How to find out if the dynamic list is not empty?

And one more question: how can I find out if the DynamicList contain any data?
The task is to suggest adding a first item to the empty list. It has some filters so checking if my catalog is empty is not the thing which will help here.

I think you have to:
1. Read all filters which have "use = true"
2. Write a query to this object (whith all filters from 1)

:( It is a complicated query so I would not like to repeat it due to it's hard to support. If there is a way to use the one which is built in into the DynamicList? Or maybe there is a simpler way? How can I understand if there is any item displayed in the form item having this DynamicList as a data source?

Try to check if the CurrentRow is Undefined for your list the DynamicList is empty.

#4 Not working because When You change filter and list was empty befor and filled after changing filter you'll have CurrentRow is Undefined  but there is data in list. I think Silvia need something like

   QueryBuilder = New QueryBuilder;
   BuilderText =  "SELECT
               |   Order.Ref
               |FROM
               |   Document.Order AS Order";
   QueryBuilder.Text = BuilderText;
   DataSourceDescription = New DataSourceDescription(DocListControl);
   QueryBuilder.DataSource = DataSourceDescription;
   
   QueryBuilder.Execute();
   TZ = QueryBuilder.Result.Unload();
   If TZ.Count() > 0 Then
      //not empty
   Else
      //empty
   EndIf;

Silvia Ashley, good question!
The fact that the filling DynamicList may influence the selection of previously established Programming. On the other hand - I never will have to solve such problems, but just can not come across ...
Figure 1:
Perform as suggested earlier request but we do not need to perform the entire query, not just run " Select * ..." but "Select FIRST 1 * ...."
Figure 2:
forcibly reset selections if they are installed, check for emptiness, "Items.List.CurrentRow" and then restore the selection if it was set.

Thank you guys!
Escander, the Figure 2 looks like what I need, could you please explain it? I can't get how to reset selections and why CurrentRow will work in that case, while Anatoly says it will not work after DynamicList filters changes.

Thank you, Anatoly, but to use this method I will have to synchronize the query in the DynamicList and in this additional query. Which I wouldn't like to do... If possible.

Silvia Ashley, tomorrow will try to distribute the sample (already too late).

In the general course in the morning immediately evident that the optimal solution is unique!
Use the query - this is optimal, but more often to check it does not reach.
The code below for a list form catalog customers.

&AtServerNoContext
Function TestOnServer()
   Query = New Query;
   Query.Text = 
      "SELECT TOP 1
      |   Catalog.Ref
      |FROM
      |   Catalog.Контрагенты AS Catalog";
 = Query.Execute();
Return  Result.IsEmpty();
EndFunction



&AtClient
Function ListEmpty()
   ii=True;
   If Lists.Filter.Items.Count()=0 Then
      If ValueIsFilled(Items.List.CurrentRow) Then
         ii=False;
      EndIf;   
   Else   
      If ValueIsFilled(Items.List.CurrentRow) Then
         ii=False;
      Else
         ii=TestOnServer();
      EndIf;   
   EndIf;
Return ii;   
EndFunction


&AtClient
Procedure OnOpen(Cancel)
   ff=ListEmpty();
EndProcedure

Forum engine eats up the code formatting - it looks ugly of course, not that the configuration tool

If someone knows how to get a query which is stored in the DynamicList settings?

Not always DynamicList based on a query can be used and a dynamic read and fill DynamicList with data having no connection to the dat abase(meaning a programmatic).
Get text queries will be a function:

&AtServer
Function QueryFromFormOnServer()
TxtQ="":
If List.CustomQuery Then
  TxtQ=List.QueryText:
EndIf
Return TxtQ;
EndFunction

Thank you, Escander! That is what I need: both getting the query text and adding filters to it do solve my problem.

Glad I could help you