Accessing the individual fields within a field group

Hello there!

I need to access the individual fields in a field group. In comprofiler table I see each field in the group is set to null, and the field group field has some kind of two-dimensional array.

My scenario; I have a group of students I want to book sessions with. The field group cb_sessions, contains fields: cb_student, cb_sessiondate, cb_sessionstart, cb_sessionend and cb_attended. I would like to trigger an action on the update of this field, cb_sessions, and send an email to the student using auto actions. I look at the fields for triggering and see only the nullified fields. Any suggestions would be helpful...

I would also like to filter out students in this field group, when using a userlist, so that students can only see their sessions that I have booked. Not every student's session.

Your help would be appreciated, again!
Thanks
Tim

Field groups are stored in JSON columns as a JSON string. You can't apply normal field logic to them. So they have to be accessed in a different way and often you are not going to be able to filter on them like you would other fields. It is possible to search field group fields but you need to be using MySQL 5.7.8+ (MariaDB is not supported). If you have MySQL 5.7.8+ then you should be able to just mark the field as searchable like you would any other field.

As for accessing sub values inside of a field group field the substitutions for that are a bit tricky. Their format is as follows.

FIELD_NAME__INDEX__FIELD_NAME

The first field name is the name of your field group field. For example lets call it cb_fieldgroup. Next the index is the row in the field group field you want to access. The index always begins with 0. Finally the last field name is the name of the field in the field group field of the specified row that you want to substitute in. For example lets call this cb_text. This gives you the below.

cb_fieldgroup__0__cb_text

Used as a raw substitution you'd have the below.

[cb_fieldgroup__0__cb_text]

This should function anywhere substitutions are supported.

Great thanks! Fully understood! Substitutions work fine!

But, how would I specify the index of the last item in the JSON string?

But, how would I specify the index of the last item in the JSON string?

You would have to know what the last index is, but that does give me an idea to possibly implement another pseudo field for that. So you could do something like cb_fieldgroup__first__cb_text or cb_fieldgroup__last__cb_text. Have added a feature ticket for this.

forge.joomlapolis.com/issues/7873

Hmm...wouldn't first always be index 0? Last would always be length - 1?

A change would be good, but I'm actually looking at stripping the JSON string, parsing it, and putting the individual fields into their own table. It's a bit of a nightmare...

Yes, first is always 0. Last is not -1. Last is whatever the last row is. It increments up from 0. So if they've 10 rows the last row is index 9. All you're doing is accessing the array index of the stored JSON. Providing keywords for first, last, and maybe a few others is easier for users to use.

A change would be good, but I'm actually looking at stripping the JSON string, parsing it, and putting the individual fields into their own table. It's a bit of a nightmare...

Why? What purpose would there be to doing that?