How to get subtopic related to Community topic in apex?

Question

Have set of Topics and subtopics in community, I would like to get the subtopic related to particular topic throw apex code.

Answer 1

there is a method for it ConnectApi (reference). I think you need to use that.

ConnectApi.ManagedTopicCollection topics = ConnectApi.ManagedTopics.getManagedTopics(communityId);
for (ConnectApi.ManagedTopic managedTopic : topics.managedTopics) {
    System.debug('###managedTopic.topic.name = ' + ((ConnectApi.Topic)managedTopic.topic).name);

    Set<String> topicNames = new Set<String>();
    for (ConnectApi.ManagedTopic childManagedTopic : managedTopic.children) {
        topicNames.add(((ConnectApi.Topic)childManagedTopic.topic).name + '\n');
    }

    System.debug('### childTopicNames:\n' + String.join(topicNames, '\n'));
}

Answer 2

The children become visible when you provide the depth parameter

Integer depth =2;
ConnectApi.ManagedTopicCollection topics = ConnectApi.ManagedTopics.getManagedTopics(communityId,ConnectApi.ManagedTopicType.Navigational,depth);