WP_Customize_Manager::_publish_changeset_values PHP Method

    public function _publish_changeset_values($changeset_post_id)
    {
        $publishing_changeset_data = $this->get_changeset_post_data($changeset_post_id);
        if (is_wp_error($publishing_changeset_data)) {
            return $publishing_changeset_data;
        }
        $changeset_post = get_post($changeset_post_id);
        /*
         * Temporarily override the changeset context so that it will be read
         * in calls to unsanitized_post_values() and so that it will be available
         * on the $wp_customize object passed to hooks during the save logic.
         */
        $previous_changeset_post_id = $this->_changeset_post_id;
        $this->_changeset_post_id = $changeset_post_id;
        $previous_changeset_uuid = $this->_changeset_uuid;
        $this->_changeset_uuid = $changeset_post->post_name;
        $previous_changeset_data = $this->_changeset_data;
        $this->_changeset_data = $publishing_changeset_data;
        // Parse changeset data to identify theme mod settings and user IDs associated with settings to be saved.
        $setting_user_ids = array();
        $theme_mod_settings = array();
        $namespace_pattern = '/^(?P<stylesheet>.+?)::(?P<setting_id>.+)$/';
        $matches = array();
        foreach ($this->_changeset_data as $raw_setting_id => $setting_params) {
            $actual_setting_id = null;
            $is_theme_mod_setting = isset($setting_params['value']) && isset($setting_params['type']) && 'theme_mod' === $setting_params['type'] && preg_match($namespace_pattern, $raw_setting_id, $matches);
            if ($is_theme_mod_setting) {
                if (!isset($theme_mod_settings[$matches['stylesheet']])) {
                    $theme_mod_settings[$matches['stylesheet']] = array();
                }
                $theme_mod_settings[$matches['stylesheet']][$matches['setting_id']] = $setting_params;
                if ($this->get_stylesheet() === $matches['stylesheet']) {
                    $actual_setting_id = $matches['setting_id'];
                }
            } else {
                $actual_setting_id = $raw_setting_id;
            }
            // Keep track of the user IDs for settings actually for this theme.
            if ($actual_setting_id && isset($setting_params['user_id'])) {
                $setting_user_ids[$actual_setting_id] = $setting_params['user_id'];
            }
        }
        $changeset_setting_values = $this->unsanitized_post_values(array('exclude_post_data' => true, 'exclude_changeset' => false));
        $changeset_setting_ids = array_keys($changeset_setting_values);
        $this->add_dynamic_settings($changeset_setting_ids);
        /**
         * Fires once the theme has switched in the Customizer, but before settings
         * have been saved.
         *
         * @since 3.4.0
         *
         * @param WP_Customize_Manager $manager WP_Customize_Manager instance.
         */
        do_action('customize_save', $this);
        /*
         * Ensure that all settings will allow themselves to be saved. Note that
         * this is safe because the setting would have checked the capability
         * when the setting value was written into the changeset. So this is why
         * an additional capability check is not required here.
         */
        $original_setting_capabilities = array();
        foreach ($changeset_setting_ids as $setting_id) {
            $setting = $this->get_setting($setting_id);
            if ($setting && !isset($setting_user_ids[$setting_id])) {
                $original_setting_capabilities[$setting->id] = $setting->capability;
                $setting->capability = 'exist';
            }
        }
        $original_user_id = get_current_user_id();
        foreach ($changeset_setting_ids as $setting_id) {
            $setting = $this->get_setting($setting_id);
            if ($setting) {
                /*
                 * Set the current user to match the user who saved the value into
                 * the changeset so that any filters that apply during the save
                 * process will respect the original user's capabilities. This
                 * will ensure, for example, that KSES won't strip unsafe HTML
                 * when a scheduled changeset publishes via WP Cron.
                 */
                if (isset($setting_user_ids[$setting_id])) {
                    wp_set_current_user($setting_user_ids[$setting_id]);
                } else {
                    wp_set_current_user($original_user_id);
                }
                $setting->save();
            }
        }
        wp_set_current_user($original_user_id);
        // Update the stashed theme mod settings, removing the active theme's stashed settings, if activated.
        if (did_action('switch_theme')) {
            $other_theme_mod_settings = $theme_mod_settings;
            unset($other_theme_mod_settings[$this->get_stylesheet()]);
            $this->update_stashed_theme_mod_settings($other_theme_mod_settings);
        }
        /**
         * Fires after Customize settings have been saved.
         *
         * @since 3.6.0
         *
         * @param WP_Customize_Manager $manager WP_Customize_Manager instance.
         */
        do_action('customize_save_after', $this);
        // Restore original capabilities.
        foreach ($original_setting_capabilities as $setting_id => $capability) {
            $setting = $this->get_setting($setting_id);
            if ($setting) {
                $setting->capability = $capability;
            }
        }
        // Restore original changeset data.
        $this->_changeset_data = $previous_changeset_data;
        $this->_changeset_post_id = $previous_changeset_post_id;
        $this->_changeset_uuid = $previous_changeset_uuid;
        return true;
    }