12) Separation of Concerns

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Separation of Concerns

In JDA we follow the pattern of Separation of Concerns (SoC) for our entities. This means that updates and moderation all happens in dedicated classes rather than on the entities themself (with a few exceptions like deletion)

Each entity that can be updated directly has a Manager instance which can be used to update one or more of the entity properties such as its name.

Managers

The managers in JDA are useful to update entities without much complications, you can update all of the properties in a single RestAction execution (http request).

Updating an Entity

We will make a small example here on how to update the name and the topic of a TextChannel.

public void updateChannel(TextChannel channel) {
    ChannelManager manager = channel.getManager(); // get the manager
    manager.setName("testing-2").setTopic("This is a testing channel, no memes allowed"); // set the new values
    manager.queue(); // execute update, this updates both name and topic
}

Note: queue() is async so the update is not done when this method returns!

Re-usability of Managers

Every manager in JDA is cached for re-use and can be updated for an interval and then executed upon command, very useful for bots!

Example-State-Machine

Exceptions to SoC Pattern

The only exceptions we have are deletion and creation. All entities are deleted directly using its delete() method, for instance Channel.delete().

You can create copies of entities in the same fashion with one twist. Some createCopy() methods allow you to modify the new copy before execution of the RestAction

public void copyChannel(Channel channel, String newName) {
    channel.createCopy().setName(newName).queue();
}

Note: This will copy the provided Channel and set its name to the provided newName!

These things can be overlooked, so we do recommend to inspect the return type of these operations: getManager(), create...(), delete(), ban(...), kick(...), etc.