Feature request #21337
Graphical Builder - Link between Expression Paramenter and Table/Vector Field
| Status: | Open | ||
|---|---|---|---|
| Priority: | Normal | ||
| Assignee: | - | ||
| Category: | Processing/Modeller | ||
| Pull Request or Patch supplied: | No | Resolution: | |
| Easy fix?: | No | Copied to github as #: | 29155 |
Description
Hello folks,
I have a feature request:It would be nice to implement a link between the input parameter 'expression' and 'table/vector field' so it is useable for a dynamic workflow with a parameter like '@field_namen' inside of a expression. I have tried this in the field calculator, it is working only for the column name but the field values go in the 'null-nirvana'.
Thanks and best regards, Hape
History
#1
Updated by Alexis Roy-L over 5 years ago
Hans-Peter Klossek wrote:
Hello folks,
I have a feature request:
It would be nice to implement a link between the input parameter 'expression' and 'table/vector field' so it is useable for a dynamic workflow with a parameter like '@field_namen' inside of a expression. I have tried this in the field calculator, it is working only for the column name but the field values go in the 'null-nirvana'.
Thanks and best regards, Hape
Just out of curiosity, what is the intended use case of this?
One thing that is doable is to use the select by attribute and split the workflow in two.
Since this would be done on the feature scale I'm not too sure what the gain would be.
#2
Updated by Nyall Dawson over 5 years ago
You can use the existing "attribute" function, eg
attribute($currentfeature, @fieldparametername)