Preventing a class from firing based on the current user Profile?

Question

I'm not certain how to make the below class, which is called from a trigger on Chatter posts, (it prevents users from posting in Chatter, unless related to a group, or a subset of Objects) also evaluate for the user profile.

Basically, there are 'superusers' that should be able to post anywhere, while the rest are held to the below rules. So the logic would be "if the current user is "Business Super User" profile, then ignore the rest of the class. I believe I can evaluate the current user profile as the first IF statement?

public with sharing class ChatterPostValidation {
    public static Boolean isChatterPostAllowed(FeedItem feedItem) {
        //ParentName is the name of where the post is going
        //e.g. "CollaborationGroup" means it's being posted to a chatter group
        String ParentName = feedItem.ParentId.getSObjectType().getDescribe().getName();

        //check if place being posted is one of the following:
        //chatter group, account (firm), contact, deal     
        if ('CollaborationGroup'.Equals(ParentName)) {
                return true;
        }
        if ('Account'.Equals(ParentName)            ||
            'Contact'.Equals(ParentName)            ||
            'Investment__c'.Equals(ParentName)) {
            return true;
        }
        return false;
    }
}

Answer 1

You should use the UserInfo class

Id profileId=userinfo.getProfileId();
String profileName=[Select Id,Name from Profile where Id=:profileId].Name;
system.debug('ProfileName' + profileName);
if(profile == 'BusinessSuperUser'){
   //Code Statements
}

To help you testing it, you should use the runAs method.

Answer 2

You can absolutely whitelist/exempt certain Profiles from validation.

public with sharing class ChatterPostValidation {
    public static Set<Id> exemptProfileIds
    {
        get
        {
            if (exemptProfileIds == null)
            {
                exemptProfileIds = new Set<Id>();
                for (Profile exemptProfile : [SELECT Id FROM Profile]) // WHERE ...
                {
                    exemptProfileIds.add(exemptProfile.Id);
                }
            }
            return exemptProfileIds;
        }
        private set;
    }
    public static Boolean isChatterPostAllowed(FeedItem feedItem) {
        if (exemptProfileIds.contains(UserInfo.getProfileId())) return true
        // rest of check
    }
}