This document provides an overview of social applications and Chatter concepts in Salesforce, including posts, comments, following records, feeds, groups, profiles, and integrating Chatter into custom Visualforce pages. It describes how to query, create, and delete different Chatter object types through the API and restrictions on using Chatter components in Visualforce.

1. Social Applications
Sujit Kumar
Zenolocity LLC © 2012 - 2024

2. Chatter Overview
• Brings users together socially along with the
records from Force.com database that are
relevant to them.
• Concepts and Terms
• Data Model
• Add Chatter to custom VF User Interfaces

3. Chatter Concepts
• Posts and Comments
• Follow and Unfollow
• Feed
• Group
• Chatter Profile
• Digest
• Feed-tracked Change

4. Posts and Comments
• A post is a public message associated with a record in the database.
• A comment is also a public message, but related to an individual
post rather than a database record, like a footnote to the post.
• Viewable by anyone in the org who has access to the parent record.
• The body of posts and comments can contain text, searchable
topics (words prefaced with #), references to users in your
organization (using the @ character), and links to web pages.
• Posts and comments are full-text searchable from the standard
Force.com search interface.
• Posts and comments can also contain any type of file, like
attachments in email messages.
• Individual posts can be “liked” by users, helping to measure and
track the popularity of content.

5. Chatter Concepts
• Follow and Unfollow - refer to the social
relationship between a user and a DB record.
• Interests - set of records followed by a user.
• Feed : history of social activity for a DB record
with the most recent appearing first.
• Chatter Group is a gathering place for users to
collaborate on any subject.
• Chatter Profile

6. Digest
• Daily or weekly emailed summary of the
Chatter feeds followed by a user.
• Daily digest contains up to 25 of the most
recent posts, and the weekly digest has 50.
• Both include latest 3 comments for each post.
• Convenient way to keep track of social activity
without logging into Salesforce.

7. Feed-tracked change
• After an administrator configures an object
and field as feed-tracked, a system-generated
Chatter post is created to notify users when
the field’s value changes.
• The feed-tracked change Chatter posts serve
as a public audit trail, and cannot be deleted.
• Never included in chatter search results.

8. Chatter Configuration
• Administrators: Users with admin permissions
can enable and disable Chatter for the entire org.
Can also decide which database objects can
contain Chatter and which fields on those objects
have feed-tracked changes.
• Groups: can provide a meaningful set of Chatter
topics for your company. Similar to Facebook
groups.
• Users: can control email digests and notifications
of Chatter-related events, such as new posts or
new users following them.

9. Chatter Data Model
• Dynamic: Objects in Chatter schema can appear
and disappear based on the Chatter
configuration. For example, when Chatter is
disabled in an organization, the Chatter objects
are completely hidden, as if they never existed.
• Objects containing Chatter posts are dynamically
created when Chatter is enabled for a custom
object.
• Relationship Rich: links social and business data
• No updates allowed on chatter objects.

10. Chatter Posts
• Chatter enabled parent object has 0 or many
posts.
• <Object> 0 ---------> M <Object>Feed
• Example:
• if Chatter is enabled on the Proj__c custom
object, then an object named Proj__Feed exists,
the object used to store posts related to Projects.
If Chatter is later disabled for Proj__c, the
Proj__Feed object is removed from the
Force.com database.

11. 5 Types of Chatter Posts
• Text – text post
• URL – link post
• File – content post, file attached to a post
• Field Change – tracked change, generated by
Force.com itself and cannot be created by
users or programs.
• Status Update – user status update

12. Standard Object Feeds
• When chatter is enabled for org, most
standard objects have chatter feeds.
• Example: retrieve 10 most recent Chatter
posts on the Contact object.
SELECT ParentId, Body, Type, CreatedBy.Name,
CreatedDate
FROM ContactFeed
ORDER BY CreatedDate DESC LIMIT 10

13. Create & Delete Chatter Posts
• Create a post - can use the same code to create posts regardless of object type.
• Delete a post – code to delete posts is object specific and NOT generic.
// Create a post
public Id post(Id recordId, String text) {
FeedItem post = new FeedItem(ParentId = recordId, Body = text);
insert post;
return post.Id;
}
// Delete a post
public void deleteContactPost(Id postId) {
ContactFeed post = [ SELECT Id FROM ContactFeed
WHERE FeedPostId = :postId ];
delete post;
}

14. Custom Object Feeds
• Similar to standard objects with 2 differences.
• Naming scheme is slightly different.
Example: Proj__c custom object has chatter
object called Proj__Feed.
• A feed object does not exist until Chatter is
enabled on the custom object.

15. UserFeed and UserProfileFeed
• Separate feeds (UF, UPF) exist for the Chatter user profile as well as
the standard User object.
• UF – field tracked changes on your User object plus posts by other
users on your profile. Cannot query another user’s UF.
Example: SELECT ParentId, FeedPostId, Type, CreatedById,
CreatedDate FROM UserFeed
• UPF – superset of UF. Includes chatter from other objects followed
by the user. Can view the UPF from the perspective of any user by
specifying his UserId using the WITH keyword.
Example: SELECT ParentId, FeedPostId, Type, CreatedById,
CreatedDate FROM UserProfileFeed WITH UserId =
'00580000001opOPAAY'

16. Home Tab Feed
• Home tab aggregates all the posts and
comments you follow in one place.
• The Chatter appearing on the Home tab is also
accessible via API using the NewsFeed object.
• Queries on NewsFeed are limited in scope to
the user running the query.
SELECT ParentId, Body, Type, CreatedBy.Name,
CreatedDate FROM NewsFeed

17. Chatter Comments
• 1 object has 0 or more posts.
• 1 post has 0 or more comments.
• The <Object>Feed is a junction object
between <Object> and the FeedComment
object.
• Comment data is stored in a single, large
object called FeedComment that cannot be
queried directly.

18. Retrieve Chatter Comments
• Retrieve all the posts in the Proj__c custom
object feed, and for each post all of its
comments.
SELECT ParentId, Type, CreatedById,
CreatedDate, Body,
(SELECT CommentBody, CreatedById,
CreatedDate FROM FeedComments)
FROM Proj__Feed

19. Create and Delete Chatter Comments
// Create Comment
public Id comment(Id postId, String text) {
FeedComment comment = new FeedComment(
FeedItemId = postId, CommentBody = text);
insert comment;
return comment.Id;
}
• You cannot update a FeedComment record, but you can delete it.
// Delete comment
public void deleteComment(Id postId, Id commentId) {
Proj__Feed post = [ SELECT Id,
(SELECT Id from FeedComments WHERE Id = :commentId)
FROM Proj__Feed WHERE FeedPostId = :postId ];
delete post.FeedComments[0];
}

20. Feed-tracked Changes
• Provide an audit trail of modifications to a set of fields.
• For each record in an object that has feed-tracked
changes enabled, there can be many corresponding
feed-tracked change records.
• Each change record captures the original field value,
the new field value, the field name, and the new and
old currencies if multicurrency is enabled in the
organization and the field is a currency type.
• The change records for all objects in an org with feed-tracked
changes enabled are stored in a single object
called FeedTrackedChange.

21. Retrieve Feed-tracked Changes
• FeedTrackedChange cannot be queried or
modified in any way by any user, even an
administrator.
• Like Chatter comments, it must be queried
indirectly via its junction object.
SELECT ParentId, Type, CreatedById, CreatedDate,
(SELECT FeedItemId, FieldName, OldValue, NewValue
FROM FeedTrackedChanges)
FROM ContactFeed

22. Follow and Unfollow a Record
// Follow a record
public Id follow(Id recordId, Id userId) {
EntitySubscription e =
new EntitySubscription(
ParentId = recordId,
SubscriberId = userId);
insert e;
return e.Id;
}
// Unfollow a record
public void unfollow(Id subscriptionId) {
delete [ SELECT Id FROM EntitySubscription
WHERE Id = :subscriptionId ];
}

23. Chatter Components in Visualforce
• Feed Component: renders a list of Chatter posts and comments for the selected
record. It also provides a text box at the top for creating new posts. The selected
record is specified using the entityId attribute.
• feedWithFollowers Component: embeds the full Chatter toolbar. It includes the
functionality of the feed component, and adds the list of followers to the right
side, the Show/Hide Chatter buttons, and the Follow/Unfollow buttons.
• Follow Component: Including this component on a page renders a Follow button if
the user is not following the record, and Unfollow button otherwise.
• Followers Component: displays a list of users following the current record. Users
are represented as thumbnail photos, which can be clicked to drill into their
profiles.
• showChatter Attribute: attribute of the detail component, if set to true, includes
the full Chatter toolbar at the top of the detail page.

24. Restrictions Chatter in Visualforce
• A Visualforce page cannot contain more than 1 of the 5
Chatter components at one time. If you attempt to use
more than one, the page cannot be saved.
• Chatter components cannot be added to a Visualforce
page unless the API version of the page is at least 20.0.
If the API version is set incorrectly, an Unknown
Component error will prevent the page from being
saved.
• You cannot use Chatter components with Visualforce
Sites. The Chatter components will be invisible to Sites
users.

25. Example of Chatter in Visualforce
<apex:page standardController="Proj__c">
<apex:sectionHeader title="Project"
subtitle="{!record.Id}" />
<apex:pageBlock title="Chatter Components">
<chatter:feedWithFollowers
entityId="{!record.Id}" />
</apex:pageBlock>
</apex:page>