Chapter 2: Hello World!

Now that we’ve added the trexjacket dependency and connected our Anvil app to our Tableau Dashboard using a .trex file, let’s use Anvil X to access the dashboard from Anvil by adding some code to Form1.

Open up Form1 and click on the “code” button at the top. At the code near the top of the form, import get_dashboard from trexjacket.api import get_dashboard and create an instance of the dashboard in the form:

from ._anvil_designer import Form1Template
from anvil import *
from anvil import tableau

from trexjacket.api import get_dashboard
dashboard = get_dashboard()

class Form1(Form1Template):
  def __init__(self, **properties):
    self.init_components(**properties)
    print('Hello, World!')

Tip

dashboard is an instance of the Dashboard class, that has gives you access to your dashboard elements, things like filters, parameters, datasources, and marks on the dashboard.

After adding the Form1 code, let’s see our changes in action. We’ve already added our Extension to our dashboard, but because we’ve changed our app in Anvil we’ll need to reload the extension in Tableau. To do this:

• Click inside your extension inside Tableau and click the grey, downward facing caret icon

• Click “Reload”

Once you’ve reloaded your extension, you should see the output of your “Hello, World!” statement in the “Tableau Output 1” pane inside Anvil (see gif).