Refactor server-side block support flags support

lib/block-supports/align.php

@@ -0,0 +1,46 @@
+<?php
+/**
+ * Align block support flag.
+ *
+ * @package gutenberg
+ */
+
+/**
+ * Registers the attributes block attribute for block types that support it.
+ *
+ * @param  array $block_type Block Type.
+ */
+function gutenberg_register_alignment_support( $block_type ) {
+	$has_align_support = gutenberg_experimental_get( $block_type->supports, array( 'align' ), false );
+	if ( $has_align_support ) {
+		if ( ! $block_type->attributes ) {
+			$block_type->attributes = array();
+		}
+
+		$block_type->attributes['align'] = array(
+			'type' => 'string',
+			'enum' => array( 'left', 'center', 'right', 'wide', 'full', '' ),
+		);
+	}
+}
+
+/**
+ * Add CSS classes for block alignment to the incoming attributes array.
+ * This will be applied to the block markup in the front-end.
+ *
+ * @param  array $attributes comprehensive list of attributes to be applied.
+ * @param  array $block_attributes block attributes.
+ * @param  array $block_type Block Type.
+ * @return array Block alignment CSS classes and inline styles.
+ */
+function gutenberg_apply_alignment_support( $attributes, $block_attributes, $block_type ) {
+	if ( $block_type->supports && array_key_exists( 'align', $block_type->supports ) ) {
+		$has_block_alignment = array_key_exists( 'align', $block_attributes );
+
+		if ( $has_block_alignment ) {
+			$attributes['css_classes'][] = sprintf( 'align%s', $block_attributes['align'] );
+		}
+	}
+
+	return $attributes;
+}

lib/block-supports/colors.php

@@ -0,0 +1,94 @@
+<?php
+/**
+ * Colors block support flag.
+ *
+ * @package gutenberg
+ */
+
+/**
+ * Add CSS classes and inline styles for colors to the incoming attributes array.
+ * This will be applied to the block markup in the front-end.
+ *
+ * @param  array $attributes comprehensive list of attributes to be applied.
+ * @param  array $block_attributes block attributes.
+ * @param  array $block_type Block type.
+ * @return array Colors CSS classes and inline styles.
+ */
+function gutenberg_apply_colors_support( $attributes, $block_attributes, $block_type ) {
+	$color_support                 = gutenberg_experimental_get( $block_type->supports, array( '__experimentalColor' ), false );
+	$has_text_colors_support       = is_array( $color_support ) || $color_support;
+	$has_background_colors_support = $has_text_colors_support;
+	$has_link_colors_support       = $has_text_colors_support && gutenberg_experimental_get( $color_support, array( 'linkColor' ), false );
+	$has_gradients_support         = $has_text_colors_support && gutenberg_experimental_get( $color_support, array( 'gradients' ), false );
+
+	// Text Colors.
+	// Check support for text colors.
+	if ( $has_text_colors_support ) {
+		$has_named_text_color  = array_key_exists( 'textColor', $block_attributes );
+		$has_custom_text_color = isset( $block_attributes['style']['color']['text'] );
+
+		// Apply required generic class.
+		if ( $has_custom_text_color || $has_named_text_color ) {
+			$attributes['css_classes'][] = 'has-text-color';
+		}
+		// Apply color class or inline style.
+		if ( $has_named_text_color ) {
+			$attributes['css_classes'][] = sprintf( 'has-%s-color', $block_attributes['textColor'] );
+		} elseif ( $has_custom_text_color ) {
+			$attributes['inline_styles'][] = sprintf( 'color: %s;', $block_attributes['style']['color']['text'] );
+		}
+	}
+
+	// Link Colors.
+	if ( $has_link_colors_support ) {
+		$has_link_color = isset( $block_attributes['style']['color']['link'] );
+		// Apply required class and style.
+		if ( $has_link_color ) {
+			$attributes['css_classes'][] = 'has-link-color';
+			// If link is a named color.
+			if ( strpos( $block_attributes['style']['color']['link'], 'var:preset|color|' ) !== false ) {
+				// Get the name from the string and add proper styles.
+				$index_to_splice               = strrpos( $block_attributes['style']['color']['link'], '|' ) + 1;
+				$link_color_name               = substr( $block_attributes['style']['color']['link'], $index_to_splice );
+				$attributes['inline_styles'][] = sprintf( '--wp--style--color--link:var(--wp--preset--color--%s);', $link_color_name );
+			} else {
+				$attributes['inline_styles'][] = sprintf( '--wp--style--color--link: %s;', $block_attributes['style']['color']['link'] );
+			}
+		}
+	}
+
+	// Background Colors.
+	if ( $has_background_colors_support ) {
+		$has_named_background_color  = array_key_exists( 'backgroundColor', $block_attributes );
+		$has_custom_background_color = isset( $block_attributes['style']['color']['background'] );
+
+		// Apply required background class.
+		if ( $has_custom_background_color || $has_named_background_color ) {
+			$attributes['css_classes'][] = 'has-background';
+		}
+		// Apply background color classes or styles.
+		if ( $has_named_background_color ) {
+			$attributes['css_classes'][] = sprintf( 'has-%s-background-color', $block_attributes['backgroundColor'] );
+		} elseif ( $has_custom_background_color ) {
+			$attributes['inline_styles'][] = sprintf( 'background-color: %s;', $block_attributes['style']['color']['background'] );
+		}
+	}
+
+	// Gradients.
+	if ( $has_gradients_support ) {
+		$has_named_gradient  = array_key_exists( 'gradient', $block_attributes );
+		$has_custom_gradient = isset( $block_attributes['style']['color']['gradient'] );
+
+		if ( $has_named_gradient || $has_custom_gradient ) {
+			$attributes['css_classes'][] = 'has-background';
+		}
+		// Apply required background class.
+		if ( $has_named_gradient ) {
+			$attributes['css_classes'][] = sprintf( 'has-%s-gradient-background', $block_attributes['gradient'] );
+		} elseif ( $has_custom_gradient ) {
+			$attributes['inline_styles'][] = sprintf( 'background: %s;', $block_attributes['style']['color']['gradient'] );
+		}
+	}
+
+	return $attributes;
+}

lib/block-supports/index.php

@@ -0,0 +1,89 @@
+<?php
+/**
+ * Block support flags.
+ *
+ * @package gutenberg
+ */
+
+/**
+ * Filter the registered blocks to apply the block supports attributes registration.
+ */
+function gutenberg_register_block_supports() {
+	$block_registry         = WP_Block_Type_Registry::get_instance();
+	$registered_block_types = $block_registry->get_all_registered();
+	// Ideally we need a hook to extend the block registration
+	// instead of mutating the block type.
+	foreach ( $registered_block_types as $block_type ) {
+		gutenberg_register_alignment_support( $block_type );
+	}
+}
+
+add_action( 'init', 'gutenberg_register_block_supports', 21 );
+
+/**
+ * Filters the frontend output of blocks and apply the block support flags transformations.
+ *
+ * @param  string $block_content rendered block content.
+ * @param  array  $block block object.
+ * @return string filtered block content.
+ */
+function gutenberg_apply_block_supports( $block_content, $block ) {
+	if ( ! isset( $block['attrs'] ) ) {
+		return $block_content;
+	}
+
+	$block_type = WP_Block_Type_Registry::get_instance()->get_registered( $block['blockName'] );
+	// If no render_callback, assume styles have been previously handled.
+	if ( ! $block_type || ! $block_type->render_callback ) {
+		return $block_content;
+	}
+
+	$attributes = array();
+	$attributes = gutenberg_apply_colors_support( $attributes, $block['attrs'], $block_type );
+	$attributes = gutenberg_apply_typography_support( $attributes, $block['attrs'], $block_type );
+	$attributes = gutenberg_apply_alignment_support( $attributes, $block['attrs'], $block_type );
+
+	if ( ! count( $attributes ) ) {
+		return $block_content;
+	}
+
+	$dom = new DOMDocument( '1.0', 'utf-8' );
+
+	// Suppress warnings from this method from polluting the front-end.
+	// @codingStandardsIgnoreStart
+	if ( ! @$dom->loadHTML( $block_content, LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD | LIBXML_COMPACT ) ) {
+	// @codingStandardsIgnoreEnd
+		return $block_content;
+	}
+
+	$xpath      = new DOMXPath( $dom );
+	$block_root = $xpath->query( '/*' )[0];
+
+	if ( empty( $block_root ) ) {
+		return $block_content;
+	}
+
+	// Some inline styles may be added without ending ';', add this if necessary.
+	$current_styles = trim( $block_root->getAttribute( 'style' ), ' ' );
+	if ( strlen( $current_styles ) > 0 && substr( $current_styles, -1 ) !== ';' ) {
+		$current_styles = $current_styles . ';';
+	};
+
+	// Merge and dedupe new and existing classes and styles.
+	$classes_to_add = esc_attr( implode( ' ', array_key_exists( 'css_classes', $attributes ) ? $attributes['css_classes'] : array() ) );
+	$styles_to_add  = esc_attr( implode( ' ', array_key_exists( 'inline_styles', $attributes ) ? $attributes['inline_styles'] : array() ) );
+	$new_classes    = implode( ' ', array_unique( explode( ' ', ltrim( $block_root->getAttribute( 'class' ) . ' ' ) . $classes_to_add ) ) );
+	$new_styles     = implode( ' ', array_unique( explode( ' ', $current_styles . ' ' . $styles_to_add ) ) );
+
+	// Apply new styles and classes.
+	if ( ! empty( $new_classes ) ) {
+		$block_root->setAttribute( 'class', $new_classes );
+	}
+
+	if ( ! empty( $new_styles ) ) {
+		$block_root->setAttribute( 'style', $new_styles );
+	}
+
+	return $dom->saveHtml();
+}
+add_filter( 'render_block', 'gutenberg_apply_block_supports', 10, 2 );

lib/block-supports/typography.php

@@ -0,0 +1,44 @@
+<?php
+/**
+ * Typography block support flag.
+ *
+ * @package gutenberg
+ */
+
+/**
+ * Add CSS classes and inline styles for font sizes to the incoming attributes array.
+ * This will be applied to the block markup in the front-end.
+ *
+ * @param  array $attributes comprehensive list of attributes to be applied.
+ * @param  array $block_attributes block attributes.
+ * @param  array $block_type block type.
+ * @return array Font size CSS classes and inline styles.
+ */
+function gutenberg_apply_typography_support( $attributes, $block_attributes, $block_type ) {
+	$has_font_size_support   = gutenberg_experimental_get( $block_type->supports, array( '__experimentalFontSize' ), false );
+	$has_line_height_support = gutenberg_experimental_get( $block_type->supports, array( '__experimentalLineHeight' ), false );
+
+	// Font Size.
+	if ( $has_font_size_support ) {
+		$has_named_font_size  = array_key_exists( 'fontSize', $block_attributes );
+		$has_custom_font_size = isset( $block_attributes['style']['typography']['fontSize'] );
+
+		// Apply required class or style.
+		if ( $has_named_font_size ) {
+			$attributes['css_classes'][] = sprintf( 'has-%s-font-size', $block_attributes['fontSize'] );
+		} elseif ( $has_custom_font_size ) {
+			$attributes['inline_styles'][] = sprintf( 'font-size: %spx;', $block_attributes['style']['typography']['fontSize'] );
+		}
+	}
+
+	// Line Height.
+	if ( $has_line_height_support ) {
+		$has_line_height = isset( $block_attributes['style']['typography']['lineHeight'] );
+		// Add the style (no classes for line-height).
+		if ( $has_line_height ) {
+			$attributes['inline_styles'][] = sprintf( 'line-height: %s;', $block_attributes['style']['typography']['lineHeight'] );
+		}
+	}
+
+	return $attributes;
+}