/* Extract the scroll tracking options from the database */

$options = wpan_get_options ();

$ga_tracker = isset ( $options ['tracker_name'] ) ? $options ['tracker_name'] : '';

$pixel_threshold = isset ( $options['pixel_threshold'] ) ? $options['pixel_threshold'] : '';

$time_threshold = isset ( $options['time_threshold'] ) ? $options['time_threshold'] : '';

$custom_dimension_scroll_tracking = isset ( $options['custom_dimension_scroll_tracking'] ) ? $options['custom_dimension_scroll_tracking'] : '';

$debug = isset ( $options['debug'] ) ? $options['debug'] : '';

/* Script path & url */

$script_path = WPAN_PLUGIN_DIR . 'js/scroll_tracking.js';

$script_url = WPAN_PLUGIN_URL . 'js/scroll_tracking.js';

/* Add the timestamp as a query string to the script, in order to reload

automatically the script when it is changed rather than using the cached

version (see http://stackoverflow.com/a/14536240/2972183) */

$script_versioned = $script_url . '?ver=' . filemtime($script_path);

/* Load the imagesLoaded javascript library to ensure that scroll

tracking works properly with image-rich pages.

TODO: we should use wp_enqueue() here. */

echo "<script src='https://npmcdn.com/imagesloaded@4.1/imagesloaded.pkgd.js' defer='defer'></script>\n";

/* Load the script.

TODO: we should use wp_enqueue() here. */

echo "<script src='$script_versioned' "

. "gaTracker='$ga_tracker' "

. "timeThreshold='$time_threshold' "

. "pixelThreshold='$pixel_threshold' "

. "customDimension='$custom_dimension_scroll_tracking' "

. "debug='$debug' "

. "defer='defer'"

. "> "

. "</script>\n";