Basic Google Analytics

basic-google-analytics.php

<?php
/*
Plugin Name: Basic Google Analytics
Plugin URI: trepmal.com
Description: Adds very basic Google Analytics code. Need complex tracking? This isn't for you.
Version: 1
Author: Kailey Lampert
Author URI: kaileylampert.com
*/

$basic_google_analytics = new Basic_Google_Analytics();

class Basic_Google_Analytics {

    function __construct( ) {
        add_filter( 'plugin_action_links_'. plugin_basename( __FILE__ ), array( $this, 'plugin_action_links' ), 10, 4 );
        add_action( 'admin_init' ,                                       array( $this, 'admin_init' ) );
        add_action( 'wp_head',                                           array(  $this, 'wp_head' ) );
    }

    function plugin_action_links( $actions, $plugin_file, $plugin_data, $context ) {
        if ( is_plugin_active( $plugin_file ) ) {
            $actions[] = '<a href="' . admin_url('options-general.php#bga-google_analytics_id') . '">' . __( 'Setup', 'basic-google-analytics' ) . '</a>';
        }
        return $actions;
    }

    function admin_init() {
        register_setting( 'general', 'bga-google_analytics_id', array( $this, 'sanitize_validate' ) );
        add_settings_field( 'bga-google_analytics_id', '<label for="bga-google_analytics_id">' . __( 'Google Analytics ID', 'basic-google-analytics' ) . '</label>' , array( $this, 'fields_html') , 'general' );
    }

    function fields_html() {
        $ga_id = esc_attr( get_option( 'bga-google_analytics_id', '' ) );
        echo "<input type='text' id='bga-google_analytics_id' name='bga-google_analytics_id' value='$ga_id' /><p class='description'>UA-XXXXXXX-YY</p>";
    }

    function sanitize_validate( $given_id ) {
        $saved_id = get_option('bga-google_analytics_id', '');
        $clean_id = strtoupper( strip_tags( trim( $given_id ) ) ); //original, cleaned input

        // if no change, carry on
        if ( $saved_id == $clean_id ) {
            return $saved_id;
        }

        // has the id been removed entirely?
        if ( empty( $clean_id ) ) {
            add_settings_error('', '', __( 'Your Google Analytics ID number has been removed.', 'basic-google-analytics' ), 'updated' );
            return '';
        }

        $almost_ready_id = 'UA-'. trim( $clean_id, 'UA-' ); // account for variance, make sure number is prefixed with "UA-"

        preg_match( '/(UA-\d+-\d+)$/', $almost_ready_id, $match ); // expects: UA-XXXXXXX-YY

        // if empty, then the regex failed to find the correct pattern
        if ( empty( $match ) ) {
            add_settings_error('', '', sprintf( __( '%s is not a valid ID number', 'basic-google-analytics' ), $almost_ready_id ), 'error' );
            return '';
        } else {
            $ready_id = $almost_ready_id;
        }

        // if we've made it this far, we have a good id
        add_settings_error('', '', __( 'Your Google Analytics ID number has been saved.', 'basic-google-analytics' ), 'updated' );
        return $ready_id;
    }

    function wp_head() {
        if ( is_super_admin() ) return; //if not MS, will return true if user can delete other users
        // if ( is_user_logged_in() ) return; //or ignore any logged in user

        $ga_id = get_option( 'bga-google_analytics_id', '' );

        if ( empty( $ga_id ) ) return;
        ?>
<script type="text/javascript">
  var _gaq = _gaq || [];
  _gaq.push(['_setAccount', '<?php echo esc_js( $ga_id ); ?>']);
  _gaq.push(['_trackPageview']);

  (function() {
    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
  })();
</script>
        <?php
    }

}