footnotes/classes/footnotes_settings.php

<?php
/**
 * Created by Stefan Herndler.
 * User: Stefan
 * Date: 15.05.14
 * Time: 16:21
 * Version: 1.0.7
 * Since: 1.0
 */

/**
 * Class Class_FootnotesSettings
 * @since 1.0
 */
class Class_FootnotesSettings
{
    /*
     * attribute for default settings value
     * updated default value for 'FOOTNOTE_INPUTFIELD_LOVE' to default: 'no' in version 1.0.6
     * @since 1.0
     */
    public static $a_arr_Default_Settings = array(
        FOOTNOTE_INPUTFIELD_COMBINE_IDENTICAL => 'yes',
        FOOTNOTE_INPUTFIELD_REFERENCES_LABEL => 'References',
        FOOTNOTE_INPUTFIELD_COLLAPSE_REFERENCES => '',
        FOOTNOTE_INPUTFIELD_PLACEHOLDER_START => '((',
        FOOTNOTE_INPUTFIELD_PLACEHOLDER_END => '))',
        FOOTNOTE_INPUTFIELD_SEARCH_IN_EXCERPT => 'yes',
        FOOTNOTE_INPUTFIELD_LOVE => 'no',
        FOOTNOTE_INPUTFIELD_COUNTER_STYLE => 'arabic_plain',
        FOOTNOTE_INPUTFIELD_REFERENCE_CONTAINER_PLACE => 'post_end',
        FOOTNOTE_INPUTFIELD_PLACEHOLDER_START_USERDEFINED => '',
        FOOTNOTE_INPUTFIELD_PLACEHOLDER_END_USERDEFINED => ''
    );
    /*
     * resulting pagehook for adding a new sub menu page to the settings
     * @since 1.0
     */
    var $a_str_Pagehook;
    /*
     * collection of settings values for this plugin
     * @since 1.0
     */
    var $a_arr_Options;
    /*
     * collection of tabs for the settings page of this plugin
     * @since 1.0
     */
    private $a_arr_SettingsTabs = array();

    /**
     * @constructor
     * @since 1.0
     */
    function __construct()
    {
        /* loads and filters the settings for this plugin */
        $this->a_arr_Options = footnotes_filter_options(FOOTNOTE_SETTINGS_CONTAINER, self::$a_arr_Default_Settings, true);

        /* execute class includes on action-even: init, admin_init and admin_menu */
        add_action('init', array($this, 'LoadScriptsAndStylesheets'));
        add_action('admin_init', array($this, 'RegisterSettings'));

        add_action('admin_init', array($this, 'RegisterTab_General'));
        add_action('admin_init', array($this, 'RegisterTab_HowTo'));

        add_action('admin_menu', array($this, 'AddSettingsMenuPanel'));
    }

    /**
     * initialize settings page, loads scripts and stylesheets needed for the layout
     * called in class constructor @ init
     * @since 1.0
     */
    function LoadScriptsAndStylesheets()
    {
        /* add the jQuery plugin (already registered by WP) */
        wp_enqueue_script('jquery');
        /* register public stylesheet */
        wp_register_style('footnote_public_style', plugins_url('../css/footnote.css', __FILE__));
        /* add public stylesheet */
        wp_enqueue_style('footnote_public_style');
        /* register settings stylesheet */
        wp_register_style('footnote_settings_style', plugins_url('../css/settings.css', __FILE__));
        /* add settings stylesheet */
        wp_enqueue_style('footnote_settings_style');
        /* Needed to allow metabox layout and close functionality */
        wp_enqueue_script('postbox');
    }

    /**
     * register the settings field in the database for the "save" function
     * called in class constructor @ admin_init
     * @since 1.0
     */
    function RegisterSettings()
    {
        register_setting(FOOTNOTE_SETTINGS_LABEL_GENERAL, FOOTNOTE_SETTINGS_CONTAINER);
    }

    /**
     * sets the plugin's title for the admins settings menu
     * called in class constructor @ admin_menu
     * @since 1.0
     */
    function AddSettingsMenuPanel()
    {
        /* current user needs the permission to update plugins for further access */
        if (!current_user_can('update_plugins')) {
            return;
        }
        /* submenu page title */
        $l_str_PageTitle = FOOTNOTES_PLUGIN_PUBLIC_NAME;
        /* submenu title */
        $l_str_MenuTitle = FOOTNOTES_PLUGIN_PUBLIC_NAME;
        /* Add a new submenu to the standard Settings panel */
        $this->a_str_Pagehook = add_options_page($l_str_PageTitle, $l_str_MenuTitle, 'administrator', FOOTNOTES_SETTINGS_PAGE_ID, array($this, 'OutputSettingsPage'));
    }

    /**
     * Plugin Options page rendering goes here, checks
     * for active tab and replaces key with the related
     * settings key. Uses the plugin_options_tabs method
     * to render the tabs.
     * @since 1.0
     */
    function OutputSettingsPage()
    {
        /* gets active tag, or if nothing set the "general" tab will be set to active */
        $l_str_tab = isset($_GET['tab']) ? $_GET['tab'] : FOOTNOTE_SETTINGS_LABEL_GENERAL;
        /* outputs all tabs */
        echo '<div class="wrap">';
        $this->OutputSettingsPageTabs();
        /* outputs a form with the content of the current active tab */
        echo '<form method="post" action="options.php">';
        wp_nonce_field('update-options');
        settings_fields($l_str_tab);
        /* outputs the settings field of the current active tab */
        do_settings_sections($l_str_tab);
        do_meta_boxes($l_str_tab, 'main');
        /* adds a submit button to the current page */
        /*
         * add submit button only if there are some settings on the current page
         * @since version 1.0.7
         */
        if ($l_str_tab == FOOTNOTE_SETTINGS_LABEL_GENERAL) {
            submit_button();
        }
        echo '</form>';
        echo '</div>';
        /*
         * output settings page specific javascript code
         * @since 1.0.7
         */
        $this->OutputJavascript();
    }

    /**
     * Renders our tabs in the plugin options page,
     * walks through the object's tabs array and prints
     * them one by one. Provides the heading for the
     * plugin_options_page method.
     * @since 1.0
     */
    function OutputSettingsPageTabs()
    {
        /* gets active tag, or if nothing set the "general" tab will be set to active */
        $l_str_CurrentTab = isset($_GET['tab']) ? $_GET['tab'] : FOOTNOTE_SETTINGS_LABEL_GENERAL;
        screen_icon();
        echo '<h2 class="nav-tab-wrapper">';
        foreach ($this->a_arr_SettingsTabs as $l_str_TabKey => $l_str_TabCaption) {
            $active = $l_str_CurrentTab == $l_str_TabKey ? 'nav-tab-active' : '';
            echo '<a class="nav-tab ' . $active . '" href="?page=' . FOOTNOTES_SETTINGS_PAGE_ID . '&tab=' . $l_str_TabKey . '">' . $l_str_TabCaption . '</a>';
        }
        echo '</h2>';
    }

    /**
     * outputs page specific javascript code
     * @since 1.0.7
     */
    function OutputJavascript()
    {
        ?>
        <!-- Needed to allow metabox layout and close functionality. -->
        <script type="text/javascript">
            jQuery(document).ready(function ($) {
                // close postboxes that should be closed
                $('.if-js-closed').removeClass('if-js-closed').addClass('closed');
                // postboxes setup
                postboxes.add_postbox_toggles('<?php echo $this->a_str_Pagehook; ?>');

                jQuery('#<?php echo $this->getFieldID(FOOTNOTE_INPUTFIELD_PLACEHOLDER_START); ?>').on('change', function() {
                    var l_int_SelectedIndex = jQuery(this).prop("selectedIndex");
                    jQuery('#<?php echo $this->getFieldID(FOOTNOTE_INPUTFIELD_PLACEHOLDER_END); ?> option:eq(' + l_int_SelectedIndex + ')').prop('selected', true);
                    footnotes_Display_UserDefined_Placeholders();
                });
                jQuery('#<?php echo $this->getFieldID(FOOTNOTE_INPUTFIELD_PLACEHOLDER_END); ?>').on('change', function() {
                    var l_int_SelectedIndex = jQuery(this).prop("selectedIndex");
                    jQuery('#<?php echo $this->getFieldID(FOOTNOTE_INPUTFIELD_PLACEHOLDER_START); ?> option:eq(' + l_int_SelectedIndex + ')').prop('selected', true);
                    footnotes_Display_UserDefined_Placeholders();
                });
                footnotes_Display_UserDefined_Placeholders();
            });

            function footnotes_Display_UserDefined_Placeholders() {
                if (jQuery('#<?php echo $this->getFieldID(FOOTNOTE_INPUTFIELD_PLACEHOLDER_START); ?>').val() == "userdefined") {
                    jQuery('#<?php echo $this->getFieldID(FOOTNOTE_INPUTFIELD_PLACEHOLDER_START_USERDEFINED); ?>').show();
                    jQuery('#<?php echo $this->getFieldID(FOOTNOTE_INPUTFIELD_PLACEHOLDER_END_USERDEFINED); ?>').show();
                } else {
                    jQuery('#<?php echo $this->getFieldID(FOOTNOTE_INPUTFIELD_PLACEHOLDER_START_USERDEFINED); ?>').hide();
                    jQuery('#<?php echo $this->getFieldID(FOOTNOTE_INPUTFIELD_PLACEHOLDER_END_USERDEFINED); ?>').hide();
                }
            }
        </script>
    <?php
    }

    /**
     * loads specific setting and returns an array with the keys [id, name, value]
     * @since 1.0
     * @param $p_str_FieldID
     * @return array
     */
    protected function LoadSetting($p_str_FieldID)
    {
        $p_arr_Return = array();
        $p_arr_Return["id"] = $this->getFieldID($p_str_FieldID);
        $p_arr_Return["name"] = $this->getFieldName($p_str_FieldID);
        $p_arr_Return["value"] = esc_attr($this->getFieldValue($p_str_FieldID));
        return $p_arr_Return;
    }

    /**
     * access settings field by name
     * @since 1.0
     * @param string $p_str_FieldName
     * @return string
     */
    protected function getFieldName($p_str_FieldName)
    {
        return sprintf('%s[%s]', FOOTNOTE_SETTINGS_CONTAINER, $p_str_FieldName);
        //return sprintf( '%s', $p_str_FieldName );
    }

    /**
     * access settings field by id
     * @since 1.0
     * @param string $p_str_FieldID
     * @return string
     */
    protected function getFieldID($p_str_FieldID)
    {
        //return sprintf('%s[%s]', FOOTNOTE_SETTINGS_CONTAINER, $p_str_FieldID);
        return sprintf( '%s', $p_str_FieldID );
    }

    /**
     * get settings field value
     * @since 1.0
     * @param string $p_str_Key
     * @return string
     */
    protected function getFieldValue($p_str_Key)
    {
        return $this->a_arr_Options[$p_str_Key];
    }

    /**
     * outputs a break to have a new line
     * @since 1.0.7
     */
    function AddNewline()
    {
        echo '<br/><br/>';
    }

	/**
	 * outputs a simple text
	 * @param string $p_str_Text
	 * @since 1.1.1
	 */
	function AddText($p_str_Text)
	{
		echo '<span>' . $p_str_Text . '</span>';
	}

    /**
     * outputs a label for a specific input/select box
     * @param string $p_str_SettingsID
     * @param string $p_str_Caption
     * @param string $p_str_Styling
     * @since 1.0.7
     */
    function AddLabel($p_str_SettingsID, $p_str_Caption, $p_str_Styling = "")
    {
        /* add styling tag if styling is set */
        if (!empty($p_str_Styling)) {
            $p_str_Styling = ' style="' . $p_str_Styling . '"';
        }
        echo '<label for="' . $p_str_SettingsID . '"' . $p_str_Styling . '>' . $p_str_Caption . '</label>';
    }

    /**
     * outputs a input type=text
     * @param string $p_str_SettingsID [id of the settings field]
     * @param string $p_str_ClassName [css class name]
     * @param int $p_str_MaxLength [max length for the input value]
	 * @param bool $p_bool_Readonly [input is readonly] in version 1.1.1
     * @param bool $p_bool_Hidden [input is hidden by default] in version 1.1.2
     * @since 1.0-beta
     * removed optional paremter for a label in version 1.0.7
     */
    function AddTextbox($p_str_SettingsID, $p_str_ClassName = "", $p_str_MaxLength = 0, $p_bool_Readonly = false, $p_bool_Hidden = false)
    {
        /* collect data for given settings field */
        $l_arr_Data = $this->LoadSetting($p_str_SettingsID);

        /* if input shall have a css class, add the style tag for it */
        if (!empty($p_str_ClassName)) {
            $p_str_ClassName = 'class="' . $p_str_ClassName . '"';
        }
        /* optional add a maxlength to the input field */
        if (!empty($p_str_MaxLength)) {
            $p_str_MaxLength = ' maxlength="' . $p_str_MaxLength . '"';
        }

		if ($p_bool_Readonly) {
			$p_bool_Readonly = ' readonly="readonly"';
		}
        if ($p_bool_Hidden) {
            $p_bool_Hidden = ' style="display:none;"';
        }
        /* outputs an input field type TEXT */
        echo '<input type="text" ' . $p_str_ClassName . $p_str_MaxLength . $p_bool_Readonly . $p_bool_Hidden . ' name="' . $l_arr_Data["name"] . '" id="' . $l_arr_Data["id"] . '" value="' . $l_arr_Data["value"] . '"/>';
    }

    /**
     * outputs a input type=checkbox
     * @param string $p_str_SettingsID [id of the settings field]
     * @param string $p_str_ClassName [optional css class name]
     * @since 1.0-beta
     */
    function AddCheckbox($p_str_SettingsID, $p_str_ClassName = "")
    {
        /* collect data for given settings field */
        $l_arr_Data = $this->LoadSetting($p_str_SettingsID);

        /* if input shall have a css class, add the style tag for it */
        if (!empty($p_str_ClassName)) {
            $p_str_ClassName = 'class="' . $p_str_ClassName . '"';
        }

        /* lookup if the checkbox shall be pre-checked */
        $l_str_Checked = "";
        if (footnotes_ConvertToBool($l_arr_Data["value"])) {
            $l_str_Checked = 'checked="checked"';
        }

        /* outputs an input field type CHECKBOX */
        echo sprintf('<input type="checkbox" ' . $p_str_ClassName . ' name="' . $l_arr_Data["name"] . '" id="' . $l_arr_Data["id"] . '" %s/>', $l_str_Checked);
    }

    /**
     * outputs a select box
     * @param string $p_str_SettingsID [id of the settings field]
     * @param array $p_arr_Options [array with options]
     * @param string $p_str_ClassName [optional css class name]
     * @since 1.0-beta
     */
    function AddSelectbox($p_str_SettingsID, $p_arr_Options, $p_str_ClassName = "")
    {
        /* collect data for given settings field */
        $l_arr_Data = $this->LoadSetting($p_str_SettingsID);

        /* if input shall have a css class, add the style tag for it */
        if (!empty($p_str_ClassName)) {
            $p_str_ClassName = 'class="' . $p_str_ClassName . '"';
        }

        /* select starting tag */
        $l_str_Output = '<select ' . $p_str_ClassName . ' name="' . $l_arr_Data["name"] . '" id="' . $l_arr_Data["id"] . '">';
        /* loop through all array keys */
        foreach ($p_arr_Options as $l_str_Value => $l_str_Caption) {
            /* add key as option value */
            $l_str_Output .= '<option value="' . $l_str_Value . '"';
            /* check if option value is set and has to be pre-selected */
            if ($l_arr_Data["value"] == $l_str_Value) {
                $l_str_Output .= ' selected';
            }
            /* write option caption and close option tag */
            $l_str_Output .= '>' . $l_str_Caption . '</option>';
        }
        /* close select */
        $l_str_Output .= '</select>';
        /* outputs the SELECT field */
        echo $l_str_Output;
    }

    /**
     * initialize general settings tab
     * called in class constructor @ admin_init
     * @since 1.0
     * changed layout of settings form settings fields to meta boxes in version 1.0.7
     */
    function RegisterTab_General()
    {
        /* add tab to the tab array */
        $this->a_arr_SettingsTabs[FOOTNOTE_SETTINGS_LABEL_GENERAL] = __("General", FOOTNOTES_PLUGIN_NAME);
        /* register settings tab */
        add_settings_section("Footnote_Secion_Settings_General", sprintf(__("%s Settings", FOOTNOTES_PLUGIN_NAME), FOOTNOTES_PLUGIN_PUBLIC_NAME), array($this, 'RegisterTab_General_Description'), FOOTNOTE_SETTINGS_LABEL_GENERAL);
        add_meta_box('Register_MetaBox_ReferenceContainer', __("References Container", FOOTNOTES_PLUGIN_NAME), array($this, 'Register_MetaBox_ReferenceContainer'), FOOTNOTE_SETTINGS_LABEL_GENERAL, 'main');
        add_meta_box('Register_MetaBox_FootnoteStyling', sprintf(__("%s styling", FOOTNOTES_PLUGIN_NAME), FOOTNOTES_PLUGIN_PUBLIC_NAME), array($this, 'Register_MetaBox_FootnoteStyling'), FOOTNOTE_SETTINGS_LABEL_GENERAL, 'main');
		add_meta_box('Register_MetaBox_Love', FOOTNOTES_PLUGIN_PUBLIC_NAME . '&nbsp;<span style="color:#ff6d3b; font-weight:bold;">&hearts;</span>', array($this, 'Register_MetaBox_Love'), FOOTNOTE_SETTINGS_LABEL_GENERAL, 'main');
		add_meta_box('Register_MetaBox_Other', __("Other", FOOTNOTES_PLUGIN_NAME), array($this, 'Register_MetaBox_Other'), FOOTNOTE_SETTINGS_LABEL_GENERAL, 'main');
    }

    /**
     * adds a desciption to the general settings tab
     * called in RegisterTab_General
     * @since 1.0
     */
    function RegisterTab_General_Description()
    {
        // unused description
    }

    /**
     * outputs a container for the reference container settings
     * @since 1.0.7
     */
    function Register_MetaBox_ReferenceContainer()
    {
        /* setting for 'reference label' */
        $this->AddLabel(FOOTNOTE_INPUTFIELD_REFERENCES_LABEL, __("References label:", FOOTNOTES_PLUGIN_NAME));
        $this->AddTextbox(FOOTNOTE_INPUTFIELD_REFERENCES_LABEL, "footnote_plugin_50");
        $this->AddNewline();

        /* setting for 'collapse reference container by default' */
        $this->AddLabel(FOOTNOTE_INPUTFIELD_COLLAPSE_REFERENCES, __("Collapse references by default:", FOOTNOTES_PLUGIN_NAME));
        $this->AddCheckbox(FOOTNOTE_INPUTFIELD_COLLAPSE_REFERENCES);
        $this->AddNewline();

        /*
         * setting for 'placement of the reference container'
         * @since 1.0.7
         */
        $l_arr_Options = array(
            "footer" => __("in the footer", FOOTNOTES_PLUGIN_NAME),
            "post_end" => __("at the end of the post", FOOTNOTES_PLUGIN_NAME),
			"widget" => __("in the widget area", FOOTNOTES_PLUGIN_NAME)
        );
        $this->AddLabel(FOOTNOTE_INPUTFIELD_REFERENCE_CONTAINER_PLACE, __("Where shall the reference container appear:", FOOTNOTES_PLUGIN_NAME));
        $this->AddSelectbox(FOOTNOTE_INPUTFIELD_REFERENCE_CONTAINER_PLACE, $l_arr_Options, "footnote_plugin_50");
    }

    /**
     * outputs a container for the styling of footnotes
     * @since 1.0.7
     */
    function Register_MetaBox_FootnoteStyling()
    {
        /* setting for 'combine identical footnotes' */
        $l_arr_Options = array(
            "yes" => __("Yes", FOOTNOTES_PLUGIN_NAME),
            "no" => __("No", FOOTNOTES_PLUGIN_NAME)
        );
        $this->AddLabel(FOOTNOTE_INPUTFIELD_COMBINE_IDENTICAL, __("Combine identical footnotes:", FOOTNOTES_PLUGIN_NAME));
        $this->AddSelectbox(FOOTNOTE_INPUTFIELD_COMBINE_IDENTICAL, $l_arr_Options, "footnote_plugin_50");
        $this->AddNewline();


        /* setting for 'footnote tag starts with' */
        $l_arr_Options = array(
            "((" => "((",
            "<fn>" => htmlspecialchars("<fn>"),
            "[ref]" => "[ref]",
            "userdefined" => __('user defined', FOOTNOTES_PLUGIN_NAME)
        );
        $this->AddLabel(FOOTNOTE_INPUTFIELD_PLACEHOLDER_START, __("Footnote tag starts with:", FOOTNOTES_PLUGIN_NAME));
        $this->AddSelectbox(FOOTNOTE_INPUTFIELD_PLACEHOLDER_START, $l_arr_Options, "footnote_plugin_15");

        /* setting for 'footnote tag ends with' */
        $l_arr_Options = array(
            "))" => "))",
            "</fn>" => htmlspecialchars("</fn>"),
            "[/ref]" => "[/ref]",
            "userdefined" => __('user defined', FOOTNOTES_PLUGIN_NAME)
        );
        $this->AddLabel(FOOTNOTE_INPUTFIELD_PLACEHOLDER_END, __("and ends with:", FOOTNOTES_PLUGIN_NAME) . '&nbsp;&nbsp;&nbsp;', 'text-align: right;');
        $this->AddSelectbox(FOOTNOTE_INPUTFIELD_PLACEHOLDER_END, $l_arr_Options, "footnote_plugin_15");
        $this->AddNewline();

        /* user defined setting for 'footnote start and end tag' */
        $this->AddLabel(FOOTNOTE_INPUTFIELD_PLACEHOLDER_START_USERDEFINED, "");
        $this->AddTextbox(FOOTNOTE_INPUTFIELD_PLACEHOLDER_START_USERDEFINED, "footnote_plugin_15", 14, false, true);
        $this->AddLabel(FOOTNOTE_INPUTFIELD_PLACEHOLDER_END_USERDEFINED, "");
        $this->AddTextbox(FOOTNOTE_INPUTFIELD_PLACEHOLDER_END_USERDEFINED, "footnote_plugin_15", 14, false, true);
        $this->AddNewline();

        /* setting for 'footnotes counter style' */
        $l_str_Space = "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;";
        $l_arr_Options = array(
            "arabic_plain" => __("Arabic Numbers - Plain", FOOTNOTES_PLUGIN_NAME) . $l_str_Space . "1, 2, 3, 4, 5, ...",
            "arabic_leading" => __("Arabic Numbers - Leading 0", FOOTNOTES_PLUGIN_NAME) . $l_str_Space . "01, 02, 03, 04, 05, ...",
            "latin_low" => __("Latin Character - lower case", FOOTNOTES_PLUGIN_NAME) . $l_str_Space . "a, b, c, d, e, ...",
            "latin_high" => __("Latin Character - upper case", FOOTNOTES_PLUGIN_NAME) . $l_str_Space . "A, B, C, D, E, ...",
            "romanic" => __("Roman Numerals", FOOTNOTES_PLUGIN_NAME) . $l_str_Space . "I, II, III, IV, V, ..."
        );
        $this->AddLabel(FOOTNOTE_INPUTFIELD_COUNTER_STYLE, __('Counter style:', FOOTNOTES_PLUGIN_NAME));
        $this->AddSelectbox(FOOTNOTE_INPUTFIELD_COUNTER_STYLE, $l_arr_Options, "footnote_plugin_50");
    }

	/**
	 * outputs other footnotes settings that doesn't match a special category
	 * @since 1.0.7
	 */
	function Register_MetaBox_Love()
	{
		/* setting for 'love and share this plugin in my footer' */
		$l_arr_Options = array(
			"yes" => __("Yes", FOOTNOTES_PLUGIN_NAME),
			"no" => __("No", FOOTNOTES_PLUGIN_NAME)
		);
		$this->AddLabel(FOOTNOTE_INPUTFIELD_LOVE, sprintf(__("Tell the world you're using %s:", FOOTNOTES_PLUGIN_NAME), FOOTNOTES_PLUGIN_PUBLIC_NAME));
		$this->AddSelectbox(FOOTNOTE_INPUTFIELD_LOVE, $l_arr_Options, "footnote_plugin_50");
		$this->AddNewline();

		/* no 'love me' on specific pages */
		$this->AddText(sprintf(__("Don't tell the world you're using %s on specific pages by adding the following short code:", FOOTNOTES_PLUGIN_NAME), FOOTNOTES_PLUGIN_PUBLIC_NAME));
		$this->AddText("&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;");
		$this->AddText(FOOTNOTES_NO_SLUGME_PLUG);
	}

    /**
     * outputs other footnotes settings that doesn't match a special category
     * @since 1.0.7
     */
    function Register_MetaBox_Other()
    {
        /* setting for 'search footnotes tag in excerpt' */
        $l_arr_Options = array(
            "yes" => __("Yes", FOOTNOTES_PLUGIN_NAME),
            "no" => __("No", FOOTNOTES_PLUGIN_NAME)
        );
        $this->AddLabel(FOOTNOTE_INPUTFIELD_SEARCH_IN_EXCERPT, __('Allow footnotes on Summarized Posts:', FOOTNOTES_PLUGIN_NAME));
        $this->AddSelectbox(FOOTNOTE_INPUTFIELD_SEARCH_IN_EXCERPT, $l_arr_Options, "footnote_plugin_50");
    }

    /**
     * initialize howto settings tab
     * called in class constructor @ admin_init
     * @since 1.0
     * changed layout of settings form settings fields to meta boxes in version 1.0.7
     */
    function RegisterTab_HowTo()
    {
        /* add tab to the tab array */
        $this->a_arr_SettingsTabs[FOOTNOTE_SETTINGS_LABEL_HOWTO] = __("HowTo", FOOTNOTES_PLUGIN_NAME);
        /* register settings tab */
        add_settings_section("Footnote_Secion_Settings_Howto", "&nbsp;", array($this, 'RegisterTab_HowTo_Description'), FOOTNOTE_SETTINGS_LABEL_HOWTO);
        add_meta_box('Register_MetaBox_HowTo', __("Brief introduction in how to use the plugin", FOOTNOTES_PLUGIN_NAME), array($this, 'Register_MetaBox_HowTo'), FOOTNOTE_SETTINGS_LABEL_HOWTO, 'main');
    }

    /**
     * adds a descrption to the HowTo settings tab
     * called int RegisterTab_HowTo
     * @since 1.0
     * removed output of description in version 1.0.7
     */
    function RegisterTab_HowTo_Description()
    {
        // unused
    }

    /**
     * outputs the content of the HowTo settings tab
     * @since 1.0
     */
    function Register_MetaBox_HowTo()
    {
        $l_arr_Footnote_StartingTag = $this->LoadSetting(FOOTNOTE_INPUTFIELD_PLACEHOLDER_START);
        $l_arr_Footnote_EndingTag = $this->LoadSetting(FOOTNOTE_INPUTFIELD_PLACEHOLDER_END);
        ?>
        <div style="text-align:center;">
            <div class="footnote_placeholder_box_container">
                <p>
                    <?php echo __("Start your footnote with the following shortcode:", FOOTNOTES_PLUGIN_NAME); ?>
                    <span
                        class="footnote_highlight_placeholder"><?php echo $l_arr_Footnote_StartingTag["value"]; ?></span>
                </p>

                <p>
                    <?php echo __("...and end your footnote with this shortcode:", FOOTNOTES_PLUGIN_NAME); ?>
                    <span
                        class="footnote_highlight_placeholder"><?php echo $l_arr_Footnote_EndingTag["value"]; ?></span>
                </p>

                <div class="footnote_placeholder_box_example">
                    <p>
                        <span
                            class="footnote_highlight_placeholder"><?php echo $l_arr_Footnote_StartingTag["value"] . __("example string", FOOTNOTES_PLUGIN_NAME) . $l_arr_Footnote_EndingTag["value"]; ?></span>
                        <?php echo __("will be displayed as:", FOOTNOTES_PLUGIN_NAME); ?>
                        &nbsp;&nbsp;&nbsp;&nbsp;
                        <?php echo footnotes_replaceFootnotes($l_arr_Footnote_StartingTag["value"] . __("example string", FOOTNOTES_PLUGIN_NAME) . $l_arr_Footnote_EndingTag["value"], true, true); ?>
                    </p>
                </div>

                <p>
                    <?php echo sprintf(__("If you have any questions, please don't hesitate to %se-mail%s us.", FOOTNOTES_PLUGIN_NAME), '<a href="mailto:mci@cheret.co.uk" class="footnote_plugin">', '</a>'); ?>
                </p>
            </div>
        </div>
    <?php
    }
} /* Class Class_FootnotesSettings */