What is the sum of 2 and 9? Version: 2.2 Author: Michael Woehrer Author URI: http://sw-guide.de/ */ /* ---------------------------------------------------------------------------- ____________________________________________________ | | | Math Comment Spam Protection | | © Michael Woehrer | |____________________________________________________| © Copyright 2006-2007 Michael Woehrer (michael dot woehrer at gmail dot com) 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. ---------------------------------------------------------------------------- ACKNOWLEDGEMENTS: - Thanks to Steven Herod (http://www.herod.net/) for his plugin "Did You Pass Math?". I took his idea and extended/improved it by writing a plugin on my own. ---------------------------------------------------------------------------- INSTALLATION, USAGE: Visit the plugin's homepage. ---------------------------------------------------------------------------- */ # Determine installation path: will be under wp-content/plugins or under a subdir of /plugins/ $mcsp_info['install_dir'] = ABSPATH . 'wp-content/plugins'; if ( basename(dirname(__FILE__)) != 'plugins' ) $mcsp_info['install_dir'] .= '/' . basename(dirname(__FILE__)); # Include the class and create object if ( !class_exists('MathCheck') ) include_once($mcsp_info['install_dir'] . '/math-comment-spam-protection.classes.php'); $mcsp_MathCheckObj = new MathCheck; # Get settings $mcsp_opt = get_option('plugin_mathcommentspamprotection'); /******************************************************************************* * Let's use wp_nonce to secure the forms. * Source: http://michaeldaw.org/papers/securing_wp_plugins/ * Code is being implemented at different locations, always commented as "### SECURING FORMS ###" ******************************************************************************/ if ( !function_exists('wp_nonce_field') ) { function mcsp_nonce_field($action = -1) { return; } $mcsp_nonce = -1; } else { function mcsp_nonce_field($action = -1) { return wp_nonce_field($action); } $mcsp_nonce = 'mcsp-update-key'; } /******************************************************************************* * Generate math question ******************************************************************************/ function math_comment_spam_protection() { global $mcsp_MathCheckObj, $mcsp_opt; // Set class options $mcsp_MathCheckObj->opt['input_numbers'] = $mcsp_opt['mcsp_opt_numbers']; // Generate numbers to be displayed and result $mcsp_MathCheckObj->GenerateValues(); $mcsp_info['operand1'] = $mcsp_MathCheckObj->info['operand1']; $mcsp_info['operand2'] = $mcsp_MathCheckObj->info['operand2']; $mcsp_info['result'] = $mcsp_MathCheckObj->info['result']; return $mcsp_info; } /******************************************************************************* * Input validation. ******************************************************************************/ function mcsp_check_input($comment_data) { global $mcsp_MathCheckObj, $user_ID, $mcsp_opt; if ( ( !isset($user_ID) ) && ( $comment_data['comment_type'] == '' ) ) { // Do not check if the user is registered & do not check trackbacks/pingbacks // Get actual result $actual_result = $_POST[ $mcsp_opt['mcsp_opt_fieldname_mathresult'] ]; // Get value user has entered $value_entered = $_POST[ $mcsp_opt['mcsp_opt_fieldname_useranswer'] ]; // Get input validation result $result = $mcsp_MathCheckObj->InputValidation($actual_result, $value_entered); // DIE if there was an error. Apply filter for security reasons (strip JS code, etc.) switch ($result) { case 'No answer': mcsp_aux_die( apply_filters('pre_comment_content', stripslashes($mcsp_opt['mcsp_opt_msg_no_answer'])) ); break; case 'Wrong answer': mcsp_aux_die( apply_filters('pre_comment_content', stripslashes($mcsp_opt['mcsp_opt_msg_wrong_answer'])) ); break; } } return $comment_data; } /******************************************************************************* * Apply plugin ******************************************************************************/ add_filter('preprocess_comment', 'mcsp_check_input', 0); ################################################################################################################################## /******************************************************************************* * Admin *******************************************************************************/ // Add admin menu function mcsp_add_options_to_admin() { if (function_exists('add_options_page')) { add_options_page('Math Comment Spam', 'Math Comment Spam', 8, basename(__FILE__), 'mcsp_options_subpanel'); } } // This will add the new item, 'Math Comment Spam', to the Options menu. function mcsp_options_subpanel() { /* Lets add some default options if they don't exist If an option with the specified name already exists, no changes are made to its value or to the database as a whole. add_option() can only add options, not alter them.*/ $tmp_noanswer = '

Error: Please press the back button and fill the required field for spam protection.

'; $tmp_wronganswer = '

Error: You have entered the wrong sum in the spam protection field.
Press the back button and try again.

'; $optionarray_def = array( 'mcsp_opt_numbers' => '1~1, 2~2, 3~3, 4~4, 5~5, 6~6, 7~7, 8~8, 9~9, 10~10', 'mcsp_opt_msg_no_answer' => $tmp_noanswer, 'mcsp_opt_msg_wrong_answer' => $tmp_wronganswer, 'mcsp_opt_fieldname_useranswer' => 'mcspvalue', 'mcsp_opt_fieldname_mathresult' => 'mcspinfo', ); add_option('plugin_mathcommentspamprotection', $optionarray_def, 'Math Comment Spam Protection Plugin Options'); /* Check form submission and update options if no error occurred */ if (isset($_POST['submit']) ) { ### SECURING FORMS ### if ( function_exists('current_user_can') && !current_user_can('manage_options') ) die(__('Cheatin’ uh?')); check_admin_referer( $mcsp_nonce ); ### SECURING FORMS ### $optionarray_update = array ( 'mcsp_opt_numbers' => mcsp_aux_numbers_input_formatting($_POST['mcsp_opt_numbers']), 'mcsp_opt_msg_no_answer' => $_POST['mcsp_opt_msg_no_answer'], 'mcsp_opt_msg_wrong_answer' => $_POST['mcsp_opt_msg_wrong_answer'], 'mcsp_opt_fieldname_useranswer' => mcsp_aux_fieldname_formatting($_POST['mcsp_opt_fieldname_useranswer']), 'mcsp_opt_fieldname_mathresult' => mcsp_aux_fieldname_formatting($_POST['mcsp_opt_fieldname_mathresult']) ); update_option('plugin_mathcommentspamprotection', $optionarray_update); } /* Get options */ $optionarray_def = get_option('plugin_mathcommentspamprotection'); ?>

Math Comment Spam Protection Options

For details, visit the plugin's homepage.

Used Operands

Enter the numbers to be used. Use the number on the left side, tilde (~) as separator and then the term to display. Separate values with comma (,).
Examples:
 - 1~one, 2~two, 3~three, 4~four, 5~five, 6~six, 7~seven, 8~eight, 9~nine, 10~ten
 - 1~1, 2~2, 3~3, 4~4, 5~5, 6~6, 7~7, 8~8, 9~9, 10~10

Field Names




Error Messages

Error message being displayed in case of no answer (empty field) / not entered a number:

Error message being displayed in case of a wrong answer:

© Copyright 2006-2007  Michael Wöhrer