[Not a bug] Configuration 'use_function' called for display instead of update

Background
For some configuration options (for a plugin), I would like to call a function when the value is "updated" and only when the value is "updated". I'd like to use the built-in configuration system if possible for these options. While working with the field I noted a discrepancy between the wiki documentation and the code in configuration.php. So a "bug" of sorts in one place or the other.

Question
From the wiki documentation the function listed in the 'use_function' column is run on input by the user before changing 'configuration_value'. Based upon this I would expect the function to only be called when the "update" button is clicked. Is this the expected behavior (or outdated documentation)?

Looking at 'admin/configuration.php' this file runs the 'use_function' before displaying any configuration options / values instead of when a value is updated. Is this a bug or intended behavior?

Hi,

It is the wiki information that is incorrect. The use_function is used to transform a configuration value before displaying it.

e.g. the configuration value may be a country id, this needs to be transformed to a countries name before displaying.

I have updated the wiki to reflect this.

Thank You for the clarification :smile: