WordPress shortcode to show button

shortcode-button.php

<?php

/**
 *
 * Add a new custom button.
 * Usage [custombutton url="https://www.nuno-sarmento.com/" target="self" text="Go To NS"].
 */
// @codingStandardsIgnoreStart
function ns_custom_button_shortcode( $atts, $content = null ) {
    // shortcode attributes
    extract( shortcode_atts( array(
        'url'    => '',
        'title'  => '',
        'target' => '',
        'text'   => '',
    ), $atts ) );

    $content = $text ? $text : $content;
    // Returns the button with a link
    if ( $url ) {
        $link_attr = array(
            'href'   => esc_url( $url ),
            'title'  => esc_attr( $title ),
            'target' => ( 'blank' == $target ) ? '_blank' : '',
            'class'  => 'custombutton'
        );
        $link_attrs_str = '';
        foreach ( $link_attr as $key => $val ) {
            if ( $val ) {
                $link_attrs_str .= ' ' . $key . '="' . $val . '"';
            }
        }
        return '<a' . $link_attrs_str . '><span>' . do_shortcode( $content ) . '</span></a>';
    }
    // Return as span when no link defined
    else {
        return '<span class="custombutton"><span>' . do_shortcode( $content ) . '</span></span>';
    }
}
add_shortcode( 'custombutton', 'ns_custom_button_shortcode' );
// @codingStandardsIgnoreEnd