Step 1: Get the Chatter Feed and Group Data

1swfobject.registerObject("clippy.codeblock-0", "9");global class GroupFeedController{
2    
3    // Declare and assign values to strings to use as method parameters.
4    private static String communityId = null;
5    private static String userId = 'me';
6    
7    // Holds the ID of the selected group.
8    // Pass this property to getFeedItemsFromFeed to get the group's feed.
9    global String groupId { get; set; }
10 
11    // Get the IDs and names for all of the groups 
12    // the logged-in user is a member of. Add them to
13    // a List of SelectionOption objects. This List populates
14    // the drop-down menu in the GroupFeed custom component.
15    global static List<SelectOption> getGroupOptions() {
16        List<SelectOption> options = new List<SelectOption>();
17        
18        // Adds a blank option to display when the page loads.
19        options.add(new SelectOption('', ''));
20        
21        // Declare and assign values to strings to use as method parameters. 
22        Integer page = 0;        
23        Integer pageSize = 100;
24        
25        // Use Chatter in Apex to get the names and IDs of every group
26        // the logged-in user is a member of.
27        // Chatter in Apex classes are in the ConnectApi namespace.
28        // communityId -- a community ID or null.
29        // userId -- the user ID or the keyword 'me' to specify the logged-in user.
30        // page -- the page number to return.
31        // pageSize -- the number of items on the page.
32        ConnectApi.UserGroupPage groupPage = ConnectApi.ChatterUsers.getGroups(communityId, userId, page, pageSize);
33        
34        // The total number of groups the logged-in user is a member of.
35        Integer total = groupPage.total;
36        
37        // Loop through all the groups and add each group's id and name
38        // to the list of selection options.
39        while (page * pageSize < total) {
40            // groupPage.groups is a List of ConnectApi.ChatterGroupSummary objects.
41            // ChatterGroupSummary is a subclass of ChatterGroup.
42            // For each ChatterGroup object in the List...
43            for (ConnectApi.ChatterGroup grp : groupPage.groups) {
44                // Add the group's ID and name to the list of selection options.
45                options.add(new SelectOption(grp.id, grp.name));
46            }
47           
48            page++;
49            
50            if (page * pageSize < total) {
51                // Get the next page of groups.
52                groupPage = ConnectApi.ChatterUsers.getGroups(communityId, userId, page, pageSize);
53            }
54        }
55        
56        // Return the list of selection options.
57        return options;
58    }
59    
60    // Get the feed items that make up a group's feed.
61    global List<ConnectApi.FeedItem> getFeedItems() {
62        if (String.isEmpty(groupId)) { return null; }
63        // To get the feed for a group, use the Record feed type and pass a group ID.
64        // getFeedItemsFromFeed returns a ConnectApi.FeedItemPage class.
65        // To get the List of ConnectApi.FeedItem objects,
66        // add the .items property to the call.
67        return ConnectApi.ChatterFeeds.getFeedItemsFromFeed(communityId, ConnectApi.FeedType.Record, groupId).items;
68    }
69    
70    public PageReference choose() {
71        return null;
72    }
73    
74}