Enable recursive partials in TemplateParser

Recursive partials are the only way to handle tree-like structures
such as nested lists. Allow setting FLAG_RUNTIMEPARTIAL in LightnCandy
so they can be used.

Since this has a slight performance impact (makes partial invocations
evaluation-time functions calls instead of compilation-time transclusions)
make it optional.

Change-Id: Ie37105a9f1ff92e1a79bfcd9f8578965e3d347f0

diff --git a/includes/TemplateParser.php b/includes/TemplateParser.php
index 2759ff9..2293dab 100644 (file)
--- a/includes/TemplateParser.php
+++ b/includes/TemplateParser.php
@@ -38,6 +38,13 @@ class TemplateParser {
         */
        protected $forceRecompile = false;
 
+       /**
+        * @var int Compilation flags passed to LightnCandy
+        */
+       // Do not add more flags here without discussion.
+       // If you do add more flags, be sure to update unit tests as well.
+       protected $compileFlags = LightnCandy::FLAG_ERROR_EXCEPTION;
+
        /**
         * @param string $templateDir
         * @param bool $forceRecompile
@@ -47,6 +54,18 @@ class TemplateParser {
                $this->forceRecompile = $forceRecompile;
        }
 
+       /**
+        * Enable/disable the use of recursive partials.
+        * @param bool $enable
+        */
+       public function enableRecursivePartials( $enable ) {
+               if ( $enable ) {
+                       $this->compileFlags = $this->compileFlags | LightnCandy::FLAG_RUNTIMEPARTIAL;
+               } else {
+                       $this->compileFlags = $this->compileFlags & ~LightnCandy::FLAG_RUNTIMEPARTIAL;
+               }
+       }
+
        /**
         * Constructs the location of the the source Mustache template
         * @param string $templateName The name of the template
@@ -73,11 +92,13 @@ class TemplateParser {
         * @throws RuntimeException
         */
        protected function getTemplate( $templateName ) {
+               $templateKey = $templateName . '|' . $this->compileFlags;
+
                // If a renderer has already been defined for this template, reuse it
-               if ( isset( $this->renderers[$templateName] ) &&
-                       is_callable( $this->renderers[$templateName] )
+               if ( isset( $this->renderers[$templateKey] ) &&
+                       is_callable( $this->renderers[$templateKey] )
                ) {
-                       return $this->renderers[$templateName];
+                       return $this->renderers[$templateKey];
                }
 
                $filename = $this->getTemplateFilename( $templateName );
@@ -90,7 +111,7 @@ class TemplateParser {
                $fileContents = file_get_contents( $filename );
 
                // Generate a quick hash for cache invalidation
-               $fastHash = md5( $fileContents );
+               $fastHash = md5( $this->compileFlags . '|' . $fileContents );
 
                // Fetch a secret key for building a keyed hash of the PHP code
                $config = MediaWikiServices::getInstance()->getMainConfig();
@@ -127,7 +148,7 @@ class TemplateParser {
                if ( !is_callable( $renderer ) ) {
                        throw new RuntimeException( "Requested template, {$templateName}, is not callable" );
                }
-               $this->renderers[$templateName] = $renderer;
+               $this->renderers[$templateKey] = $renderer;
                return $renderer;
        }
 
@@ -168,9 +189,7 @@ class TemplateParser {
                return LightnCandy::compile(
                        $code,
                        [
-                               // Do not add more flags here without discussion.
-                               // If you do add more flags, be sure to update unit tests as well.
-                               'flags' => LightnCandy::FLAG_ERROR_EXCEPTION,
+                               'flags' => $this->compileFlags,
                                'basedir' => $this->templateDir,
                                'fileext' => '.mustache',
                        ]

diff --git a/tests/phpunit/data/templates/recurse.mustache b/tests/phpunit/data/templates/recurse.mustache
new file mode 100644 (file)
index 0000000..391f227
--- /dev/null
+++ b/tests/phpunit/data/templates/recurse.mustache
@@ -0,0 +1 @@
+r{{#r}}{{>recurse}}{{/r}}
\ No newline at end of file

diff --git a/tests/phpunit/includes/TemplateParserTest.php b/tests/phpunit/includes/TemplateParserTest.php
index 2bd9086..c161f85 100644 (file)
--- a/tests/phpunit/includes/TemplateParserTest.php
+++ b/tests/phpunit/includes/TemplateParserTest.php
@@ -109,4 +109,17 @@ class TemplateParserTest extends MediaWikiTestCase {
                        ],
                ];
        }
+
+       public function testEnableRecursivePartials() {
+               $tp = new TemplateParser( $this->templateDir );
+               $data = [ 'r' => [ 'r' => [ 'r' => [] ] ] ];
+
+               $tp->enableRecursivePartials( true );
+               $this->assertEquals( 'rrr', $tp->processTemplate( 'recurse', $data ) );
+
+               $tp->enableRecursivePartials( false );
+               $this->setExpectedException( 'Exception' );
+               $tp->processTemplate( 'recurse', $data );
+       }
+
 }