gnu-social/actions/tag.php

<?php
/*
 * Laconica - a distributed open-source microblogging tool
 * Copyright (C) 2008, Controlez-Vous, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

if (!defined('LACONICA')) { exit(1); }

require_once(INSTALLDIR.'/actions/showstream.php');
define('TAGS_PER_PAGE', 100);

class TagAction extends StreamAction {

    function handle($args) {

        parent::handle($args);

        # Looks like we're good; show the header

        if (isset($args['tag']) && $args['tag']) {
            $tag = $args['tag'];
            common_show_header(sprintf(_("Notices tagged with %s"), $tag),
                               array($this, 'show_header'), $tag,
                               array($this, 'show_top'));
            $this->show_notices($tag);
        } else {
            common_show_header(_("Tags"),
                               array($this, 'show_header'), '',
                               array($this, 'show_top'));
            $this->show_tags();
        }

        common_show_footer();
    }

    function show_header($tag = false) {
        if ($tag) {
            common_element('link', array('rel' => 'alternate',
                                         'href' => common_local_url('tagrss', array('tag' => $tag)),
                                         'type' => 'application/rss+xml',
                                         'title' => sprintf(_('Feed for tag %s'), $tag)));
        }
    }

    function get_instructions() {
        return _('Showing most popular tags from the last week');
    }

    function show_top($tag = false) {
        if (!$tag) {
            $instr = $this->get_instructions();
            $output = common_markup_to_html($instr);
            common_element_start('div', 'instructions');
            common_raw($output);
            common_element_end('div');
            $this->public_views_menu();
        }
        else {
            $this->show_feeds_list(array(0=>array('href'=>common_local_url('tagrss'),
                                                  'type' => 'rss',
                                                  'version' => 'RSS 1.0',
                                                  'item' => 'tagrss')));
        }
    }

    function show_tags()
    {
        # This should probably be cached rather than recalculated
        $tags = DB_DataObject::factory('Notice_tag');

        #Need to clear the selection and then only re-add the field
        #we are grouping by, otherwise it's not a valid 'group by'
        #even though MySQL seems to let it slide...
        $tags->selectAdd();
        $tags->selectAdd('tag');

        #Add the aggregated columns...
        $tags->selectAdd('max(notice_id) as last_notice_id');
        if(common_config('db','type')=='pgsql') {
            $calc='sum(exp(-extract(epoch from (now()-created))/%s)) as weight';
        } else {
            $calc='sum(exp(-(now() - created)/%s)) as weight';
        }
        $tags->selectAdd(sprintf($calc, common_config('tag', 'dropoff')));
        $tags->groupBy('tag');
        $tags->orderBy('weight DESC');

        # $tags->whereAdd('created > "' . strftime('%Y-%m-%d %H:%M:%S', strtotime('-1 MONTH')) . '"');

        $tags->limit(TAGS_PER_PAGE);

        $cnt = $tags->find();

        if ($cnt > 0) {
            common_element_start('p', 'tagcloud');

            $tw = array();
            $sum = 0;
            while ($tags->fetch()) {
                $tw[$tags->tag] = $tags->weight;
                $sum += $tags->weight;
            }

            ksort($tw);

            foreach ($tw as $tag => $weight) {
                $this->show_tag($tag, $weight, $weight/$sum);
            }

            common_element_end('p');
        }
    }

    function show_tag($tag, $weight, $relative) {

        # XXX: these should probably tune to the size of the site
        if ($relative > 0.1) {
            $cls =  'largest';
        } else if ($relative > 0.05) {
            $cls = 'verylarge';
        } else if ($relative > 0.02) {
            $cls = 'large';
        } else if ($relative > 0.01) {
            $cls = 'medium';
        } else if ($relative > 0.005) {
            $cls = 'small';
        } else if ($relative > 0.002) {
            $cls = 'verysmall';
        } else {
            $cls = 'smallest';
        }

        common_element('a', array('class' => "$cls weight-$weight relative-$relative",
                                  'href' => common_local_url('tag', array('tag' => $tag))),
                       $tag);
        common_text(' ');
    }

    function show_notices($tag) {

        $cnt = 0;

        $page = ($this->arg('page')) ? ($this->arg('page')+0) : 1;

        $notice = Notice_tag::getStream($tag, (($page-1)*NOTICES_PER_PAGE), NOTICES_PER_PAGE + 1);

        $cnt = $this->show_notice_list($notice);

        common_pagination($page > 1, $cnt > NOTICES_PER_PAGE,
                          $page, 'tag', array('tag' => $tag));
    }
}