🕐 4 min read
The earthquake data JavaScript (JS) boilerplate connector is a connector connecting to earthquake data and contains simple JavaScript and HTML.
To create your connector, we recommend that you first create a sample earthquake data connector and edit the generated files. It’s easier to get all the files and directory structure your connector needs by just using an existing example.
To create your earthquake data connector, do the following steps.
Enter the following command to create the connector:
taco create my-eq-data-js-connector --boilerplate earthquake-data-js
This creates a directory with the earthquake data boilerplate code, which is included with the toolkit.
my-eq-data-js-connector
directory.
cd my-eq-data-js-connector
Build the connector by entering the following command:
taco build
This command clears any previous or existing build caches, then installs the dependencies, then builds the frontend code and the backend code (handlers), then copies the connector.json file (the configuration file).
In your new earthquake data connector directory, find and open the connector.json
file.
{
"name": "my-eq-data-js-connector",
"version": "1.0.0",
"tableau-version": {
"min": "2023.3"
},
"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:
Change the general properties.
Name | Value |
---|---|
name | Your connector’s directory name |
version | Your connector’s version |
min | The earliest Tableau version your connector supports |
Change the company properties.
Name | Value |
---|---|
vendor.name | Your company name |
vendor.support-link | Your company’s URL |
vendor.email | Your company’s email |
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. |
Verify the authentication type.
Name | Value |
---|---|
auth.type | Enter none |
For more information about authentication, see the Authentication section in the Considerations for Building Your Connector topic.
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 |
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="icon" href="data:,">
<link href="index.css" rel="stylesheet" />
<script src="index.js" type="module" defer></script>
</head>
<body>
<div class="box">
<button type="button" id="submitButton" disabled>
Please wait while settings load...
</button>
</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:
meta
tag prevents your browser from caching the page.index.css
file is used to simplify styling and formatting.index.js
file is the code for your connector.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.
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()
}
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 /handlers/MyFetcher.js
files 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)
}
}
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 in the /handlers/MyParser.js
file 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()
}
}
Some notes:
Enter these commands to build, pack, and run your new connector:
taco build
taco pack
taco run Desktop