Implement template execution error handling

Closes #16.
dlang-dockerized · Jul 29, 2024 · aa7be9b · aa7be9b
1 parent 53f4c20
commit aa7be9b
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Showing 2 changed files with 56 additions and 4 deletions.
diff --git a/tools/ddct-src/Util/TemplateEngine.php b/tools/ddct-src/Util/TemplateEngine.php
@@ -18,15 +18,18 @@ final class TemplateEngine
     private const phpPrintTag = '<?= ';
     private const phpCloseTagLF = " ?>\n\n";
     private const phpCloseTag = " ?>\n";
-    private const phpIncludeOpenTag = '<?php eval($_te->getCompiledTemplate(\'';
-    private const phpIncludeCloseTag = '\'))?>';
+    private const phpIncludeOpenTag = '<?php $_eh->push(\'';
+    private const phpIncludeMiddle = '\');eval($_te->getCompiledTemplate(\'';
+    private const phpIncludeCloseTag = '\'));$_eh->pop()?>';
     private const tab = "\t";
 
     private array $cache = [];
+    private TemplateExecutionErrorHandlers $errorHandlers;
 
     public function __construct(
         private string $templatesDir,
     ) {
+        $this->errorHandlers = new TemplateExecutionErrorHandlers();
     }
 
     public function compile(string $templateName): void
@@ -104,6 +107,8 @@ public function compile(string $templateName): void
                 $line = substr($line, 4, ($lineLength - 8));
                 unset($lineLength);
                 $result .= $line;
+                $result .= self::phpIncludeMiddle;
+                $result .= $line;
                 $result .= self::phpIncludeCloseTag;
                 continue;
             }
@@ -131,7 +136,7 @@ public function compileIfNotInCache(string $templateName): void
         // Shall write compiled template to file?
         if (isset($_SERVER['TPL_DEBUG']) && ($_SERVER['TPL_DEBUG'] === 'file')) {
             file_put_contents(
-                $this->makeTemplatePath($templateName) . '.compiled-tpl.php',
+                $this->makeTemplatePath($templateName) . TemplateExecutionErrorHandlers::fileEndingCompiledTemplate,
                 $this->cache[$templateName]
             );
         }
@@ -173,16 +178,22 @@ public function execute(string $templateName, array $variables): void
 
     private function executeTemplate(string $templateName, array $variables)
     {
-        (function (TemplateEngine $_te, string $_tplCode, array $_variables) {
+        $this->errorHandlers->push($templateName);
+
+        (function (TemplateEngine $_te, TemplateExecutionErrorHandlers $_eh, string $_tplCode, array $_variables) {
             foreach ($_variables as $_name => $_value) {
                 $$_name = $_value;
             }
             eval($_tplCode);
         })(
             $this,
+            $this->errorHandlers,
             $this->cache[$templateName],
             $variables,
         );
+
+        $this->errorHandlers->pop();
+        $this->errorHandlers->resetAndCheck();
     }
 
     private function makeTemplatePath(string $templateName): string

diff --git a/tools/ddct-src/Util/TemplateExecutionErrorHandlers.php b/tools/ddct-src/Util/TemplateExecutionErrorHandlers.php
@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DlangDockerized\Ddct\Util;
+
+use Exception;
+use LogicException;
+
+final class TemplateExecutionErrorHandlers
+{
+    public const fileEndingCompiledTemplate = '.compiled-tpl.php';
+
+    private int $counter = 0;
+
+    public function push(string $templateName): void
+    {
+        $fileEnding = self::fileEndingCompiledTemplate;
+        set_error_handler(function ($errno, $errstr, $errfile, $errline) use ($templateName, $fileEnding) {
+            throw new Exception(
+                "Template execution error (code: {$errno})"
+                . " in `{$templateName}{$fileEnding}`({$errline}): {$errstr}"
+            );
+        }, E_ALL);
+
+        ++$this->counter;
+    }
+
+    public function pop(): void
+    {
+        restore_error_handler();
+        --$this->counter;
+    }
+
+    public function resetAndCheck(): void
+    {
+        if ($this->counter !== 0) {
+            throw new LogicException('Popped less error handlers than pushed.');
+        }
+    }
+}