diff --git a/core/basepage.php b/core/basepage.php
index 61530187..f8827ae9 100644
--- a/core/basepage.php
+++ b/core/basepage.php
@@ -7,6 +7,7 @@ abstract class PageMode
     const DATA = 'data';
     const PAGE = 'page';
     const FILE = 'file';
+    const MANUAL = 'manual';
 }
 
 /**
@@ -238,16 +239,13 @@ class BasePage
 
     // ==============================================
 
-    /**
-     * Display the page according to the mode and data given.
-     */
-    public function display(): void
+    public function send_headers(): void
     {
-        header("HTTP/1.0 {$this->code} Shimmie");
-        header("Content-type: " . $this->type);
-        header("X-Powered-By: Shimmie-" . VERSION);
-
         if (!headers_sent()) {
+            header("HTTP/1.0 {$this->code} Shimmie");
+            header("Content-type: " . $this->type);
+            header("X-Powered-By: Shimmie-" . VERSION);
+
             foreach ($this->http_headers as $head) {
                 header($head);
             }
@@ -257,8 +255,25 @@ class BasePage
         } else {
             print "Error: Headers have already been sent to the client.";
         }
+    }
+
+    public function flush_output(): void
+    {
+
+    }
+
+    /**
+     * Display the page according to the mode and data given.
+     */
+    public function display(): void
+    {
+        if($this->mode!=PageMode::MANUAL) {
+            $this->send_headers();
+        }
 
         switch ($this->mode) {
+            case PageMode::MANUAL:
+                break;
             case PageMode::PAGE:
                 usort($this->blocks, "blockcmp");
                 $this->add_auto_html_headers();
diff --git a/core/polyfills.php b/core/polyfills.php
index 8a54ac2d..0b733987 100644
--- a/core/polyfills.php
+++ b/core/polyfills.php
@@ -150,6 +150,14 @@ function list_files(string $base, string $_sub_dir=""): array
     return $file_list;
 }
 
+function flush_output(): void
+{
+    if (!defined("UNITTEST")) {
+        @ob_flush();
+    }
+    flush();
+}
+
 function stream_file(string $file, int $start, int $end): void
 {
     $fp = fopen($file, 'r');
@@ -162,10 +170,7 @@ function stream_file(string $file, int $start, int $end): void
                 $buffer = $end - $p + 1;
             }
             echo fread($fp, $buffer);
-            if (!defined("UNITTEST")) {
-                @ob_flush();
-            }
-            flush();
+            flush_output();
 
             // After flush, we can tell if the client browser has disconnected.
             // This means we can start sending a large file, and if we detect they disappeared