Working with Feeds and Feed Elements

Capabilities

As part of the effort to diversify the feed, pieces of functionality found in feed elements have been broken out into capabilities. Capabilities provide a consistent way to interact with objects in the feed. Instead of inspecting feed element type and using other indirect means to determine which functionality is available for a specific feed element, the capability object tells you explicitly what’s available. Check for the presence of a capability to determine what a client can do to a feed element.

The ConnectApi.FeedElement.capabilities property holds a ConnectApi.FeedElementCapabilities object, which holds a set of capability objects.

A capability object includes both an indication that a feature is possible and data associated with that feature. If a capability property exists on a feed element, that capability is available, even if there isn’t any data associated with the capability yet. For example, if the chatterLikes capability property exists on a feed element (with or without any likes included in the list of likes found in the chatterLikes.page.items property), the context user can like that feed element. If the capability property doesn’t exist on a feed element, it isn’t possible to like that feed element.

When posting a feed element, specify its characteristics in the ConnectApi.FeedElementInput.capabilities property.

How the Salesforce UI Displays Feed Items

As we learned in Capabilities, a client should use the ConnectApi.FeedElement.capabilities property to determine what it can do with a feed element and how it should render a feed element. For all feed element subclasses other than ConnectApi.FeedItem, the client doesn’t need to know the subclass type, it can simply look at the capabilities. Feed items do have capabilities, but they also have a few properties, such as actor, that aren’t exposed as capabilities.For this reason, clients must handle feed items a bit differently than other feed elements.

To give customers a consistent view of feed items and to give developers an easy way to create UI, the Salesforce UI uses one layout to display every feed item. The layout always contains the same pieces and the pieces are always in the same position; only the content of the layout pieces changes.

These are the feed item (ConnectApi.FeedItem) layout elements:

1. Actor (ConnectApi.FeedItem.actor)—A photo or icon of the creator of the feed item. (You can override the creator at the feed item type level. For example, the dashboard snapshot feed item type shows the dashboard as the creator.)
2. Header (ConnectApi.FeedElement.header)—Provides context. The same feed item can have a different header depending on who posted it and where. For example, Gordon posted this feed item to his profile. If he then shared it to a group, the header of the feed item in the group feed would be “Gordon Johnson (originally posted by Gordon Johnson)” and the “originally posted” text would link to the feed item on Gordon’s profile.
3. Body (ConnectApi.FeedElement.body)—All feed items have a body, but the body can be null, which is the case when the user doesn’t provide text for the feed item. Because the body can be null you can’t use it as the default case for rendering text. Instead, use the ConnectApi.FeedElement.header.text property, which always contains a value.
4. Auxiliary Body (ConnectApi.FeedElement.capabilities)—The visualization of the capabilities. See Capabilities.

   The attachment property is not supported in API versions 32.0 and later. Instead, use the capabilities property, which holds a ConnectApi.FeedElementCapabilities object, to discover what to render for a feed element.

   Important

5. Created By Timestamp (ConnectApi.FeedElement.relativeCreatedDate)—The date and time when the feed item was posted. If the feed item is less then two days old, the date and time are formatted as a relative, localized string, for example, “17m ago” or “Yesterday”. Otherwise, the date and time are formatted as an absolute, localized string.

Here’s another example of a feed item in the Salesforce UI. This feed item’s auxiliary body contains a poll capability:

How the Salesforce Displays Feed Elements other than Feed Items

As we learned in the Capabilities section, a client should use the ConnectApi.FeedElement.capabilities property to determine what it can do with a feed element and how it should render a feed element. This section uses bundles as an example of how to render a feed element, but these properties are available for every feed element. Capabilities allow you to handle all content in the feed consistently.

To give customers a clean, organized feed, Salesforce aggregates feed-tracked changes into a bundle. To see individual feed elements, click on the bundle.

Feed Element Visibility

Feed Types

1ConnectApi.FeedElementPage newsFeedElementPage = 
2   ConnectApi.ChatterFeeds.getFeedElementsFromFeed(null, 
3      ConnectApi.FeedType.News, 'me');
4
5ConnectApi.FeedElementPage topicsFeedElementPage = 
6   ConnectApi.ChatterFeeds.getFeedElementsFromFeed(null, 
7      ConnectApi.FeedType.Topics, '0TOD00000000cld');

To get a filter feed, call one of the ConnectApi.ChatterFeeds.getFeedElementsFromFilterFeed methods. To get a favorites feed, call one of the ConnectApi.ChatterFavorites.getFeedElements methods.

Posting a Feed Item using postFeedElement

When you post a feed item, you create a child of a standard or custom object. Specify the parent object in the in the subjectId parameter or in the subjectId property of the ConnectApi.FeedElementInput object you pass in the feedElement parameter. The value of the subjectId parameter determines the feeds in which the feed item is displayed. The parent property in the returned ConnectApi.FeedItem object contains information about the parent object.

Getting Feed Elements from a Feed

Getting feed items from a feed is similar, but not identical, for each feed type.