+<?php
+/*
+ * Name: Language Filter
+ * Version: 0.1
+ * Description: Filters out postings in languages not spoken by the users
+ * Author: Tobias Diekershoff <https://f.diekershoff.de/u/tobias>
+ * License: MIT
+ */
+
+require_once('library/langdet/Text/LanguageDetect.php');
+
+/* Define the hooks we want to use
+ * that is, we have settings, we need to save the settings and we want
+ * to modify the content of a posting when friendica prepares it.
+ */
+function langfilter_install() {
+ register_hook('prepare_body', 'addon/langfilter/langfilter.php', 'langfilter_prepare_body', 10);
+ register_hook('plugin_settings', 'addon/langfilter/langfilter.php', 'langfilter_addon_settings');
+ register_hook('plugin_settings_post', 'addon/langfilter/langfilter.php', 'langfilter_addon_settings_post');
+}
+function langfilter_uninstall() {
+ unregister_hook('prepare_body', 'addon/langfilter/langfilter.php', 'langfilter_prepare_body');
+ unregister_hook('plugin_settings', 'addon/langfilter/langfilter.php', 'langfilter_addon_settings');
+ unregister_hook('plugin_settings_post', 'addon/langfilter/langfilter.php', 'langfilter_addon_settings_post');
+}
+
+/* The settings
+ * 1st check if somebody logged in is calling
+ * 2nd get the current settings
+ * 3rd parse a SMARTY3 template, replacing some translateable strings for the form
+ */
+function langfilter_addon_settings(&$a,&$s) {
+ if(! local_user())
+ return;
+
+ $enable_checked = (intval(get_pconfig(local_user(),'langfilter','disable')) ? '' : ' checked="checked" ');
+ $languages = get_pconfig(local_user(),'langfilter','languages');
+ if(! $languages)
+ $languages = 'en,de,fr,it,es';
+
+ $t = get_markup_template("settings.tpl", "addon/langfilter/" );
+ $s .= replace_macros ($t, array(
+ '$title' => t("Language Filter"),
+ '$intro' => t ('This addon tries to identify the language of a postings. If it does not match any language spoken by you (see below) the posting will be collapsed. Remember detecting the language is not perfect, especially with short postings.'),
+ '$enabled' => array('langfilter_enable', t('Use the language filter'), $enable_checked, ''),
+ '$regex' => t('Use /expression/ to provide regular expressions'),
+ '$languages' => array('langfilter_languages', t('I speak'), $languages, t('List of abbreviations for languages you speak, comma seperated. For excample "de,it".') ),
+ '$submit' => t('Save Settings'),
+ ));
+
+ return;
+}
+/* Save the settings
+ * 1st check it's a logged in user calling
+ * 2nd check the langfilter form is to be saved
+ * 3rd save the settings to the DB for later usage
+ */
+function langfilter_addon_settings_post(&$a,&$b) {
+ if(! local_user())
+ return;
+
+ if($_POST['langfilter-settings-submit']) {
+ set_pconfig(local_user(),'langfilter','languages',trim($_POST['langfilter_languages']));
+ $enable = ((x($_POST,'langfilter_enable')) ? intval($_POST['langfilter_enable']) : 0);
+ $disable = 1-$enable;
+ set_pconfig(local_user(),'langfilter','disable', $disable);
+ info( t('Language Filter Settings saved.') . EOL);
+ }
+}
+/* Actually filter postings by their language
+ * 1st check if the user wants to filter postings
+ * 2nd get the user settings which languages shall be not filtered out
+ * 3rd determine the language of a posting
+ * 4th if the determined language does not fit to the spoken languages
+ * of the user, then collapse the posting, but provide a link to
+ * expand it again.
+ */
+function langfilter_prepare_body(&$a,&$b) {
+ if(get_pconfig(local_user(),'langfilter','disable'))
+ return;
+
+ if(local_user()) {
+ $langs = get_pconfig(local_user(),'langfilter','languages');
+ }
+ if($langs) {
+ $arr = explode(',',$langs);
+ } else {
+ return;
+ }
+
+ $found = false;
+ $l = new Text_LanguageDetect;
+ $l->_name_mode = 2; // two letter codes
+ $l->_threshold = 600; // make it a bit harder to be confident with a lng
+ // IOW make it more possible that lng is correct
+ $lng = $l->detectSimple($b['html']);
+ if ($lng==null)
+ return;
+ if (! in_array($lng, $arr))
+ $found = true;
+ if ($lng==null)
+ $found = false;
+
+ if($found) {
+ $rnd = random_string(8);
+ $b['html'] = '<div id="langfilter-wrap-' . $rnd . '" class="fakelink" onclick=openClose(\'langfilter-' . $rnd . '\'); >' . sprintf( t('unspoken language %s - Click to open/close'),$lng ) . '</div><div id="langfilter-' . $rnd . '" style="display: none; " >' . $b['html'] . '</div>';
+ }
+}
+?>