ENH Do not show icon if binary is not available

src/Extensions/PdfExportExtension.php

@@ -6,6 +6,8 @@
 use SilverStripe\Control\Director;
 use SilverStripe\ORM\DataExtension;
 use SilverStripe\Versioned\Versioned;
+use SilverStripe\Dev\Deprecation;
+use SilverStripe\Core\Environment;
 
 class PdfExportExtension extends DataExtension
 {
@@ -68,6 +70,22 @@ public function PdfLink()
             return false;
         }
 
+        $binaryPath = $this->owner->config()->get('wkhtmltopdf_binary');
+        if ($binaryPath) {
+            Deprecation::notice('3.0', 'wkhtmltopdf_binary config is deprecated. '.
+                'Use WKHTMLTOPDF_BINARY env var instead.');
+        }
+        if (!$binaryPath || !is_executable($binaryPath ?? '')) {
+            if (Environment::getEnv('WKHTMLTOPDF_BINARY')
+                && is_executable(Environment::getEnv('WKHTMLTOPDF_BINARY') ?? '')
+            ) {
+                $binaryPath = Environment::getEnv('WKHTMLTOPDF_BINARY');
+            }
+        }
+        if (!$binaryPath) {
+            return false;
+        }
+
         $path = $this->getPdfFilename();
 
         if ((Versioned::get_stage() === Versioned::LIVE) && file_exists($path ?? '')) {