[Lazarus] TBufDataset issues

[Michael Van Canneyt]

On Fri, 1 May 2020, Werner Pamler via lazarus wrote:

> Am 30.04.2020 um 10:45 schrieb Michael Van Canneyt via lazarus:
>> I added several menus:
>> - Create dataset (what you need)
>> - Save data to file (allows to save data in memory to file)
>> - Load data from file (allows to load data from a file into memory) - Copy 
>> data from another dataset (what it says on the tin :-))
> Thank you.
>
>>>> (2) Persistent fields: Wanting to create persistent fields at design time 
>>>> I do this: Make sure that the BufDataset is active. Right-click on the 
>>>> component to add the Fields Editor. I see the fields created. But how do 
>>>> I make them persistent? In Delphi I select both fields and click the '+'. 
>>>> Here the field list which opens is empty and the "Create" button is 
>>>> disabled. In other datasets everything is working correctly here, but 
>>>> TBufDataset seems to be incomplete.
>> Works fine here, be sure to set correct properties for the fields you add.
>> If any of the fields has incorrectly configured properties, it won't work.
>> 
>> But I did this when the dataset was not yet active. Maybe that is your
>> problem.
>
> Although I had it working some time after I had sent my mail I now have the 
> same issue again and I don't know why- see attached demo. I had entered two 
> field defs, clicked the new "CreateDataset" option (which automatically set 
> the Dataset to Active, however, not immediately, only after clicking 
> somewhere else).

You must do this when the dataset is NOT yet created.

I tried that and it works fine.

When the dataset is created, the fields editor shows the fields, as it
should. But they are not persistent. In order to make the fields persistent,
the dataset may not be empty.

Michael.