Grails sImple chat - Chat messages not displaying on screen - grails

Question

Following is a code fragment obtained from Grails website.
<script>
function messageKeyPress(field,event) {
var theCode = event.keyCode ? event.keyCode : event.which ? event.which : event.charCode;
var message = $('#messageBox').val();
if (theCode == 13){
<g:remoteFunction action="submitMessage" params="\'message=\'+message" update="temp"/>
$('#messageBox').val('');
return false;
} else {
return true;
}
}
function retrieveLatestMessages() {
<g:remoteFunction action="retrieveLatestMessages" update="chatMessages"/>
}
function pollMessages() {
retrieveLatestMessages();
setTimeout('pollMessages()', 5000);
}
pollMessages();
</script>
The above code worked but when i added the Controller it stopped working. I meant that the records gets saved in the DB, but i am not able to retrieve the data and display on screen.
This is what i did
<g:remoteFunction controller="message" action="retrieveLatestMessages" update="chatMessages"/>
The MessageController function is as follows:
#Secured([ 'ROLE_USER'])
def retrieveLatestMessages() {
println "test"
def messages = Message.listOrderByDate(order: 'desc', max:1000)
[messages:messages.reverse()]
println messages
}
The above controller function gets executed (I see the println statements on console), but the data isn't getting populating on the screen.
Can someone help me out here
UPDATE
[{"class":"myPro.Message","id":3,"date":"2014-07-23T17:31:58Z","message":"dfdf","name":"hi"},{"class":"myPro.Message","id":2,"date":"2014-07-23T17:31:56Z","message":"dfdfdf","name":"dd"},{"class":"myPro.Message","id":1,"date":"2014-07-23T17:31:18Z","message":"xxxx","name":"fie"}]

Answer 1

Your method - retrieveLatestMessages() action in your case - must return a model, but it returns the output of println instead.
To make your code work, you must place the model in the last line, or explicitly return it by using return statement:
def retrieveLatestMessages() {
println "test"
def messages = Message.listOrderByDate(order: 'desc', max:1000)
println messages
[messages:messages.reverse()]
}

Answer 2

Try this
import grails.converters.JSON
#Secured([ 'ROLE_USER'])
def retrieveLatestMessages() {
println "test"
def messages = Message.listOrderByDate(order: 'asc', max:1000)
render messages as JSON
}
Enjoy.

Answer 3

I had this sample app working on mine with no issues but here is the thing, this process requires you to poll the page consistently and it is resource intensive:
I ended up writing a domainClass that was bound to a Datasource that was using the HQL db and was outside of my own app, the process requires a DB table to stream chat....
Alternative is to move away from polling and use websockets:
check out this video
https://www.youtube.com/watch?v=8QBdUcFqRkU
Then check out this video
https://www.youtube.com/watch?v=BikL52HYaZg
Finally look at this :
https://github.com/vahidhedayati/grails-websocket-example
This has been updated and includes the 2nd method of using winsocket to make simple chat ....