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<?php

/*
Use cases:
[button href="/contact" text="contact us"]
[button href="/contact" text="contact us" /]
[button href="/contact"]Contact Us[/button]
[button]<a href="/contact/">Contact Us</a>[/button]

Available shortcode attributes
id, class, style, href, target, rel, text
*/

function shortcode_the_d4_button( $atts, $content = NULL ) {

	$attributes = array(
		'id'     => NULL,
		'class'  => NULL,
		'style'  => NULL,
		'href'   => NULL,
		'target' => NULL,
		'rel'    => NULL,
	);


	//  Shortcode attributes
		$shortcode_attributes = array(
			'text' => 'Click Here',
		);
		$attr = shortcode_atts( array_merge($attributes, $shortcode_attributes), $atts );


	// Build Link Attributes 
		$attr['class'] = 'button ' . $attr['class'];
		$link_attributes = '';
		foreach ( $attributes as $key => $value ) {
			if ( isset($attr[$key]) ) {
				$link_attributes .= ' ' . $key . '="' . trim($attr[$key]) . '"';
			}
		}

	// BUILD OUTPUT
		$output = '';

			// Wrapping a link
			if ( isset($content) && ! empty($content) ) {

				// Content likely contains an <a> tag
				if ( strpos($content, '<a ') !== false ) {
					$content = str_replace('<a ', '<a' . $link_attributes, $content);
					$output .= $content;

				} else {

					$output .= '<a' . $link_attributes . '>';
						$output .= $content;
					$output .= '</a>';

				}

			// No wrapper
			} else {
				$output .= '<a' . $link_attributes . '>';
					$output .= $attr['text'];
				$output .= '</a>';
			}

		return $output;

} add_shortcode('button', 'shortcode_the_d4_button');