type);

                }

        }

    }

}

/**

 * This filter defines the context level of the blog entries being searched: site, course, module

 */

class blog_filter_context extends blog_filter {

    /**

     * Constructor

     *

     * @param string $type

     * @param int    $id

     */

    public function __construct($id=null, $type='site') {

        global $SITE, $CFG, $DB;

        if (empty($id)) {

            $this->type = 'site';

        } else {

            $this->id = $id;

            $this->type = $type;

        }

        $this->availabletypes = array('site' => get_string('site'),

                                      'course' => get_string('course'),

                                      'module' => get_string('activity'),

                                      'context' => get_string('coresystem'));

        switch ($this->type) {

            case 'course': // Careful of site course!

                // Ignore course filter if blog associations are not enabled.

                if ($this->id != $SITE->id && !empty($CFG->useblogassociations)) {

                    $this->overrides = array('site', 'context');

                    $context = context_course::instance($this->id);

                    $this->tables['ba'] = 'blog_association';

                    $this->conditions[] = 'p.id = ba.blogid';

                    $this->conditions[] = 'ba.contextid = '.$context->id;

                    break;

                } else {

                    // We are dealing with the site course, do not break from the current case.

                }

            case 'site':

                // No special constraints.