Customize Your Connector


🕐 3 min read

To create your connector, we recommend that you first create a sample connector and edit those files. It’s easier to get all the files and directory structure your connector needs by just using an existing example.

Use the connector you created in the Get Started topic. Copy that sample connector directory to another directory. You’re now ready to create your own connector.

To create your connector, do the following steps.

Step 1: Configure your connector’s properties

In your new connector directory, find and open the connector.json file.

{
  "name": "my-first-connector",
  "version": "1.0.0",
  "tableau-version": {
    "min": "2022.3"
  },
  "vendor": {
    "name": "vendor-name",
    "support-link": "https://vendor-name.com",
    "email": "support@vendor-name.com"
  },
  "permission": {
    "api": {
      "https://*.usgs.gov/": [
        "GET",
        "POST",
        "HEAD"
      ]
    }
  },
  "auth": {
    "type": "none"
  },
  "window": {
    "height": 800,
    "width": 600
  }
}

Make the following changes:

  1. Change the general properties.

    Name Value
    name Your connector’s name. This is the name that appears in Tableau.
    version Your connector’s version
    min The earliest Tableau version your connector supports
  2. Change the company properties.

    Name Value
    vendor.name Your company name
    vendor.support-link Your company’s URL
    vendor.email Your company’s email
  3. Change the permissions.

    Name Value
    permission.api The URI for the API that the connector is allowed to access, along with the methods (POST, GET, PUT, PATCH, DELETE) that the connector is allowed to use.
  4. Change the auth type.

    Name Value
    auth.type Accepted values are custom, oauth, and none.

    Use none for your first test connector.

  5. Change the HTML pane size.

    Name Value
    window.height The height of the connector HTML pane
    window.width The width of the connector HTML pane

Step 2: Create the user interface

When you open a web data connector in Tableau, the connector displays an HTML page that links to your JavaScript code and to your connector’s handlers. Optionally, this page can also display a user interface for your users to select the data that they want to download.

To create a user interface for your connector, open the /app/index.html file.

<!DOCTYPE html>
<html>

<head>
  <title>USGS Earthquake Feed</title>
  <meta http-equiv="Cache-Control" content="no-store" />
  <link rel="shortcut icon" href="#" />
  <link href="index.css" rel="stylesheet" />
  <link rel="stylesheet" type="text/css" href="https://cdn.jsdelivr.net/npm/toastify-js/src/toastify.min.css">
  <script src="index.js" type="module"></script>
</head>

<body style="background-color: white;">
  <p id="error" style="display: block; margin-top: 2em; height: 5px; text-align: center; color: red;"></p>
  <div class="box">
    <button type="button" id="submitButton" disabled>Please wait while settings
      load...</button>
  </div>
  </div>
</body>

</html>

Let’s run through what the code is doing. Skipping over the standard markup for an HTML page, notice the following between the head tags:

Between the body tags, there’s a simple button element that illustrates how users can interact with your connector before getting data. In the next step, we’ll configure what happens when that button is clicked.

Step 3: Edit the connector object

Now that you’ve created a user interface, it’s time to edit the JavaScript code for the connector’s button. First, open the /app/index.js file.

import Connector from '@tableau/taco-toolkit'

function onInitialized() {
  const elem = document.getElementById('submitButton')
  elem.innerText = 'Get Earthquake Data!'
  elem.removeAttribute('disabled')
}

const connector = new Connector(onInitialized)

function submit() {
  connector.handlerInputs = [
    {
      fetcher: 'MyFetcher',
      parser: 'MyParser',
      data: {
        url: 'https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/4.5_week.geojson',
      },
    },
  ]
  connector.submit()
}

window.addEventListener('load', function () {
  document.getElementById('submitButton').addEventListener('click', submit)
})

Some notes about the code:

Step 4: Update the fetcher file

If your data is complex and needs preprocessing, use the TACO Toolkit library to prepare your data. The following is the default code that the fetcher uses to get the data:

import { Fetcher, FetchUtils } from '@tableau/taco-toolkit/handlers'

export default class MyFetcher extends Fetcher {
  async *fetch({ handlerInput }) {
    const data = handlerInput.data
    yield await FetchUtils.fetchJson(data.url)
  }
}

Step 5: Configure how the data is presented

Now you must define how you want to map the data to one or more or tables. This mapping of data is done in the schema.

To decide how to map your data, look at your data source. When you’re done looking at the summary of the JSON data source, make the necessary edits to structure the returned data.

import { Parser } from '@tableau/taco-toolkit/handlers'

export default class MyParser extends Parser {
  parse(fetcherResult, { dataContainer }) {
    const tableName = 'Earthquake Data'

    const containerBuilder = Parser.createContainerBuilder(dataContainer)
    const { isNew, tableBuilder } = containerBuilder.getTable(tableName)

    if (isNew) {
      tableBuilder.addColumnHeaders([
        {
          id: 'id',
          dataType: 'string',
        },
        {
          id: 'mag',
          alias: 'magnitude',
          dataType: 'float',
        },
        {
          id: 'title',
          alias: 'title',
          dataType: 'string',
        },
        {
          id: 'location',
          dataType: 'geometry',
        },
      ])
    }

    const { features } = fetcherResult
    if (features.length > 0) {
      tableBuilder.addRows(
        features.map(({ id, geometry: location, properties: { mag, title } }) => {
          return { id, mag, title, location }
        })
      )
    }

    return containerBuilder.getDataContainer()
  }
}

Step 6: Build your connector

Enter these commands to build, pack, and run your new connector:

taco build
taco pack
taco run Desktop