Add some Events which fire BEFORE a Project Config change is applied.

[lindseydiloreto]

As far as I can tell, all of these existing Events get fired after a Project Config change has been applied...

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99% of the time, I'm sure those Events are sufficient. But I'm stuck in the 1% where a BEFORE Event would likely save the day.

I am converting one fieldtype into another using the existing ProjectConfig::EVENT_UPDATE_ITEM event.

• Fieldtype A has a column in the native Craft content table.
• Fieldtype B does not (the data is in a separate table).

When switching from Fieldtype A to Fieldtype B, the content column is deleted before I can access the old data.

I believe that a new event (ie: ProjectConfig::EVENT_BEFORE_UPDATE_ITEM) would give me the access I need to get the existing field data out of the content column before the column is deleted by the Project Config.

Hope that makes sense, let me know if you need me to clarify anything!

[brandonkelly]

You could use the craft\services\Fields::EVENT_BEFORE_SAVE_FIELD event, and re-fetch the field from the event handler, and compare them to see if the field type changed.

[lindseydiloreto]

Interesting. Would that also kick in when Project Config is applying the changes in a Production environment?

[lindseydiloreto]

I just ran a quick test, and it doesn't look like craft project-config/apply ever hits that event.

[lindseydiloreto]

FWIW, I tested both of these Events, and neither was pinged by craft up or craft project-config/apply...

use craft\base\Field;
use craft\services\Fields;

Event::on(
    Fields::class,
    Fields::EVENT_BEFORE_SAVE_FIELD,
    function (FieldEvent $event) {
        Craft::dd('Fields::EVENT_BEFORE_SAVE_FIELD');
    }
);

Event::on(
    Field::class,
    Field::EVENT_BEFORE_SAVE,
    function (ModelEvent $event) {
        Craft::dd('Field::EVENT_BEFORE_SAVE');
    }
);

[khalwat]

Yeah it looks like Project Config essentially maps YAML files to database tables, and isn't calling the Craft services that you might expect it would be when dealing with various data structures.

[brandonkelly]

Just added a new EVENT_BEFORE_APPLY_FIELD_SAVE event to craft\services\Fields for Craft 4.13 and 5.5, which will fire before any incoming project config changes have been applied. The incoming Project Config change will be accessible via $event->config.

[lindseydiloreto]

Brilliant, thanks @brandonkelly! 👏

I'll take it for a spin and let you know how it goes.

[brandonkelly]

Craft 4.13.0 and 5.5.0 are out now with that new event 🎉

[lindseydiloreto]

Amazing, thanks again @brandonkelly! 🍺