General Hooks

This section will show how the general hooks are processed, These hooks include:

• on-receive
• on-generate
• template
• middleware
• validator

Any hook can have other business logic in it e.g A template hook can return the required dynamic data but it may also have logic to do other processes on it. E.g save some data to user session or call another service. A middleware hook might validate some input etc

Consider the example for on-receive below

The example below works for on-receive, on-generate, middleware, validator hooks

Example Hook: On-Receive#

1000:
  type: text
  on-receive: "rest:https://example.com/api/notify"
  message: "Type `yes` to receive a Slack notification from us"
  routes:
    "yes": "next-stage"

When user responds and on-receive is defined, the hook is processed.

To define REST API based hooks, prefix them with rest:

Each rest based hook must be a POST request which accepts a HookArgs object

Consider a sample rest hook

# ...
# using FAST API

# constant prop key in engine session
ENGINE_PROP_KEY = "kProps"

@app.post("/notify")
def slack_notify(args: HookArgs):
    print("Received args: {}".format(args))

    user_props_data = get_data_from_session(
        user=args.channelUser.waId,
        data_key=ENGINE_PROP_KEY
    )

    # assume there was a template that asked user for
    # their Slack Id and had a prop key of `slack_id`
    slack_response = notify_via_slack(slack_id=user_props_data.get('"slack_id"'))

    return args

@RestController
@RequestMapping("/notify")
class SlackService {
   @PostMapping
   public HookArgsRest notify(@RequestBody HookArgsRest args) {
   //   ... handle send notification
     return args;
   }
}