About building parametric objects with GDL.

Read list schemes data from gdl object

Alfredo Gzz

Hi, I’ve had a lot of time struggling searching for a way to read the data of a text list into a gdl object to output that info into a table like a schedule with more complex data and format that schedules can’t do.


I’ve spend a lot of time trying with gdl data I/O writing the source object data to a external file and reading that data into another gdl object but can’t delete the outputted record if the object is deleted, so cant update the file.


I see that the easiest way is to extract data from a list with a read txt or data addon or a simple request.

the only posible solution is to export the list data and then read it from the gdl object but I don’t think we have to get through al that process being the data I want just right there.


feels like is a very simple task but can’t find the way, I’ll appreciate your help.



Steve Jepson

Expressions ? 

Functions in Expressions | User Guide Page | GRAPHISOFT Help Center



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Peter Baksa

If your source data is one object only, do it with a label.

Péter Baksa
Software Engineer, Library as a Platform
Graphisoft SE, Budapest

Hi Steve, thank for your response but I think I know how to use expressions (I’m still a nobie) and can’t find the solution there, I think there’s got to be a request or I/o solution for this.


Thank you Peter, but no, my data source comes from multiple objects with property scripts in each of them to output data to a single list for merging all like in a schedule.

Now I just need my new gdl object to read that list to create a “schedule” object.


Sorry for my misunderstanding, regards!

Peter Baksa

It is not possible to collect data about all GDL objects from GDL, only an add-on can do that.

You could also try to set up a graphical list, but it is not easy. There should be a PDF about listing in the installed Archicad folder under Documentation.

Péter Baksa
Software Engineer, Library as a Platform
Graphisoft SE, Budapest


I use the following scheme - read information from an object with the COMPONENT command, displaying information using Lists/Components and saving the resulting text document. Further reading is done with standard GDL Text I / O Add-On functions

Structural engineer, developer of free addon for sync GDL param and properties


Thanks Peter that’s all I wanted to know.

I already do it with I/o addons but it’s very rare that we have to export the data (out of ac) and then read from that (in to ac) again even knowing the data is inside ac, this causes a non updated data if we change something in ac.

Hope we get this improve in next versions.



Yep, that the way I do it, it’s just that it’ll be better to have a better alternative for reading from data inside ac without having to export and read from external file since this is not updatable if an object is changed.

Also tried writing directly to an external txt file and reading at same time but can’t have the ability to update data because if you delete objects it doesn’t in the txt file.

Hopefully there’s a read or request data from a list solution further or an automatically deletion from db if an object is deleted in ac.


Thanks for the help, regards!

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