List Update Not Working Through Event Trigger

I have the following situation. I hope the description helps:

  1. WebBlock 1 triggers an event and sends a structure record to a parent WebBlock (WebBlock 2).
  2. WebBlock 2 quickly (and only) triggers an event and sends the record from WebBlock 1 to the parent Page.
  3. The Page then handles the trigger from WebBlock 2 by appending the record (the one from WebBlock 1) to a local variable that is a record list.

When #3 happens a second or third time (there are many WebBlock 1s that trigger the same event in WebBlock 2) the record list on the Page looses data. Its records are somehow lost or their data gets erased. What am I missing here? There are no Submit actions that refresh the Page; there also aren't any Ajax Refresh. Again, WB 1 sends info to WB 2, then WB 2 sends that info to the Page. The Page then updates a local list (or tries to). That's all.

I am currently unable to upload the application here. Any help with the current description is very much appreciated. 

Hello Juan, 

Please, create a new module that reproduces the problem, using dummy structures and data, so you can attach it here and we can take a look. 


Hi Juan,

i tried to reproduce what you are doing, see attached oml, is this comparable to your plan ?

I have no problems building the list, both when webblock 1 is immediately on the screen and when webblock 1 is part of webblock 2 .

Can you verify what it is that you are doing different ?


Dorine Boudry wrote:


I have no problems building the list, both when webblock 1 is immediately on the screen and when webblock 1 is part of webblock 2 .

That's why it's very important for the person with the problem to show its code, or if not possible, to create a test module that reproduces the problem so it can attach it here, instead of being us to build a test to see what is happening. 

It is something that saves time for us that are answering, allowing us to help more people and providing solutions faster. 


Hi Eduardo,

I absolutely agree with you,

the more info the poster provides, the easier and quicker we can help.  Even just the exercise of creating a demo app reproducing their problem, might actually allow them to spot the problem themselves before even having to post  a question.

But for me, right now, I'm a new user of Outsystems, and looking for real world problems to solve in addition to the exercises that come with the online courses.  Every problem posted here creates an opportunity to learn something new.  For example, I hadn't done anything yet with passing back info from webblocks over several levels, so this post was my queue to try it out.