Results 1 to 5 of 5
  1. #1

    Angry Subscribing to item with invalid (non-existant) field breaks lightstreamer?

    Hi all,

    I'm using JavaScript / HTML as the client, with a Java Lightstreamer adapter serving the data.

    The problem I am encountering is that whenever I attempt to subscribe to an item, and specify a field on that item that doesn't exist, subsequent subscriptions all seem to fail silently. How do I know they're failing? Because my subscription listener returns null for every fieldValue that is returned. It does this once, after the subscription is made, and then never again does that listener receive data updates despite the item changing!

    I am wondering a basic question:

    Does attempting to create a Subscription with invalid fields, break lightstreamer? By invalid fields, I mean fields that do not exist on the item.

    Any help would be great!

  2. #2
    BUMP with more information:

    From the lightstreamer logs, I see the following when the data adapter updates the item:

    10-Jan-15 13:35:55,836|DEBUG|LightstreamerLogger.subscriptio ns|Thread-25 |Ignored late update for item item1

    What the hell is a 'late update'? I see no documentation about this.

  3. #3
    Please help!

    Why can I not unsubscribe from an item, reset the fields of the subscription, and then re-subscribe? All I get after re-subscribing is

    "Ignored late update for item item1"

    The abstracted workflow looks like this:

    lightstreamerClient.subscribe( item1Subscription );
    ... do some stuff on the page ...
    lightstreamerClient.unsubscribe( item1Subscription );
    ... do some more stuff on the page ...
    item1Subscription.setFields( newFields );
    lightstreamerClient.subscribe( item1Subscription );

  4. #4
    Figured the issue out.

    When a client unsubscribes, and then re-subscribes, you should be updating the _itemHandle in the Java adapter to use the new _itemHandle.

  5. #5
    Administrator
    Join Date
    Jul 2006
    Location
    Milan
    Posts
    975
    Correct.

    About fields, the fields specified in a subscription are free from constraints.
    A subscribed field that is never included in any update event for the item by the Data Adapter will just carry a null value in the snapshot and will be reported as unchanged in all updates.

 

 

Similar Threads

  1. HTTPS connection - Invalid Certificate Chain
    By doraintech in forum General
    Replies: 18
    Last Post: April 18th, 2014, 12:58 PM
  2. Getting "Invalid URI..."
    By SaravananB in forum Client APIs
    Replies: 1
    Last Post: April 11th, 2012, 09:52 AM
  3. BlackBerry error "Invalid Url Parameter"
    By JBBUSER in forum Client APIs
    Replies: 1
    Last Post: March 24th, 2011, 11:49 AM
  4. Replies: 2
    Last Post: December 24th, 2010, 08:51 AM
  5. Item vs Field
    By nickponico in forum General
    Replies: 1
    Last Post: March 1st, 2010, 10:38 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
All times are GMT +1. The time now is 08:26 AM.