Add inline file delivery to WC_Download_Handler (#31145)

Add inline file delivery to WC_Download_Handler

Create a new setting option for inline file delivery for downloadable
products. In the Download Handler create a new method for the new
setting as well as a method for returning the proper headers to deliver
files inline.

Resolves: #28410

* Update Content Type of inline delivered files

* Update Downloaded file name

* Change content-disposition to be a checkbox

Since inline-delivery works with multiple download methods

* Document  function

* Add new setting for test, see #31145.

* Better setting wording and remove typo comment.

* Address pr feedback.

* Add changelog.

* Rephrase the settings to make it more clear.

* More rephrasing.

Co-authored-by: Matthew Caldwell <caldwellysr@gmail.com>

plugins/woocommerce/changelog/allow-inline-downloads

@@ -0,0 +1,4 @@
+Significance: minor
+Type: enhancement
+
+Add option to serve downloadable files inline.

plugins/woocommerce/includes/admin/settings/class-wc-settings-products.php

@@ -421,6 +421,16 @@ class WC_Settings_Products extends WC_Settings_Page {
 					'autoload'      => false,
 				),
 
+				array(
+					'title'    => __( 'Open in browser', 'woocommerce' ),
+					'desc'     => __( 'Open downloadable files in the browser, instead of saving them to the device.', 'woocommerce' ),
+					'id'       => 'woocommerce_downloads_deliver_inline',
+					'type'     => 'checkbox',
+					'default'  => false,
+					'desc_tip' => __( 'Customers can still save the file to their device, but by default file will be opened instead of being downloaded (does not work with redirects).', 'woocommerce' ),
+					'autoload' => false,
+				),
+
 				array(
 					'title'    => __( 'Filename', 'woocommerce' ),
 					'desc'     => __( 'Append a unique string to filename for security', 'woocommerce' ),

plugins/woocommerce/includes/class-wc-download-handler.php

@@ -522,7 +522,7 @@ class WC_Download_Handler {
 		header( 'X-Robots-Tag: noindex, nofollow', true );
 		header( 'Content-Type: ' . self::get_download_content_type( $file_path ) );
 		header( 'Content-Description: File Transfer' );
-		header( 'Content-Disposition: attachment; filename="' . $filename . '";' );
+		header( 'Content-Disposition: ' . self::get_content_disposition() . '; filename="' . $filename . '";' );
 		header( 'Content-Transfer-Encoding: binary' );
 
 		$file_size = @filesize( $file_path ); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged
@@ -578,6 +578,22 @@ class WC_Download_Handler {
 		}
 	}
 
+	/**
+	 *
+	 * Get selected content disposition
+	 *
+	 * Defaults to attachment if `woocommerce_downloads_deliver_inline` setting is not selected.
+	 *
+	 * @return string Content disposition value.
+	 */
+	private static function get_content_disposition() : string {
+		$disposition = 'attachment';
+		if ( 'yes' === get_option( 'woocommerce_downloads_deliver_inline' ) ) {
+			$disposition = 'inline';
+		}
+		return $disposition;
+	}
+
 	/**
 	 * Read file chunked.
 	 *

plugins/woocommerce/tests/php/includes/settings/class-wc-settings-products-test.php

@@ -147,6 +147,7 @@ class WC_Settings_Products_Test extends WC_Settings_Unit_Test_Case {
 			'woocommerce_downloads_require_login'              => 'checkbox',
 			'woocommerce_downloads_grant_access_after_payment' => 'checkbox',
 			'woocommerce_downloads_add_hash_to_filename'       => 'checkbox',
+			'woocommerce_downloads_deliver_inline'             => 'checkbox',
 		);
 
 		$this->assertEquals( $expected, $settings_ids_and_types );