subscribe method

bool subscribe(
  1. String topic,
  2. Function callback
)

Registers a callback to listen for the specified event topic.

Returns true if the callback was added, false if it was already added.

Implementation

bool subscribe(String topic, Function callback) {
  if (!_cache.containsKey(topic)) {
    _cache[topic] = [];
  }
  if (!_cache[topic]!.contains(callback)) {
    _cache[topic]!.add(callback);
    return true;
  }
  return false;
}