Merge pull request #136 from humanmade/tachyon-provider

Add Tachyon Provider for AMF WP

composer.json

@@ -17,10 +17,13 @@
 		"humanmade/gaussholder": "1.1.3",
 		"humanmade/aws-rekognition": "~0.1.7",
 		"humanmade/rename-images-command": "^0.1.0",
-		"humanmade/asset-manager-framework": "^0.11.0",
+		"humanmade/asset-manager-framework": "^0.12.0",
 		"humanmade/amf-wordpress": "^0.2.0"
 	},
 	"autoload": {
+		"classmap": [
+			"inc/"
+		],
 		"files": [
 			"inc/namespace.php",
 			"inc/global_assets/namespace.php"

docs/asset-manager-framework.md

@@ -113,19 +113,58 @@ add_action( 'amf/register_providers', function ( ProviderRegistry $provider_regi
 
 For a more complete example using Unsplash see the [AMF Unsplash integration plugin](https://github.com/humanmade/amf-unsplash) for reference.
 
-### Extending Existing Providers
+### Dynamic Image Resizing
 
-Since you have access to each provider instance during registration via the `amf/provider` filter, you can also use it and decorate it:
+AMF provides an interface to enable dynamic image resizing for your provider classes. The Global Media Library uses this to deliver assets via Tachyon out of the box.
+
+To make a provider that can resize assets on the fly it needs to implement the `Resize` interface:
+
+```php
+use UnsplashProvider;
+use AssetManagerFramework\Interfaces\{
+    Resize
+};
+
+class ResizingUnsplashProvider extends UnsplashProvider implements Resize {
+
+    public function resize( WP_Post $attachment, int $width, int $height, $crop = false ) : string {
+
+        $base_url = wp_get_attachment_url( $attachment->ID );
+
+        $query_args = [
+            'w' => $width,
+            'h' => $height,
+            'fit' => $crop ? 'crop' : 'clip',
+            'crop' => 'faces,focalpoint',
+        ];
+
+        if ( is_array( $crop ) ) {
+            $crop = array_filter( $crop, function ( $value ) {
+                return $value !== 'center';
+            } );
+            $query_args['crop'] = implode( ',', $crop );
+        }
+
+        return add_query_args( urlencode_deep( $query_args ), $base_url );
+    }
+
+}
+```
+
+### Modifying Existing Providers
+
+Since you have access to each provider instance during registration via the `amf/provider` filter, you can also use it and decorate it, replace it with a subclass of a specific provider or replace it entirely:
 
 ```php
 use AssetManagerFramework\Provider;
+use ResizingUnsplashProvider;
 
 add_filter( 'amf/provider', function ( Provider $provider, string $id ) {
     if ( $provider->get_id() !== 'unsplash' ) {
         return $provider;
     }
 
-	return new DecoratingProvider( $provider );
+	return new ResizingUnsplashProvider();
 }, 10, 2 );
 ```
 

inc/global_assets/class-tachyon-provider.php

@@ -0,0 +1,104 @@
+<?php
+/**
+ * Tachyon Provider for Global Assets.
+ *
+ * @package altis/media
+ */
+
+namespace Altis\Media\Global_Assets;
+
+use AMFWordPress\Provider;
+use AssetManagerFramework\Interfaces\Resize;
+use WP_Post;
+
+/**
+ * Tachyon extension for the AMF WordPress provider.
+ */
+class Tachyon_Provider extends Provider implements Resize {
+
+	/**
+	 * Handles resizing of an AMF WordPress attachment.
+	 *
+	 * @param WP_Post $attachment The attachment post.
+	 * @param int $width Target width.
+	 * @param int $height Target height.
+	 * @param bool|array $crop If truthy crop to the given dimensions, can be a non-associative
+	 *                         array of x and y positions where x is 'left', 'center' or 'right'
+	 *                         and y is 'top', 'center' or 'bottom'.
+	 * @return string The resized asset URL.
+	 */
+	public function resize( WP_Post $attachment, int $width, int $height, $crop = false ) : string {
+		// Determine resize method.
+		$method = $crop ? 'resize' : 'fit';
+
+		$tachyon_args = [
+			$method => "{$width},{$height}",
+		];
+
+		// If crop is true.
+		if ( $crop ) {
+			if ( is_array( $crop ) ) {
+				$tachyon_args['gravity'] = implode( '', array_map( function ( $v ) {
+					$map = [
+						'top' => 'north',
+						'center' => '',
+						'bottom' => 'south',
+						'left' => 'west',
+						'right' => 'east',
+					];
+					return $map[ $v ];
+				}, array_reverse( $crop ) ) );
+			} else {
+				$tachyon_args = array_merge(
+					$tachyon_args,
+					$this->get_crop( $attachment, $width, $height )
+				);
+			}
+		}
+
+		$url = add_query_arg(
+			urlencode_deep( $tachyon_args ),
+			wp_get_attachment_url( $attachment->ID )
+		);
+
+		return $url;
+	}
+
+	/**
+	 * Get Tachyon crop arguments.
+	 *
+	 * Uses focal point meta data if provided.
+	 *
+	 * @param WP_Post $attachment The attachment post.
+	 * @param integer $width The crop width.
+	 * @param integer $height The crop height.
+	 * @return array
+	 */
+	protected function get_crop( WP_Post $attachment, int $width, int $height ) : array {
+		$metadata = wp_get_attachment_metadata( $attachment->ID, true );
+
+		$focal_point = get_post_meta( $attachment->ID, '_focal_point', true );
+
+		if ( ! empty( $focal_point ) ) {
+			// Get max size of crop aspect ratio within original image.
+			$dimensions = wp_constrain_dimensions( $width, $height, $metadata['width'], $metadata['height'] );
+
+			if ( $dimensions[0] === $metadata['width'] && $dimensions[1] === $metadata['height'] ) {
+				return [];
+			}
+
+			$crop = [];
+			$crop['width']  = $dimensions[0];
+			$crop['height'] = $dimensions[1];
+
+			// Set x & y but constrain within original image bounds.
+			$crop['x'] = min( $metadata['width'] - $crop['width'], max( 0, $focal_point['x'] - ( $crop['width'] / 2 ) ) );
+			$crop['y'] = min( $metadata['height'] - $crop['height'], max( 0, $focal_point['y'] - ( $crop['height'] / 2 ) ) );
+
+			return [ 'crop' => sprintf( '%dpx,%dpx,%dpx,%dpx', $crop['x'], $crop['y'], $crop['width'], $crop['height'] ) ];
+		} else {
+			return [ 'crop_strategy' => 'smart' ];
+		}
+	}
+
+}

inc/global_assets/namespace.php

@@ -10,6 +10,8 @@
 use Altis;
 use Altis\Global_Content;
 use Altis\Media;
+use AMFWordPress\Factory;
+use AssetManagerFramework\Provider;
 use WP_Post;
 
 /**
@@ -38,6 +40,11 @@ function bootstrap() {
 		return;
 	}
 
+	// Use Tachyon Provider.
+	if ( $config['tachyon'] ) {
+		add_filter( 'amf/provider', __NAMESPACE__ . '\\use_tachyon_provider' );
+	}
+
 	// Configure the global media site.
 	add_action( 'plugins_loaded', __NAMESPACE__ . '\\configure_site', 9 );
 	add_filter( 'altis.core.global_content_site_menu_pages', __NAMESPACE__ . '\\allow_media_pages' );
@@ -81,6 +88,21 @@ function maybe_load_amf_wp() {
 	require_once Altis\ROOT_DIR . '/vendor/humanmade/amf-wordpress/plugin.php';
 }
 
+/**
+ * Overrride the WordPress AMF Provider.
+ *
+ * @param Provider $provider The registered provider.
+ * @return Provider
+ */
+function use_tachyon_provider( Provider $provider ) : Provider {
+	// phpcs:ignore WordPress.WP.CapitalPDangit.Misspelled
+	if ( $provider->get_id() !== 'wordpress' ) {
+		return $provider;
+	}
+
+	return new Tachyon_Provider( new Factory() );
+}
+
 /**
  * Create the Global Media Library site.
  */
@@ -149,7 +171,7 @@ function pre_upload_global_site_link() : void {
  */
 function is_global_asset( int $attachment_id ) : bool {
 	// phpcs:ignore WordPress.WP.CapitalPDangit.Misspelled
-	return get_post_meta( $attachment_id, 'amf_provider', true ) === 'wordpress';
+	return get_post_meta( $attachment_id, '_amf_provider', true ) === 'wordpress';
 }
 
 /**