diff --git a/html_resources/code-block/code-block.js b/html_resources/code-block/code-block.js
index 73c3095..3cf0f74 100644
--- a/html_resources/code-block/code-block.js
+++ b/html_resources/code-block/code-block.js
@@ -21,7 +21,11 @@ class CodeBlock extends HTMLElement{
   }
   
   determineAndLoadContent(){
-    CodeBlock.getSource(this.src)
+    const src = this.src;
+    if(!src){
+      return
+    }
+    CodeBlock.getSource(src)
     .then(
       (data) => this.consumeData(data,CodeBlock.InsertMode.Replace),
       (e) => this.consumeData({content:this.textContent},CodeBlock.InsertMode.Replace)
@@ -313,7 +317,10 @@ class CodeBlock extends HTMLElement{
   }
   
   get codeBox(){
-    return this.shadowRoot.querySelector("tbody");
+    if(!this._codeBox){
+      this._codeBox = this.shadowRoot.querySelector("tbody");
+    }
+    return this._codeBox;
   }
   get value(){
     return this.codeBox.textContent