I need to assign custom ids for all users. The Id will come from API and its depend on other filled by user custom field. Witch hook should I use and witch variable holds id value?
2 Answers
I presume you're referring to a login ID - you should be able to use hook_form_alter to access the registration form, and create a default value.
get Devel module and use dpm($form) in that function to look through the array to find the exact element you want to change.
after that you can probably use a number of options to hide the element, including css so that the user can't change it before being submitted.
Are you looking to add a secondary ID field, separate from UID? If so, the user entity is fieldable, and you could probably use hook_user_update or hook_user_presave to populate the field, using aggregated the data from other user fields.
If I follow you correctly, it would be something like 'field_1 + field_2' comprise the new "ID" field you're creating. In which case, one of these hooks will achieve what you're looking for. Feel free to provide further clarification if needed.
