I've set up a simple trigger to insert a FeedPost when one of my Customer Portal Users creates an entry through Sites and found that the trigger only works when I create an entry from inside Salesforce (as a regular SF user).

When a Customer Portal User creates an entry, the trigger fails with the error: "Invalid type: FeedPost"  

The API version on all the code is 18.0.

I've also tried putting the "insert FeedPost" call in a class without sharing, but it still fails in the Customer Portal context.

What are the limitations on integration Chatter with Sites and Customer Portal Users?   Can we even trigger chatter activity from portal user actions?

- R

(This is just a test case ... I know the trigger isn't set up to handle bulk inserts)

trigger ItemReview on Item_Review__c (after insert) {

	
	for (Item_Review__c review :trigger.new) {
		Chatter.feedPost(review.Item__c,  'A review has been posted for this item.'
				,null);
		
	}

}

public without sharing class Chatter {

	public static void feedPost(String parentId, String body, String link) {
		try {
		   FeedPost fpost = new FeedPost();
		   fpost.ParentId = parentId; //eg. Opportunity id, custom object id..
    		    fpost.Body = body;
    		    insert fpost;	
            	 
        } Catch (Exception ex) {
            	
        }
		
	}
}