Simple autocomplete with Ace Editor in AS3? - actionscript-3

Question

I'm working in XML and I'd like to provide autocomplete suggestions for the attributes for specific node types using AS3.
For example, if the user is has a cursor in the following node:
<s:Button label="Hello World"/>
I'd like autocomplete to show "width, height, x, y".
I'm trying to get the node name and namespace and then give the editor a list of attributes that should appear in autocomplete.
I found similar questions but those are using a service call and a few that are out dated. I may delete this question if it is a duplicate.
Ace Editor for AS3 here.

Answer 1

In my case, for AS3, it is a combination of items:
ace.setCompleters(null); // I'm removing existing autocomplete
ace.addCompleter(codeCompleter); // adding my own
public var autoCompleteErrorMessage:String = "Nothing available";
public function codeCompleter(editor:Object, session:Object, position:Object, prefix:String, callback:Function):void {
var row:int = position.row;
var column:int = position.column;
/*
if (prefix.length === 0) {
callback(null, []);
return;
}
*/
//var myList:Array = {value: "message", caption: "Caption to user", meta: "Type shown", score: "I don't know"};
var testing:Boolean = false;
if (testing) {
callback(autoCompleteErrorMessage, [{value:"addedToStage"},{value:"added"},{value:"adding"}]);
}
else {
callback(autoCompleteErrorMessage, attributes);
}
}
protected function cursorChangeHandler(event:Event):void {
var qname:QName = getQNameFromCursorPosition(ace.row, ace.column);
if (qname==null) {
if (attributes.length) {
attributes = [];
}
return;
}
if (qname) {
attributes = getSuggestionListFromObject(classObject);
autoCompleteErrorMessage = null;
lastSelectedQName = qname;
}
}
public static var XML_TAG_NAME:String = "meta.tag.tag-name.xml";
public static var XML_TAG_OPEN:String = "meta.tag.punctuation.tag-open.xml";
public static var XML_TAG_CLOSE:String = "meta.tag.punctuation.tag-close.xml";
public static var XML_ATTRIBUTE_NAME:String = "entity.other.attribute-name.xml";
public function getQNameFromCursorPosition(row:int, column:int):QName {
var token:Object;
var line:String;
var type:String;
var value:String;
var found:Boolean;
var qname:QName;
for (; row > -1; row--) {
line = ace.getLine(row);
column = line.length;
for (; column>-1; column--) {
token = ace.getTokenAt(row, column);
type = token ? token.type : "";
if (type==XML_TAG_NAME) {
value = token.value;
found = true;
}
}
if (found) break;
}
if (found) {
qname = new QName("", value);
}
return qname;
}
The getQNameFromCursorPosition() method is fragile and I'm looking into a new method using the jumpToMatching() method.