We are excited to announce the next major release of the Web Data Connector, version 2.0. The new version of the WDC will allow you to build more powerful connectors and adds support for multiple tables.
These features are in beta and may change.
So, why the change?
When the initial version of the WDC API was released with 9.1, it allowed you
to connect Tableau to all kinds of web data sources. Since then, the response to the WDC has been phenomenal! We’ve seen
hundreds of web data connectors built. But, as usual, there were some crucial limitations in the design of version 1.0 (wait, I can only bring back a single table?).
We’ve learned a lot since then, and we’ve received a large amount of helpful feedback from the developer community.
In response to that feedback, and in an effort to continue to empower you to connect to the data you care about,
we are excited to release version 2.0 of the web data connector API.
Important: This is a breaking change. Existing connectors will continue to work in future versions of Tableau. However, if you link an existing connector to version 2.0 of the WDC API, then you will have to update the connector to use the new API.
What’s new?
Version 2.0 includes two fundamental changes:
- You can include multiple tables of data.
- You can signal that you are done gathering data with a single callback, and you can add data that you gather directly to a table object created by Tableau. Previously, there was no way to signal that you were done gathering data. As a result, the WDC API repeatedly ran your
getTableData function so that you could pass data to Tableau through a callback parameter.
Differences between version 1 and version 2
In version 1:
- A connector loads and runs its interactive phase, then calls
tableau.submit().
- In the data gathering phase, Tableau calls
connector.getColumnHeaders(), which defines the schema for a single table. The getColumnHeaders() function finishes by calling a predefined callback.
- Tableau calls
connector.getTableData(), which passes data to Tableau by means of a parameter on the predefined tableau.dataCallback() function.
- Step 3 is repeated until
tableau.dataCallback() passes a flag to Tableau to signal that there is no more data.
In version 2:
- A connector loads and runs its interactive phase, then calls
tableau.submit().
- In the data gathering phase, Tableau calls
connector.getSchema(), which defines the schema for one or more tables. The connector calls a predefined callback to signal that it is done defining the table schema.
- Tableau calls
connector.getData() with a table object parameter and a callback parameter. The getData() function appends data to the table object using the object’s built-in table.appendRows() function. The getData() function is called once for each table defined in the schema.
- When the
getData() function is done gathering data, it calls the doneCallback() that it was passed as a parameter.
Preview of additional changes
Keep an eye on this page—we have a LOT of other features in the works. Here’s a preview of some of the things we’re working on:
- New Metadata APIs - Tell Tableau if your column is a dimension, a measure, discrete, continuous, a State, a Zip Code, an oddly formatted currency, and more!
- Clearer Authentication - Tell Tableau what your auth type is and when your connector has authentication needs.
- Whitelisting functionality on Tableau Server - you are no longer forced to use tabadmin import_webdataconnector.
- All new samples.
- A new community portal to browse community built connectors.
