beforeUpdate Error when using dynamic content (#25)

Author: mbazzo

dist/vue-code-highlight.min.js

@@ -788,9 +788,11 @@ var vueCodeHighlight = (function (exports) {
 	  },
 
 	  beforeUpdate: function beforeUpdate() {
-	    var newText = this.$slots.default[0].text.replace(/^[\r\n\s]*|[\r\n\s]*$/g, '');
-	    this.$el.querySelector('code').textContent = newText;
-	    Prism.highlightAllUnder(this.$refs.codeBlock);
+      if(this.$slots.default[0].text){
+	      var newText = this.$slots.default[0].text.replace(/^[\r\n\s]*|[\r\n\s]*$/g, '');
+	      this.$el.querySelector('code').textContent = newText;
+	      Prism.highlightAllUnder(this.$refs.codeBlock);
+      }
 	  },
 	};