B4J Question How to updating chart via B4J?

[rbghongade]

Dear friends,
I am trying to create an application using B4J and Raspberry Pi 2 (a non-ui app). Raspberry Pi hosts the webpage (html). I want to update a line graph at timed intervals, but have no clue as to how to pass the value from B4J to html using jQuery. I am using RGraph as template for drawing line graph.
I am a complete novice as far as html and jQuery are concerned.
I was able to switch on/off an LED with a button on html page (client side) and also display a random value as text on the webpage.
Please let me know.
Regards,

 

[billzhan]

Ajax or websocket?

Ajax:
an Rgraph demo : http://www.rgraph.net/demos/basic-ajax-dynamic-updates.html
b4j server: a handler to feed the data

websocket:
ws.Runfunction with parameter(data), and some javascript is needed to update the line

 

[rbghongade]

Dear billzhan,
Thank you for the reply. I tried the websocket method but am not able to get anywhere. How do I pass the parameters? I do not now how to write java script . Ihave attached my test project. If you can spare some time please let me know as to where I am going wrong.

 

[billzhan]

Demo attached may help you.

 

[rbghongade]

Dear billzhan,
Just what I needed! Thanks a lot friend.

 

[rbghongade]

Dear billzhan,
With your help I am now able to add one more object to html page ! Thanks once again. My new problem is that the data acquisition( here emulated by a timer) is triggered ONLY when websocket is connected, whereas I want it to continue irrespective of any client connection. However it should display the same whenever client is connected. Is there a way to achieve the same? I have attached my project for your perusal.
Thanks in advance!

 

[billzhan]

Data is stored and retrieved in the main thread.
New client javascript is used to update the data for line graph.

Find the details in attached demo

 

[rbghongade]

Wow! That was great!