usage with CKEditor

Download your CKEditor package

<script src="http://cdn.ckeditor.com/4.4.4/basic/ckeditor.js"></script>

Configure

var at_config = {
	at: "@",
	data: names,
	tpl: "<li data-value='@${name}'>${name} <small>${email}</small></li>"
}

// Bind to every CKEditor instance that'll load in the future
CKEDITOR.on('instanceReady', function(event) {
		
	var editor = event.editor;
	
	// Make sure the textarea's `contentEditable` property is set to `true`
	editor.document.getBody().$.contentEditable = true;
		
	// Switching from and to source mode
	editor.on('mode', function(e) {
		load_atwho(this);
	});
	
	// First load
	load_atwho(editor);
		
});

function load_atwho(editor, at_config) {
	
	// WYSIWYG mode when switching from source mode
	if (editor.mode != 'source') {

    	editor.document.getBody().$.contentEditable = true;
    	
		$(editor.document.getBody().$)
			.atwho('setIframe', editor.window.getFrame().$)
			.atwho(at_config);
			
	}
	// Source mode when switching from WYSIWYG
	else {
		$(editor.container.$).find(".cke_source").atwho(at_config);
	}
	
}

Prevent adding a new line when pressing ENTER

var ckeditor = $('#yourSelector').ckeditor({...}).ckeditorGet();
ckeditor.enableEnter = true; //Use this as a flag

ckeditor.on('instanceReady',function(event) {
    var at_config = {...};

   this.document.getBody().$.contentEditable = true;
    $(this.document.getBody().$).atwho(at_config);
    $(this.document.getBody().$).on('shown.atwho', function(event){
        ckeditor.enableEnter = false;
    });
    $(this.document.getBody().$).on('hidden.atwho', function(event){
        setTimeout(function(){
            //console.log("hide! setting to TRUE");
            ckeditor.enableEnter = true;
        },100); //Give it a small time so that the ENTER key only affects the popup and not the editor
    });
});

ckeditor.on( 'key', function( event ) {
    if ( event.data.keyCode == 13 && !ckeditor.enableEnter ) {
        event.cancel();
    }
});