Blocks: allow multi-line submit buttons (#11223)

* Allows the contact form block and subscription form block to display
multi-line submit buttons on the front end.

* clean-up some bad mark-up

* addressing feedback from @enejb and @jeherve

modules/contact-form/grunion-contact-form.php

@@ -139,7 +139,7 @@ protected function __construct() {
 		) {
 			add_filter( 'widget_text', array( $this, 'widget_shortcode_hack' ), 5 );
 		}
-		
+
 		add_filter( 'jetpack_contact_form_is_spam', array( $this, 'is_spam_blacklist' ), 10, 2 );
 
 		// Akismet to the rescue
@@ -634,7 +634,7 @@ function widget_shortcode_hack( $text ) {
 
 		return $text;
 	}
-	
+
 	/**
 	 * Check if a submission matches the Comment Blacklist.
 	 * The Comment Blacklist is a means to moderate discussion, and contact
@@ -650,11 +650,11 @@ function is_spam_blacklist( $is_spam, $form = array() ) {
 		if ( $is_spam ) {
 			return $is_spam;
 		}
-		
+
 		if ( wp_blacklist_check( $form['comment_author'], $form['comment_author_email'], $form['comment_author_url'], $form['comment_content'], $form['user_ip'], $form['user_agent'] ) ) {
 			return true;
 		}
-		
+
 		return false;
 	}
 
@@ -1802,6 +1802,11 @@ class Grunion_Contact_Form extends Crunion_Contact_Form_Shortcode {
 	 */
 	static $style = false;
 
+	/**
+	 * @var array When printing the submit button, what tags are allowed
+	 */
+	static $allowed_html_tags_for_submit_button = array( 'br' => array() );
+
 	function __construct( $attributes, $content = null ) {
 		global $post;
 
@@ -2060,12 +2065,16 @@ static function parse( $attributes, $content ) {
 				$submit_button_text = $form->get_attribute( 'submit_button_text' );
 			}
 
-			$r .= "\t\t<input type='submit' value='" . esc_attr( $submit_button_text ) . "' class='" . esc_attr( $submit_button_class ) . "'";
+			$r .= "\t\t<button type='submit' class='" . esc_attr( $submit_button_class ) . "'";
 			if ( ! empty( $submit_button_styles ) ) {
 				$r .= " style='" . esc_attr( $submit_button_styles ) . "'";
 			}
-			$r .= "/>\n";
-
+			$r .= ">";
+			$r .= wp_kses(
+				      $submit_button_text,
+				      self::$allowed_html_tags_for_submit_button
+			      ) . "</button>";
+
 			if ( is_user_logged_in() ) {
 				$r .= "\t\t" . wp_nonce_field( 'contact-form_' . $id, '_wpnonce', true, false ) . "\n"; // nonce and referer
 			}

modules/subscriptions/views.php

@@ -2,6 +2,10 @@
 
 class Jetpack_Subscriptions_Widget extends WP_Widget {
 	static $instance_count = 0;
+	/**
+	 * @var array When printing the submit button, what tags are allowed
+	 */
+	static $allowed_html_tags_for_submit_button = array( 'br' => array() );
 
 	function __construct() {
 		$widget_ops = array(
@@ -289,14 +293,21 @@ static function render_widget_subscription_form( $args, $instance, $subscribe_em
                     <input type="hidden" name="sub-type" value="<?php echo esc_attr( $source ); ?>"/>
                     <input type="hidden" name="redirect_fragment" value="<?php echo esc_attr( $widget_id ); ?>"/>
 					<?php wp_nonce_field( 'blogsub_subscribe_' . $current_blog->blog_id, '_wpnonce', false ); ?>
-                    <input type="submit" value="<?php echo esc_attr( $subscribe_button ); ?>"
+                    <button type="submit"
 	                    <?php if ( ! empty( $submit_button_classes ) ) { ?>
 	                        class="<?php echo esc_attr( $submit_button_classes ); ?>"
 	                    <?php }; ?>
 		                <?php if ( ! empty( $submit_button_styles ) ) { ?>
 			                style="<?php echo esc_attr( $submit_button_styles ); ?>"
 		                <?php }; ?>
-	                />
+	                >
+	                    <?php
+	                    echo wp_kses(
+		                    $subscribe_button,
+		                    self::$allowed_html_tags_for_submit_button
+	                    );
+	                    ?>
+                    </button>
                 </p>
             </form>
 			<?php
@@ -349,15 +360,21 @@ class="screen-reader-text"
 							wp_nonce_field( 'blogsub_subscribe_' . get_current_blog_id(), '_wpnonce', false );
 						}
 						?>
-                        <input type="submit" value="<?php echo esc_attr( $subscribe_button ); ?>"
+                        <button type="submit"
 	                        <?php if ( ! empty( $submit_button_classes ) ) { ?>
 	                            class="<?php echo esc_attr( $submit_button_classes ); ?>"
                             <?php }; ?>
 		                    <?php if ( ! empty( $submit_button_styles ) ) { ?>
 			                    style="<?php echo esc_attr( $submit_button_styles ); ?>"
 		                    <?php }; ?>
 	                        name="jetpack_subscriptions_widget"
-	                    />
+	                    >
+	                        <?php
+	                        echo wp_kses(
+		                        $subscribe_button,
+		                        self::$allowed_html_tags_for_submit_button
+	                        ); ?>
+                        </button>
                     </p>
 				<?php } ?>
             </form>