How to get group_id of a Channel entry's author?

Question

I need to implement some business rules based on the following:

1. The current user's {group_id}
2. The group id of the author of a particular Channel entry

I need to implement this rule within the {exp:channel:entries}, I suppose. In that loop, I'll have access to {author_id}, which possibly could be used somehow to get it's associated group id???

Answer 1

Documentation is a good place to start:

http://ellislab.com/expressionengine/user-guide/templates/globals/single_variables.html

http://ellislab.com/expressionengine/user-guide/modules/member/index.html#custom-profile-data-tag

{member_group} or {group_id}
{member_id}

also (if in channel:entries tag pair and don't want conflict):

{logged_in_member_id}
{logged_in_group_id}

Entry Authors details:

{exp:channel:entries}
    {author_id} or {member_id} will be the same inside entries loop
    {group_id} will be authors group inside entries loop
{/exp:channel:entries}

Get custom member details:

{exp:member:custom_profile_data member_id="?????"}
{/exp:member:custom_profile_data}