Custom auto-completer of ace editor

I have a custom node using editor javascript. I want to customize the auto-completer in my node.
I modify as below:

this.editor = function (id, value, defaultValue) {
 mode: "ace/mode/javascript",

I run well in my node. But one big problem is that the completer in the node [function] editor was changed. How can the custom completer work in my node scope only?