footnotes/class/settings.php

<?php
/**
 * Includes the Settings class to handle all Plugin settings.
 *
 * @filesource
 * @author Stefan Herndler
 * @since 1.5.0 14.09.14 10:43
 *
 * Edited for:
 * 2.0.4 restore arrow settings  2020-11-02T2115+0100
 * 2.0.7 remove hook the_post  2020-11-06T1342+0100
 * 2.1.0 add read-on button label customization  2020-11-08T2149+0100
 * 2.1.1 fix tooltips on site by alternative  2020-11-11T1819+0100
 * 2.1.1 fix disabling backlink symbol  2020-11-16T2021+0100
 * 2.1.1 fix superscript by making it optional
 * 2.1.1 fix start pages by option to hide ref container
 * 2.1.1 fix ref container by option restoring 3-column layout
 * 2.1.1 fix ref container by option to switch index/symbol  2020-11-16T2022+0100
 * 2.1.1 fix ref container positioning by priority level  2020-11-17T0205+0100
 *
 * Last modified: 2020-11-17T0311+0100
 */


/**
 * The class loads all Settings from each WordPress Settings container.
 * It a Setting is not defined yet, the default value will be used.
 * Each Setting will be validated and sanitized when loaded from the container.
 *
 * @author Stefan Herndler
 * @since 1.5.0
 */
class MCI_Footnotes_Settings {


    /**
     *       SETTINGS CONTAINER KEY DEFINITIONS
     */

    /**
     * Settings Container Key for the label of the reference container.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_REFERENCE_CONTAINER_NAME = "footnote_inputfield_references_label";

    /**
     * Settings Container Key to collapse the reference container by default.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var bool
     */
    const C_BOOL_REFERENCE_CONTAINER_COLLAPSE = "footnote_inputfield_collapse_references";

    /**
     * Settings Container Key for the positioning of the reference container.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_REFERENCE_CONTAINER_POSITION = "footnote_inputfield_reference_container_place";

    /**
     * Settings Container Key to combine identical footnotes.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var bool
     */
    const C_BOOL_COMBINE_IDENTICAL_FOOTNOTES = "footnote_inputfield_combine_identical";

    /**
     * Settings Container Key for the start of the footnotes short code.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_FOOTNOTES_SHORT_CODE_START = "footnote_inputfield_placeholder_start";

    /**
     * Settings Container Key for the end of the footnotes short code.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_FOOTNOTES_SHORT_CODE_END = "footnote_inputfield_placeholder_end";

    /**
     * Settings Container Key for the user defined start of the footnotes short code.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_FOOTNOTES_SHORT_CODE_START_USER_DEFINED = "footnote_inputfield_placeholder_start_user_defined";

    /**
     * Settings Container Key for the user defined end of the footnotes short code.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_FOOTNOTES_SHORT_CODE_END_USER_DEFINED = "footnote_inputfield_placeholder_end_user_defined";

    /**
     * Settings Container Key for the counter style of the footnotes.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_FOOTNOTES_COUNTER_STYLE = "footnote_inputfield_counter_style";

    /**
     * Settings Container Key for the 'I love footnotes' text.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_FOOTNOTES_LOVE = "footnote_inputfield_love";

    /**
     * Settings Container Key to look for footnotes in post excerpts.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_BOOL_FOOTNOTES_IN_EXCERPT = "footnote_inputfield_search_in_excerpt";

    /**
     * Settings Container Key for the Expert mode.
     *
     * @author Stefan Herndler
     * @since 1.5.5
     * @var string
     */
    const C_BOOL_FOOTNOTES_EXPERT_MODE = "footnote_inputfield_enable_expert_mode";

    /**
     * Settings Container Key for the styling before the footnotes index.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_FOOTNOTES_STYLING_BEFORE = "footnote_inputfield_custom_styling_before";

    /**
     * Settings Container Key for the styling after the footnotes index.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_FOOTNOTES_STYLING_AFTER = "footnote_inputfield_custom_styling_after";

    /**
     * Settings Container Key for the mouse-over box to be enabled.
     *
     * @author Stefan Herndler
     * @since 1.5.2
     * @var string
     */
    const C_BOOL_FOOTNOTES_MOUSE_OVER_BOX_ENABLED = "footnote_inputfield_custom_mouse_over_box_enabled";

    /**
     * Settings Container Key for alternative tooltip implementation
     *
     * @since 2.2.0
     * @var string
     *
     * 2020-11-11T1817+0100
     */
    const C_BOOL_FOOTNOTES_MOUSE_OVER_BOX_ALTERNATIVE = "footnote_inputfield_custom_mouse_over_box_alternative";

    /**
     * Settings Container Key for the mouse-over box to display only an excerpt.
     *
     * @author Stefan Herndler
     * @since 1.5.4
     * @var string
     */
    const C_BOOL_FOOTNOTES_MOUSE_OVER_BOX_EXCERPT_ENABLED = "footnote_inputfield_custom_mouse_over_box_excerpt_enabled";

    /**
     * Settings Container Key for the mouse-over box to define the max. length of the enabled excerpt.
     *
     * @author Stefan Herndler
     * @since 1.5.4
     * @var string
     */
    const C_INT_FOOTNOTES_MOUSE_OVER_BOX_EXCERPT_LENGTH = "footnote_inputfield_custom_mouse_over_box_excerpt_length";

    /**
     * Settings Container Key for the mouse-over box to define the positioning.
     *
     * @author Stefan Herndler
     * @since 1.5.7
     * @var string
     */
    const C_STR_FOOTNOTES_MOUSE_OVER_BOX_POSITION = "footnote_inputfield_custom_mouse_over_box_position";

    /**
     * Settings Container Key for the mouse-over box to define the offset (x).
     *
     * @author Stefan Herndler
     * @since 1.5.7
     * @var string
     */
    const C_INT_FOOTNOTES_MOUSE_OVER_BOX_OFFSET_X = "footnote_inputfield_custom_mouse_over_box_offset_x";

    /**
     * Settings Container Key for the mouse-over box to define the offset (y).
     *
     * @author Stefan Herndler
     * @since 1.5.7
     * @var string
     */
    const C_INT_FOOTNOTES_MOUSE_OVER_BOX_OFFSET_Y = "footnote_inputfield_custom_mouse_over_box_offset_y";

    /**
     * Settings Container Key for the mouse-over box to define the color.
     *
     * @author Stefan Herndler
     * @since 1.5.6
     * @var string
     */
    const C_STR_FOOTNOTES_MOUSE_OVER_BOX_COLOR = "footnote_inputfield_custom_mouse_over_box_color";

    /**
     * Settings Container Key for the mouse-over box to define the background color.
     *
     * @author Stefan Herndler
     * @since 1.5.6
     * @var string
     */
    const C_STR_FOOTNOTES_MOUSE_OVER_BOX_BACKGROUND = "footnote_inputfield_custom_mouse_over_box_background";

    /**
     * Settings Container Key for the mouse-over box to define the border width.
     *
     * @author Stefan Herndler
     * @since 1.5.6
     * @var string
     */
    const C_INT_FOOTNOTES_MOUSE_OVER_BOX_BORDER_WIDTH = "footnote_inputfield_custom_mouse_over_box_border_width";

    /**
     * Settings Container Key for the mouse-over box to define the border color.
     *
     * @author Stefan Herndler
     * @since 1.5.6
     * @var string
     */
    const C_STR_FOOTNOTES_MOUSE_OVER_BOX_BORDER_COLOR = "footnote_inputfield_custom_mouse_over_box_border_color";

    /**
     * Settings Container Key for the mouse-over box to define the border radius.
     *
     * @author Stefan Herndler
     * @since 1.5.6
     * @var string
     */
    const C_INT_FOOTNOTES_MOUSE_OVER_BOX_BORDER_RADIUS = "footnote_inputfield_custom_mouse_over_box_border_radius";

    /**
     * Settings Container Key for the mouse-over box to define the max width.
     *
     * @author Stefan Herndler
     * @since 1.5.6
     * @var string
     */
    const C_INT_FOOTNOTES_MOUSE_OVER_BOX_MAX_WIDTH = "footnote_inputfield_custom_mouse_over_box_max_width";

    /**
     * Settings Container Key for the mouse-over box to define the box-shadow color.
     *
     * @author Stefan Herndler
     * @since 1.5.8
     * @var string
     */
    const C_STR_FOOTNOTES_MOUSE_OVER_BOX_SHADOW_COLOR = "footnote_inputfield_custom_mouse_over_box_shadow_color";

    /**
     * Settings Container Key for the Hyperlink arrow.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_HYPERLINK_ARROW = "footnote_inputfield_custom_hyperlink_symbol";

    /**
     * Settings Container Key for the user defined Hyperlink arrow.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_HYPERLINK_ARROW_USER_DEFINED = "footnote_inputfield_custom_hyperlink_symbol_user";

    /**
     * Settings Container Key for the user defined styling.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var string
     */
    const C_STR_CUSTOM_CSS = "footnote_inputfield_custom_css";

    /**
     * Settings Container Key the activation of the_title hook.
     *
     * @author Stefan Herndler
     * @since 1.5.5
     * @var string
     */
    const C_BOOL_EXPERT_LOOKUP_THE_TITLE = "footnote_inputfield_expert_lookup_the_title";

    /**
     * Settings Container Key the activation of the_content hook.
     *
     * @author Stefan Herndler
     * @since 1.5.5
     * @var string
     */
    const C_BOOL_EXPERT_LOOKUP_THE_CONTENT = "footnote_inputfield_expert_lookup_the_content";

    /**
     * Settings Container Key the activation of the_excerpt hook.
     *
     * @author Stefan Herndler
     * @since 1.5.5
     * @var string
     */
    const C_BOOL_EXPERT_LOOKUP_THE_EXCERPT = "footnote_inputfield_expert_lookup_the_excerpt";

    /**
     * Settings Container Key the activation of widget_title hook.
     *
     * @author Stefan Herndler
     * @since 1.5.5
     * @var string
     */
    const C_BOOL_EXPERT_LOOKUP_WIDGET_TITLE = "footnote_inputfield_expert_lookup_widget_title";

    /**
     * Settings Container Key the activation of widget_text hook.
     *
     * @author Stefan Herndler
     * @since 1.5.5
     * @var string
     */
    const C_BOOL_EXPERT_LOOKUP_WIDGET_TEXT = "footnote_inputfield_expert_lookup_widget_text";

    /**
     * Settings Container Key for the label of the 'Read on' button in truncated tooltips
     *
     * @since 2.1.0
     * @var string
     *
     * 2020-11-08T2106+0100
     */
    const C_STR_FOOTNOTES_TOOLTIP_READON_LABEL = "footnote_inputfield_readon_label";

    /**
     * Settings Container Keys of options fixing default layout
     *
     * @since 2.1.1
     * @var string
     *
     * 2020-11-16T0859+0100
     */
    const C_BOOL_FOOTNOTES_REFERRER_SUPERSCRIPT_TAGS        = "footnotes_inputfield_referrer_superscript_tags";
    
    const C_BOOL_REFERENCE_CONTAINER_BACKLINK_SYMBOL_ENABLE = "footnotes_inputfield_reference_container_backlink_symbol_enable";
    const C_BOOL_REFERENCE_CONTAINER_START_PAGE_ENABLE      = "footnotes_inputfield_reference_container_start_page_enable";
    const C_BOOL_REFERENCE_CONTAINER_3COLUMN_LAYOUT_ENABLE  = "footnotes_inputfield_reference_container_3column_layout_enable";
    const C_BOOL_REFERENCE_CONTAINER_BACKLINK_SYMBOL_SWITCH = "footnotes_inputfield_reference_container_backlink_symbol_switch";

    const C_INT_EXPERT_LOOKUP_THE_TITLE_PRIORITY_LEVEL    = "footnote_inputfield_expert_lookup_the_title_priority_level";
    const C_INT_EXPERT_LOOKUP_THE_CONTENT_PRIORITY_LEVEL  = "footnote_inputfield_expert_lookup_the_content_priority_level";
    const C_INT_EXPERT_LOOKUP_THE_EXCERPT_PRIORITY_LEVEL  = "footnote_inputfield_expert_lookup_the_excerpt_priority_level";
    const C_INT_EXPERT_LOOKUP_WIDGET_TITLE_PRIORITY_LEVEL = "footnote_inputfield_expert_lookup_widget_title_priority_level";
    const C_INT_EXPERT_LOOKUP_WIDGET_TEXT_PRIORITY_LEVEL  = "footnote_inputfield_expert_lookup_widget_text_priority_level";



    /**
     * Stores a singleton reference of this class.
     *
     * @author Stefan Herndler
     * @since  1.5.0
     * @var MCI_Footnotes_Settings
     */
    private static $a_obj_Instance = null;

    /**
     * Contains all Settings Container names.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var array
     */
    private $a_arr_Container = array("footnotes_storage", "footnotes_storage_custom", "footnotes_storage_expert");

    /**
     * Contains all Default Settings for each Settings Container.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var array
     */
    private $a_arr_Default = array(

        "footnotes_storage" => array(

            self::C_STR_REFERENCE_CONTAINER_NAME => 'References',
            self::C_BOOL_REFERENCE_CONTAINER_COLLAPSE => '',
            self::C_STR_REFERENCE_CONTAINER_POSITION => 'post_end',
            // Identical footnotes should not be combined by default
            // as long as the feature raises criticism for malfunctioning:
            // <https://wordpress.org/support/topic/too-many-errors-18/>
            self::C_BOOL_COMBINE_IDENTICAL_FOOTNOTES => '',

            self::C_BOOL_REFERENCE_CONTAINER_BACKLINK_SYMBOL_ENABLE => 'yes',
            self::C_BOOL_REFERENCE_CONTAINER_START_PAGE_ENABLE      => 'yes',
            self::C_BOOL_REFERENCE_CONTAINER_3COLUMN_LAYOUT_ENABLE  => '',
            self::C_BOOL_REFERENCE_CONTAINER_BACKLINK_SYMBOL_SWITCH => '',

            self::C_STR_FOOTNOTES_SHORT_CODE_START => '((',
            self::C_STR_FOOTNOTES_SHORT_CODE_END => '))',
            self::C_STR_FOOTNOTES_SHORT_CODE_START_USER_DEFINED => '',
            self::C_STR_FOOTNOTES_SHORT_CODE_END_USER_DEFINED => '',
            self::C_STR_FOOTNOTES_COUNTER_STYLE => 'arabic_plain',
            self::C_STR_FOOTNOTES_LOVE => 'no',
            self::C_BOOL_FOOTNOTES_IN_EXCERPT => 'yes',
            self::C_BOOL_FOOTNOTES_EXPERT_MODE => 'no'

        ),

        "footnotes_storage_custom" => array(

            self::C_STR_FOOTNOTES_TOOLTIP_READON_LABEL => 'Continue reading',

            self::C_BOOL_FOOTNOTES_REFERRER_SUPERSCRIPT_TAGS => 'yes',

            // The default footnote referrer surroundings should be square brackets:
            // * as in English typesetting;
            // * for better UX thanks to a more button-like appearance;
            // * for stylistic consistency with the expand-collapse button
            self::C_STR_FOOTNOTES_STYLING_BEFORE => '[',
            self::C_STR_FOOTNOTES_STYLING_AFTER => ']',

            self::C_BOOL_FOOTNOTES_MOUSE_OVER_BOX_ENABLED => 'yes',
            self::C_BOOL_FOOTNOTES_MOUSE_OVER_BOX_ALTERNATIVE => '',

            // The mouse over content truncation should be enabled by default
            // to raise awareness of the functionality and to prevent the screen
            // from being filled at mouse-over, and to allow the Continue reading:
            self::C_BOOL_FOOTNOTES_MOUSE_OVER_BOX_EXCERPT_ENABLED => 'yes',

            // The truncation length is raised from 150 to 200 chars:
            self::C_INT_FOOTNOTES_MOUSE_OVER_BOX_EXCERPT_LENGTH => 200,

            // The default position should not be lateral because of the risk
            // the box gets squeezed between note anchor at line end and window edge,
            // and top because reading at the bottom of the window is more likely:
            self::C_STR_FOOTNOTES_MOUSE_OVER_BOX_POSITION => 'top center',

            self::C_INT_FOOTNOTES_MOUSE_OVER_BOX_OFFSET_X => 0,
            // The vertical offset must be negative for the box not to cover
            // the current line of text (web coordinates origin is top left):
            self::C_INT_FOOTNOTES_MOUSE_OVER_BOX_OFFSET_Y => -7,

            self::C_STR_FOOTNOTES_MOUSE_OVER_BOX_COLOR => '',
            // The mouse over box shouldn’t feature a colored background
            // by default, due to diverging user preferences. White is neutral:
            self::C_STR_FOOTNOTES_MOUSE_OVER_BOX_BACKGROUND => '#ffffff',

            self::C_INT_FOOTNOTES_MOUSE_OVER_BOX_BORDER_WIDTH => 1,
            self::C_STR_FOOTNOTES_MOUSE_OVER_BOX_BORDER_COLOR => '#cccc99',

            // The mouse over box corners mustn’t be rounded as that is outdated:
            self::C_INT_FOOTNOTES_MOUSE_OVER_BOX_BORDER_RADIUS => 0,

            // The width should be limited to start with, for the box to have shape:
            self::C_INT_FOOTNOTES_MOUSE_OVER_BOX_MAX_WIDTH => 450,

            self::C_STR_FOOTNOTES_MOUSE_OVER_BOX_SHADOW_COLOR => '#666666',
            self::C_STR_HYPERLINK_ARROW => '&#8593;',
            self::C_STR_HYPERLINK_ARROW_USER_DEFINED => '',
            self::C_STR_CUSTOM_CSS => ''

        ),

        "footnotes_storage_expert" => array(

            // Titles should all be enabled by default to prevent users from
            // thinking at first that the feature is broken in post titles.
            // See <https://wordpress.org/support/topic/more-feature-ideas/>
            // Yet in titles, footnotes are functionally pointless in WordPress.
            self::C_BOOL_EXPERT_LOOKUP_THE_TITLE => '',
            self::C_BOOL_EXPERT_LOOKUP_THE_CONTENT => 'yes',
            self::C_BOOL_EXPERT_LOOKUP_THE_EXCERPT => 'yes',
            self::C_BOOL_EXPERT_LOOKUP_WIDGET_TITLE => '',
            self::C_BOOL_EXPERT_LOOKUP_WIDGET_TEXT => 'yes',

            // initially hard-coded default
            // shows "9223372036854775807" in the numbox
            // empty should be interpreted as PHP_INT_MAX, 
            // but a numbox cannot be set to empty: <https://github.com/Modernizr/Modernizr/issues/171>
            // define -1 as PHP_INT_MAX instead
            self::C_INT_EXPERT_LOOKUP_THE_TITLE_PRIORITY_LEVEL    => PHP_INT_MAX,
            self::C_INT_EXPERT_LOOKUP_THE_CONTENT_PRIORITY_LEVEL  => PHP_INT_MAX,
            self::C_INT_EXPERT_LOOKUP_THE_EXCERPT_PRIORITY_LEVEL  => PHP_INT_MAX,
            self::C_INT_EXPERT_LOOKUP_WIDGET_TITLE_PRIORITY_LEVEL => PHP_INT_MAX,
            self::C_INT_EXPERT_LOOKUP_WIDGET_TEXT_PRIORITY_LEVEL  => PHP_INT_MAX,

        )

    );

    /**
     * Contains all Settings from each Settings container as soon as this class is initialized.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @var array
     */
    private $a_arr_Settings = array();

    /**
     * Class Constructor. Loads all Settings from each WordPress Settings container.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     */
    private function __construct() {
        $this->loadAll();
    }

    /**
     * Returns a singleton of this class.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @return MCI_Footnotes_Settings
     */
    public static function instance() {
        // no instance defined yet, load it
        if (self::$a_obj_Instance === null) {
            self::$a_obj_Instance = new self();
        }
        // return a singleton of this class
        return self::$a_obj_Instance;
    }

    /**
     * Returns the name of a specified Settings Container.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @param int $p_int_Index Settings Container Array Key Index.
     * @return string Settings Container name.
     */
    public function getContainer($p_int_Index) {
        return $this->a_arr_Container[$p_int_Index];
    }

    /**
     * Returns the default values of a specific Settings Container.
     *
     * @author Stefan Herndler
     * @since 1.5.6
     * @param int $p_int_Index Settings Container Aray Key Index.
     * @return array
     */
    public function getDefaults($p_int_Index) {
        return $this->a_arr_Default[$this->a_arr_Container[$p_int_Index]];
    }

    /**
     * Loads all Settings from each Settings container.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     */
    private function loadAll() {
        // clear current settings
        $this->a_arr_Settings = array();
        for ($i = 0; $i < count($this->a_arr_Container); $i++) {
            // load settings
            $this->a_arr_Settings = array_merge($this->a_arr_Settings, $this->Load($i));
        }
    }

    /**
     * Loads all Settings from specified Settings Container.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @param int $p_int_Index Settings Container Array Key Index.
     * @return array Settings loaded from Container of Default Settings if Settings Container is empty (first usage).
     */
    private function Load($p_int_Index) {
        // load all settings from container
        $l_arr_Options = get_option($this->getContainer($p_int_Index));
        // load all default settings
        $l_arr_Default = $this->a_arr_Default[$this->getContainer($p_int_Index)];

        // no settings found, set them to their default value
        if (empty($l_arr_Options)) {
            return $l_arr_Default;
        }
        // iterate through all available settings ( = default values)
        foreach($l_arr_Default as $l_str_Key => $l_str_Value) {
            // available setting not found in the container
            if (!array_key_exists($l_str_Key, $l_arr_Options)) {
                // define the setting with its default value
                $l_arr_Options[$l_str_Key] = $l_str_Value;
            }
        }
        // iterate through each setting in the container
        foreach($l_arr_Options as $l_str_Key => $l_str_Value) {
            // remove all whitespace at the beginning and end of a setting
            //$l_str_Value = trim($l_str_Value);
            // write the sanitized value back to the setting container
            $l_arr_Options[$l_str_Key] = $l_str_Value;
        }
        // return settings loaded from Container
        return $l_arr_Options;
    }

    /**
     * Updates a whole Settings container.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @param int $p_int_Index Index of the Settings container.
     * @param array $p_arr_newValues new Settings.
     * @return bool
     */
    public function saveOptions($p_int_Index, $p_arr_newValues) {
        if (update_option($this->getContainer($p_int_Index), $p_arr_newValues)) {
            $this->loadAll();
            return true;
        }
        return false;
    }

    /**
     * Returns the value of specified Settings name.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     * @param string $p_str_Key Settings Array Key name.
     * @return mixed Value of the Setting on Success or Null in Settings name is invalid.
     */
    public function get($p_str_Key) {
        return array_key_exists($p_str_Key, $this->a_arr_Settings) ? $this->a_arr_Settings[$p_str_Key] : null;
    }

    /**
     * Deletes each Settings Container and loads the default values for each Settings Container.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     */
    public function ClearAll() {
        // iterate through each Settings Container
        for ($i = 0; $i < count($this->a_arr_Container); $i++) {
            // delete the settings container
            delete_option($this->getContainer($i));
        }
        // set settings back to the default values
        $this->a_arr_Settings = $this->a_arr_Default;
    }

    /**
     * Register all Settings Container for the Plugin Settings Page in the Dashboard.
     * Settings Container Label will be the same as the Settings Container Name.
     *
     * @author Stefan Herndler
     * @since 1.5.0
     */
    public function RegisterSettings() {
        // register all settings
        for ($i = 0; $i < count($this->a_arr_Container); $i++) {
            register_setting($this->getContainer($i), $this->getContainer($i));
        }
    }
}