API Reference


In this section


Use the Tableau Analytics Extensions REST API to extend Tableau calculations dynamically to include popular data science programming languages and external tools and platforms.

API Version 1 (Implemented in Tableau 2020.1+)

Tableau Implementation

The methods in this section are implemented in Tableau products as of version 2020.1. In Tableau Desktop, the ‘Test Connection’ button in the Analytics Extension connection dialogue will call the /info method to determine if authentication is required and test if the analytics extension can be connected to succesfully. When SCRIPT_X calculations execute in Tableau Desktop and Server they call the /info and the /evaluate methods to establish authentication and evaluate the code or function call.

GET /info

Get static information about the server. This is used for Tableau to understand how the analytics extension is configured. It returns data about the service, such as whether authentication is required. It helps Tableau understand what’s sitting on the other side and what Tableau should be passing.

URL

/info

Method

GET

URL parameters

None.

Data Parameters

None.

Response

For a successful call:

Response fields:

Property Description
description String that is hard coded in the state.ini file and can be edited there.
creation_time Creation time in seconds since 1970-01-01, hard coded in the state.ini file, where it can be edited.
state_path State file path of the server.
server_version The server version tag. Clients can use this information for compatibility checks.
name The server instance name. Can be edited in state.ini file.
version Collection of API versions supported by the server. Each entry in the collection is an API version which has a corresponding list of properties.
version.<ver> Set of properties for an API version.
version.<ver>.features Set of an API’s available features.
version.<ver>.features.<feature> Set of a feature’s properties. For specific details for a particular property meaning of a feature, check the documentation for the specific API version.
version.<ver>.features.<feature>.required If true the feature is required to be used by client.

Example:

curl -X GET http://localhost:9004/info

Authentication

When authentication is enabled for v1 API /info call, the response contains the authentication feature parameter, e.g.:

  {
      "description": "",
      "creation_time": "0",
      "state_path": "e:\\dev\\server\\server\\server",
      "server_version": "0.4.1",
      "name": "Server",
      "versions": {
          "v1": {
              "features": {
                  "authentication": {
                      "required": true,
                      "methods": {
                          "basic-auth": {}
                      }
                  }
              }
          }
      }
  }

v1 authentication specific features (see the example above):

Property Description
required Authentication is never optional for a client to use if it is in the features list. Both settings of true or false will result in a requirement for authentication.
methods List of supported authentication methods with their properties.
methods.basic-auth HTTP basic authentication.

POST /evaluate

Executes a block of code, replacing named parameters with their provided values. The Evaluate endpoint is where all of the analysis using the service is done.

The expected POST body is a JSON dictionary with two elements:

Example request:

POST /evaluate HTTP/1.1
Host: localhost:9004
Accept: application/json

{"data": {"_arg1": 1, "_arg2": 2}, "script": "return _arg1+_arg2"}

Example response:

HTTP/1.1 200 OK
Content-Type: application/json

[
                4,
                1,
                8
]

Tableau expects the /evaluate method to return either:

If a scalar value is returned, that value will be assigned to the calculated field in Tableau for each row in the field.

If an array response is returned, the number of elements in the array must exactly match the number of rows in the calculated field that the response will be assigned to. Usually, this is done by sending from Tableau an array with the right number of elements as an input parameter in the /evaluate request body. The Analytics Extension should then return an array of the same size as the input parameter.

Using curl:

curl -X POST http://localhost:9004/evaluate \
-d '{"data": {"_arg1": 1, "_arg2": 2}, "script": "return _arg1 + _arg2"}'