1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
module ActionCable
module Channel
class Base
include Callbacks
include Streams
on_subscribe :start_periodic_timers
on_unsubscribe :stop_periodic_timers
attr_reader :params, :connection
delegate :logger, to: :connection
class << self
def matches?(identifier)
raise "Please implement #{name}#matches? method"
end
end
def initialize(connection, channel_identifier, params = {})
@connection = connection
@channel_identifier = channel_identifier
@_active_periodic_timers = []
@params = params
perform_connection
end
def perform_connection
logger.info "#{channel_name} connecting"
connect
run_subscribe_callbacks
end
def perform_action(data)
if authorized?
action = extract_action(data)
if performable_action?(action)
logger.info channel_name + compose_signature(action, data)
public_send action, data
else
logger.error "#{channel_name} failed to process #{compose_signature(action, data)}"
end
else
unauthorized
end
end
def perform_disconnection
disconnect
run_unsubscribe_callbacks
logger.info "#{channel_name} disconnected"
end
protected
# Override in subclasses
def authorized?
true
end
def unauthorized
logger.error "#{channel_name}: Unauthorized access"
end
def connect
# Override in subclasses
end
def disconnect
# Override in subclasses
end
def transmit(data, via: nil)
if authorized?
logger.info "#{channel_name} transmitting #{data.inspect}".tap { |m| m << " (via #{via})" if via }
connection.transmit({ identifier: @channel_identifier, message: data }.to_json)
else
unauthorized
end
end
def channel_name
self.class.name
end
private
def extract_action(data)
(data['action'].presence || :receive).to_sym
end
def performable_action?(action)
self.class.instance_methods(false).include?(action)
end
def compose_signature(action, data)
"##{action}".tap do |signature|
if (arguments = data.except('action')).any?
signature << "(#{arguments.inspect})"
end
end
end
def run_subscribe_callbacks
self.class.on_subscribe_callbacks.each { |callback| send(callback) }
end
def run_unsubscribe_callbacks
self.class.on_unsubscribe_callbacks.each { |callback| send(callback) }
end
def start_periodic_timers
self.class.periodic_timers.each do |callback, options|
@_active_periodic_timers << EventMachine::PeriodicTimer.new(options[:every]) do
worker_pool.async.run_periodic_timer(self, callback)
end
end
end
def stop_periodic_timers
@_active_periodic_timers.each { |timer| timer.cancel }
end
def worker_pool
connection.worker_pool
end
end
end
end
|