Add --format support to language core install command

features/language-core.feature

@@ -476,3 +476,50 @@ Feature: Manage core translation files for a WordPress install
         | en_US     | active     |
         | nl_NL     | installed  |
     And STDERR should be empty
+
+  @require-wp-4.0
+  Scenario: Install languages with different output formats
+    Given a WP install
+    And an empty cache
+
+    When I run `wp language core install de_DE nl_NL --format=csv`
+    Then the return code should be 0
+    And STDOUT should be:
+      """
+      locale,status
+      de_DE,installed
+      nl_NL,installed
+      """
+    And STDERR should be empty
+
+    When I run `wp language core install de_DE nl_NL --format=summary`
+    Then the return code should be 0
+    And STDOUT should contain:
+      """
+      Success: Installed 0 of 2 languages (2 skipped).
+      """
+    And STDERR should be empty
+
+    When I run `wp language core install de_DE nl_NL invalid_lang --format=json`
+    Then the return code should be 0
+    And STDOUT should be JSON containing:
+      """
+      [{"locale":"de_DE","status":"already installed"},{"locale":"nl_NL","status":"already installed"},{"locale":"invalid_lang","status":"not available"}]
+      """
+    And STDERR should be empty
+
+    When I run `wp language core install fr_FR --format=table`
+    Then the return code should be 0
+    And STDOUT should contain:
+      """
+      locale
+      """
+    And STDOUT should contain:
+      """
+      fr_FR
+      """
+    And STDOUT should contain:
+      """
+      installed
+      """
+    And STDERR should be empty

src/Core_Language_Command.php

@@ -183,6 +183,16 @@
 	 * [--activate]
 	 * : If set, the language will be activated immediately after install.
 	 *
+	 * [--format=<format>]
+	 * : Render output in a particular format (for one or more languages).
+	 * ---
+	 * options:
+	 *   - table
+	 *   - csv
+	 *   - json
+	 *   - summary
+	 * ---
+	 *
 	 * ## EXAMPLES
 	 *
 	 *     # Install the Brazilian Portuguese language.
@@ -198,7 +208,7 @@
 	 * @subcommand install
 	 *
 	 * @param string[] $args Positional arguments.
-	 * @param array{activate?: bool} $assoc_args Associative arguments.
+	 * @param array{activate?: bool, format?: string} $assoc_args Associative arguments.
 	 */
 	public function install( $args, $assoc_args ) {
 		$language_codes = (array) $args;
@@ -208,15 +218,34 @@
 			WP_CLI::error( 'Only a single language can be active.' );
 		}
 
+		$has_format_flag = isset( $assoc_args['format'] );
+
+		if ( $has_format_flag ) {
+			if ( in_array( $assoc_args['format'], array( 'json', 'csv' ), true ) ) {
+				$logger = new \WP_CLI\Loggers\Quiet();
+				\WP_CLI::set_logger( $logger );
+			}
+		}
+
 		$available = $this->get_installed_languages();
 
+		$results = array();
+
 		$successes = 0;
 		$errors    = 0;
 		$skips     = 0;
 		foreach ( $language_codes as $language_code ) {
+			if ( $has_format_flag ) {
+				$result = [
+					'locale' => $language_code,
+				];
+			}
 
 			if ( in_array( $language_code, $available, true ) ) {
 				\WP_CLI::log( "Language '{$language_code}' already installed." );
+				if ( $has_format_flag ) {
+					$result['status'] = 'already installed';
+				}
 				++$skips;
 			} else {
 				$response = $this->download_language_pack( $language_code );
@@ -227,19 +256,38 @@
 
 					// Skip if translation is not yet available.
 					if ( 'not_found' === $response->get_error_code() ) {
+						if ( $has_format_flag ) {
+							$result['status'] = 'not available';
+						}
 						++$skips;
 					} else {
+						if ( $has_format_flag ) {
+							$result['status'] = 'not installed';
+						}
 						++$errors;
 					}
 				} else {
 					\WP_CLI::log( "Language '{$language_code}' installed." );
+					if ( $has_format_flag ) {
+						$result['status'] = 'installed';
+					}
 					++$successes;
 				}
 			}
 
 			if ( WP_CLI\Utils\get_flag_value( $assoc_args, 'activate' ) ) {
 				$this->activate_language( $language_code );
 			}
+
+			if ( $has_format_flag ) {
+				$results[] = (object) $result;
+			}
+		}
+
+		if ( $has_format_flag ) {
+			if ( 'summary' !== $assoc_args['format'] ) {
+				\WP_CLI\Utils\format_items( $assoc_args['format'], $results, array( 'locale', 'status' ) );
+			}
 		}
 
 		\WP_CLI\Utils\report_batch_operation_results( 'language', 'install', $count, $successes, $errors, $skips );
@@ -307,7 +355,7 @@
 			// As of WP 4.0, no API for deleting a language pack
 			WP_Filesystem();
 			$deleted = false;
 			foreach ( $files as $file ) {
 				if ( '.' === $file[0] || is_dir( $file ) ) {
 					continue;
 				}