# Refreshing Properties Panel without applying pipeline object
**URL:** https://discourse.paraview.org/t/refreshing-properties-panel-without-applying-pipeline-object/17731
**Category:** Development
**Created:** [September 15, 2026, 5:41pm UTC](https://discourse.paraview.org/t/refreshing-properties-panel-without-applying-pipeline-object/17731 "2026-09-15T17:41:25Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Kenneth\_Moreland](https://discourse.paraview.org/u/Kenneth_Moreland)
#### Post date: [September 15, 2026, 5:41pm UTC](https://discourse.paraview.org/t/refreshing-properties-panel-without-applying-pipeline-object/17731/1 "2026-09-15T17:41:25Z")
I have a reader that reads data from two files: one holding a grid and one holding fields. The sequence for loading this data is to open the file with the grid and then select the file holding the fields using a selector in the Properties Panel GUI.
That all works fine except the GUI is supposed to also list all the fields to select which ones to load. The problem is that these array selection widgets need the fields file to populate them, but the fields file is not known until after the GUI is built and the widgets should be populated. After you hit **Apply** , the fields get refreshed with the proper information, but by then it is too late as the data is already loaded.
Is there a way to create a property in the panel that refreshes the panel when the value is changed?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [September 16, 2026, 6:52am UTC](https://discourse.paraview.org/t/refreshing-properties-panel-without-applying-pipeline-object/17731/2 "2026-09-16T06:52:46Z")
Yes, find the secondary file automatically in RequestInformation and parse it. It means the secondary file cannot be a user input, it has to be found automatically.
If thats not possible, you need to create a dedicated domain that will handle the parsing of the second file for you and add a button in the widget to update the list of fields after the second file has been selected, but its definitely harder to implement and more custom.
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### Author:  [@Kenneth\_Moreland](https://discourse.paraview.org/u/Kenneth_Moreland)
#### Post date: [September 16, 2026, 12:23pm UTC](https://discourse.paraview.org/t/refreshing-properties-panel-without-applying-pipeline-object/17731/3 "2026-09-16T12:23:43Z")
> [@mwestphal](#):
>
> Yes, find the secondary file automatically in RequestInformation and parse it. It means the secondary file cannot be a user input, it has to be found automatically.
That’s not possible in this case. There is no convention for naming the files, and they are often placed in separate directories.
> [@mwestphal](#):
>
> If thats not possible, you need to create a dedicated domain that will handle the parsing of the second file for you and add a button in the widget to update the list of fields after the second file has been selected, but its definitely harder to implement and more custom.
That sounds like I need to edit or subclass `vtkSMFileListDomain`. Is there a way to modify its `Update` method to rerun `RequestInformation` on the server side and refresh the GUI on the client?