Triggers
Now let’s see what a trigger is and how to use it.
We can define a trigger as an object representing an event source that triggers the execution of actions. When activated by an event, associated actions are executed.
In other words, a trigger is a mechanism that listens for specific events or conditions and initiates actions in response to those events. It acts as the starting point for a workflow.
Example: Sending Slack Notifications
Let’s consider a scenario where we want to send Slack notifications when users visit specific pages and submit a contact form.
Step 1: Define the Trigger
We create a trigger named "PageVisitTrigger" that listens for events related to user visits on our website. To create it, you can use the following command:
$ nuv trigger create PageVisitTriggerOnce the trigger is created, you can update it to add parameters, such as the page parameter:
$ nuv trigger update PageVisitTrigger --param page homepage
Of course, there are not only create and update, but also delete, and they work as expected, updating and deleting triggers. In the next paragraph, we will also see the fire command, which requires you to first create rules to do something useful.
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Step 2: Associate the Trigger with an Action
Next, we create an action named "SendSlackNotification" that sends a notification to Slack when invoked. Then, we associate this action with our "PageVisitTrigger" trigger, specifying that it should be triggered when users visit certain pages.
To associate the trigger with an action, you can use the following command:
$ nuv rule create TriggerRule PageVisitTrigger SendSlackNotificationWe’ll have a better understanding of this aspect in Rules
In this example, whenever a user visits either the homepage or the contact page, the "SendSlackNotification" action will be triggered, resulting in a Slack notification being sent.