One of the most powerful aspects of Google Apps Script is its ability to automate tasks. While you can run scripts manually, true automation comes from triggers. Triggers are essentially event handlers that allow your scripts to execute automatically in response to specific events within Google Workspace.
Apps Script offers two main types of triggers: time-driven triggers and event-driven triggers. Understanding these will unlock a new level of efficiency in your daily work.
Time-driven triggers allow you to schedule your scripts to run at specific intervals. This is perfect for recurring tasks like generating daily reports, cleaning up old data, or sending out weekly summaries.
You can set up time-driven triggers to run every minute, every hour, once a day, once a week, or once a month. The granularity depends on your needs. To set one up, navigate to your script editor, click the clock icon on the left sidebar (Triggers), and then click 'Add Trigger'.
Event-driven triggers, on the other hand, are activated by actions taken within your Google Workspace applications. These are incredibly versatile for real-time automation.
Common event-driven triggers include:
- On Open: Runs automatically when a user opens a Google Sheet, Doc, or Slide file.
- On Edit: Runs automatically when a user edits a cell in a Google Sheet.
- On Form Submit: Runs automatically when a user submits a Google Form linked to a Sheet.
- On Change: Runs automatically when the structure of a Google Doc changes (e.g., adding or deleting sections).
- Custom Events: These are more advanced and allow you to create your own events to trigger scripts, often by publishing an app and subscribing to events from it.
To set up an event-driven trigger, you can often do so directly within the application's interface (e.g., in the script editor's Triggers menu, select the relevant event type like 'From spreadsheet'). For some events, like 'On Open' or 'On Edit' in Sheets, you can also select them when adding a new trigger in the script editor.
graph TD
A[Script Execution Triggered]
B{Trigger Type?}
A --> B
B --> C[Time-Driven Trigger]
B --> D[Event-Driven Trigger]
C --> C1[Scheduled Interval]
C1 --> E[Run Script]
D --> D1[User Action]
D1 --> E
E --> F[Perform Automated Task]