Internal compiler classes always return a string (#918)

* Internal compiler classes always return a string (the internal has_code flag has been removed for simplicity)
* Add :string method signature to compile method everywhere.

TODO.txt

@@ -29,5 +29,4 @@
 
 ## Unrelated / other
 - review (and avoid) use of 'clone' keyword
-- compiler->has_code seems silly. Why not have proper return values?
 - what is 'user literal support', why are unit tests skipped?

changelog/918.md

@@ -0,0 +1 @@
+- Internal compiler classes always return a string (the internal has_code flag has been removed for simplicity) [#918](https://github.com/smarty-php/smarty/pull/918)

src/Compile/Base.php

@@ -226,8 +226,8 @@ protected function convertScope($scope): int {
 	 * @param Template $compiler  compiler object
 	 * @param array                                 $parameter array with compilation parameter
 	 *
-	 * @return bool|string compiled code or true if no code has been compiled
+	 * @return string compiled code as a string
 	 * @throws \Smarty\CompilerException
 	 */
-	abstract public function compile($args, Template $compiler, $parameter = array(), $tag = null, $function = null);
+	abstract public function compile($args, Template $compiler, $parameter = array(), $tag = null, $function = null): string;
 }

src/Compile/BlockCompiler.php

@@ -50,7 +50,8 @@ class BlockCompiler extends Base {
 	 * @throws CompilerException
 	 * @throws Exception
 	 */
-	public function compile($args, Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 
 		if (!isset($tag[5]) || substr($tag, -5) !== 'close') {
 			$output = $this->compileOpeningTag($compiler, $args, $tag, $function);
@@ -77,7 +78,6 @@ public function compileChild(\Smarty\Compiler\Template $compiler) {
 			);
 		}
 		$compiler->_cache['blockParams'][$compiler->_cache['blockNesting']]['callsChild'] = true;
-		$compiler->has_code = true;
 		$compiler->suppressNocacheProcessing = true;
 
 		$output = "<?php \n";
@@ -102,7 +102,6 @@ public function compileParent(\Smarty\Compiler\Template $compiler) {
 				$compiler->getParser()->lex->taglineno
 			);
 		}
-		$compiler->has_code = true;
 		$compiler->suppressNocacheProcessing = true;
 
 		$output = "<?php \n";

src/Compile/CompilerInterface.php

@@ -17,10 +17,10 @@ interface CompilerInterface {
 	 * @param \Smarty\Compiler\Template $compiler compiler object
 	 * @param array $parameter array with compilation parameter
 	 *
-	 * @return bool|string compiled code or true if no code has been compiled
+	 * @return string compiled code as a string
 	 * @throws \Smarty\CompilerException
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null);
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string;
 
 	public function isCacheable(): bool;
 }

src/Compile/DefaultHandlerFunctionCallCompiler.php

@@ -27,7 +27,8 @@ class DefaultHandlerFunctionCallCompiler extends Base {
 	 * @throws \Smarty\CompilerException
 	 * @throws \Smarty\Exception
 	 */
-	public function compile($args, Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		// check and get attributes
 		$_attr = $this->getAttributes($compiler, $args);
 		unset($_attr['nocache']);

src/Compile/FunctionCallCompiler.php

@@ -49,7 +49,8 @@ class FunctionCallCompiler extends Base {
 	 * @throws \Smarty\CompilerException
 	 * @throws \Smarty\Exception
 	 */
-	public function compile($args, Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 
 		// check and get attributes
 		$_attr = $this->getAttributes($compiler, $args);

src/Compile/ModifierCompiler.php

@@ -33,9 +33,8 @@ class ModifierCompiler extends Base {
 	 * @throws \Smarty\CompilerException
 	 * @throws \Smarty\Exception
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
-
-		$compiler->has_code = true;
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 
 		$output = $parameter['value'];
 

src/Compile/ObjectMethodCallCompiler.php

@@ -39,7 +39,8 @@ class ObjectMethodCallCompiler extends Base {
 	 * @throws \Smarty\CompilerException
 	 * @throws \Smarty\Exception
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		// check and get attributes
 		$_attr = $this->getAttributes($compiler, $args);
 		unset($_attr['nocache']);

src/Compile/PrintExpressionCompiler.php

@@ -47,9 +47,8 @@ class PrintExpressionCompiler extends Base {
 	 * @return string
 	 * @throws \Smarty\Exception
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
-
-		$compiler->has_code = true;
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 
 		// check and get attributes
 		$_attr = $this->getAttributes($compiler, $args);

src/Compile/SpecialVariableCompiler.php

@@ -37,9 +37,8 @@ class SpecialVariableCompiler extends Base {
 	 * @return string compiled code
 	 * @throws CompilerException
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
-
-		$compiler->has_code = true;
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 
 		$_index = preg_split("/\]\[/", substr($parameter, 1, strlen($parameter) - 2));
 		$variable = smarty_strtolower_ascii($compiler->getId($_index[0]));
@@ -129,5 +128,7 @@ public function compile($args, \Smarty\Compiler\Template $compiler, $parameter =
 			}
 			return $compiled_ref;
 		}
+
+		return '';
 	}
 }

src/Compile/Tag/Append.php

@@ -35,8 +35,8 @@ class Append extends Assign
      * @return string compiled code
      * @throws \Smarty\CompilerException
      */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = array(), $tag = null, $function = null)
-    {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = array(), $tag = null, $function = null): string
+	{
 
         // check and get attributes
         $_attr = $this->getAttributes($compiler, $args);

src/Compile/Tag/Assign.php

@@ -55,8 +55,8 @@ class Assign extends Base
      * @return string compiled code
      * @throws \Smarty\CompilerException
      */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = array(), $tag = null, $function = null)
-    {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = array(), $tag = null, $function = null): string
+	{
 
         $_nocache = false;
         // check and get attributes

src/Compile/Tag/BCPluginWrapper.php

@@ -24,7 +24,8 @@ public function __construct($callback, bool $cacheable = true) {
 	/**
 	 * @inheritDoc
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		return call_user_func($this->callback, $this->getAttributes($compiler, $args), $compiler->getSmarty());
 	}
 }

src/Compile/Tag/Block.php

@@ -58,7 +58,7 @@ class Block extends Inheritance {
 	 * @param \Smarty\Compiler\Template $compiler compiler object
 	 * @param array $parameter array with compilation parameter
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = array(), $tag = null, $function = null)
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = array(), $tag = null, $function = null): string
 	{
 		if (!isset($compiler->_cache['blockNesting'])) {
 			$compiler->_cache['blockNesting'] = 0;
@@ -87,5 +87,6 @@ public function compile($args, \Smarty\Compiler\Template $compiler, $parameter =
 		$compiler->getParser()->current_buffer = new Template();
 		$compiler->getTemplate()->getCompiled()->setNocacheCode(false);
 		$compiler->suppressNocacheProcessing = true;
+		return '';
 	}
 }

src/Compile/Tag/BlockClose.php

@@ -18,7 +18,7 @@ class BlockClose extends Inheritance {
 	 *
 	 * @return bool true
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = array(), $tag = null, $function = null)
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = array(), $tag = null, $function = null): string
 	{
 		[$_attr, $_nocache, $_buffer, $_has_nocache_code, $_className] = $this->closeTag($compiler, ['block']);
 
@@ -103,7 +103,6 @@ public function compile($args, \Smarty\Compiler\Template $compiler, $parameter =
 		if ($compiler->_cache['blockNesting'] === 0) {
 			unset($compiler->_cache['blockNesting']);
 		}
-		$compiler->has_code = true;
 		$compiler->suppressNocacheProcessing = true;
 		return $output;
 	}

src/Compile/Tag/BreakTag.php

@@ -52,7 +52,7 @@ class BreakTag extends Base {
 	 * @return string compiled code
 	 * @throws \Smarty\CompilerException
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = array(), $tag = null, $function = null)
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = array(), $tag = null, $function = null): string
 	{
 		[$levels, $foreachLevels] = $this->checkLevels($args, $compiler);
 		$output = "<?php ";

src/Compile/Tag/Call.php

@@ -47,7 +47,8 @@ class Call extends Base {
 	 *
 	 * @return string compiled code
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		// check and get attributes
 		$_attr = $this->getAttributes($compiler, $args);
 		// save possible attributes

src/Compile/Tag/Capture.php

@@ -53,7 +53,8 @@ public static function compileSpecialVariable(
 	 *
 	 * @return string compiled code
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		// check and get attributes
 		$_attr = $this->getAttributes($compiler, $args);
 		$buffer = $_attr['name'] ?? "'default'";
@@ -66,7 +67,6 @@ public function compile($args, \Smarty\Compiler\Template $compiler, $parameter =
 			$compiler->openTag('nocache');
 		}
 
-		$_output = "<?php \$_smarty_tpl->getSmarty()->getRuntime('Capture')->open(\$_smarty_tpl, $buffer, $assign, $append);?>";
-		return $_output;
+		return "<?php \$_smarty_tpl->getSmarty()->getRuntime('Capture')->open(\$_smarty_tpl, $buffer, $assign, $append);?>";
 	}
 }

src/Compile/Tag/CaptureClose.php

@@ -29,7 +29,8 @@ class CaptureClose extends Base {
 	 *
 	 * @return string compiled code
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 
 		if (array_pop($compiler->_cache['capture_stack'])) {
 			// pop the virtual {nocache} tag from the stack.

src/Compile/Tag/ConfigLoad.php

@@ -62,7 +62,8 @@ class ConfigLoad extends Base {
 	 * @return string compiled code
 	 * @throws \Smarty\CompilerException
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		// check and get attributes
 		$_attr = $this->getAttributes($compiler, $args);
 		if ($_attr['nocache'] === true) {

src/Compile/Tag/Debug.php

@@ -29,7 +29,8 @@ class Debug extends Base {
 	 *
 	 * @return string compiled code
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		// check and get attributes, may trigger errors
 		$this->getAttributes($compiler, $args);
 

src/Compile/Tag/ElseIfTag.php

@@ -22,7 +22,8 @@ class ElseIfTag extends Base {
 	 * @return string compiled code
 	 * @throws \Smarty\CompilerException
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 
 		[$nesting, $nocache_pushed] = $this->closeTag($compiler, ['if', 'elseif']);
 

src/Compile/Tag/ElseTag.php

@@ -20,7 +20,8 @@ class ElseTag extends Base {
 	 *
 	 * @return string compiled code
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		[$nesting, $compiler->tag_nocache] = $this->closeTag($compiler, ['if', 'elseif']);
 		$this->openTag($compiler, 'else', [$nesting, $compiler->tag_nocache]);
 		return '<?php } else { ?>';

src/Compile/Tag/EvalTag.php

@@ -52,7 +52,8 @@ class EvalTag extends Base {
 	 *
 	 * @return string compiled code
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		// check and get attributes
 		$_attr = $this->getAttributes($compiler, $args);
 		if (isset($_attr['assign'])) {

src/Compile/Tag/ExtendsTag.php

@@ -52,7 +52,8 @@ class ExtendsTag extends Inheritance {
 	 * @throws \Smarty\CompilerException
 	 * @throws \Smarty\Exception
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		// check and get attributes
 		$_attr = $this->getAttributes($compiler, $args);
 		if ($_attr['nocache'] === true) {
@@ -86,7 +87,6 @@ public function compile($args, \Smarty\Compiler\Template $compiler, $parameter =
 		} else {
 			$this->compileEndChild($compiler, $_attr['file']);
 		}
-		$compiler->has_code = false;
 		return '';
 	}
 

src/Compile/Tag/ForClose.php

@@ -29,7 +29,8 @@ class ForClose extends Base {
 	 *
 	 * @return string compiled code
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		$compiler->loopNesting--;
 
 		[$openTag, $nocache_pushed] = $this->closeTag($compiler, ['for', 'forelse']);

src/Compile/Tag/ForElse.php

@@ -21,7 +21,8 @@ class ForElse extends Base {
 	 *
 	 * @return string compiled code
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		[$tagName, $nocache_pushed] = $this->closeTag($compiler, ['for']);
 		$this->openTag($compiler, 'forelse', ['forelse', $nocache_pushed]);
 		return "<?php }} else { ?>";

src/Compile/Tag/ForTag.php

@@ -28,7 +28,8 @@ class ForTag extends Base {
 	 *
 	 * @return string compiled code
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		$compiler->loopNesting++;
 		if ($parameter === 0) {
 			$this->required_attributes = ['start', 'to'];

src/Compile/Tag/ForeachClose.php

@@ -29,7 +29,8 @@ class ForeachClose extends Base {
 	 * @return string compiled code
 	 * @throws \Smarty\CompilerException
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		$compiler->loopNesting--;
 
 		[$openTag, $nocache_pushed, $localVariablePrefix, $item, $restore] = $this->closeTag($compiler, ['foreach', 'foreachelse']);

src/Compile/Tag/ForeachElse.php

@@ -20,7 +20,8 @@ class ForeachElse extends Base {
 	 *
 	 * @return string compiled code
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 
 		[$openTag, $nocache_pushed, $localVariablePrefix, $item, $restore] = $this->closeTag($compiler, ['foreach']);
 		$this->openTag($compiler, 'foreachelse', ['foreachelse', $nocache_pushed, $localVariablePrefix, $item, false]);

src/Compile/Tag/ForeachTag.php

@@ -79,7 +79,8 @@ class ForeachTag extends ForeachSection {
 	 * @throws \Smarty\CompilerException
 	 * @throws \Smarty\Exception
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		$compiler->loopNesting++;
 		// init
 		$this->isNamed = false;

src/Compile/Tag/FunctionClose.php

@@ -33,9 +33,10 @@ class FunctionClose extends Base {
 	 * @param array $args array with attributes from parser
 	 * @param object|\Smarty\Compiler\Template $compiler compiler object
 	 *
-	 * @return bool true
+	 * @return string compiled code
 	 */
-	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null) {
+	public function compile($args, \Smarty\Compiler\Template $compiler, $parameter = [], $tag = null, $function = null): string
+	{
 		$this->compiler = $compiler;
 		$saved_data = $this->closeTag($compiler, ['function']);
 		$_attr = $saved_data[0];
@@ -140,7 +141,7 @@ public function compile($args, \Smarty\Compiler\Template $compiler, $parameter =
 		// restore old status
 		$compiler->getTemplate()->getCompiled()->setNocacheCode($saved_data[2]);
 		$compiler->getTemplate()->caching = $saved_data[3];
-		return true;
+		return '';
 	}
 
 	/**