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Data Source

Follow the instructions below to create a new data flow that ingests data from a Transport for London (TFL) source in Nexla.
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Transport For London (TFL)

Create a New Data Flow​

  1. To create a new data flow, navigate to the Integrate section, and click the New Data Flow button. Then, select the desired flow type from the list, and click the Create button.

  2. Select the Transport for London (TFL) connector tile from the list of available connectors. Then, select the credential that will be used to connect to the TFL API, and click Next; or, create a new TFL credential for use in this flow.

  3. In Nexla, TFL data sources can be created using pre-built endpoint templates, which expedite source setup for common TFL endpoints. Each template is designed specifically for the corresponding TFL endpoint, making source configuration easy and efficient.
    • To configure this source using a template, follow the instructions in Configure Using a Template.

    TFL sources can also be configured manually, allowing you to ingest data from TFL endpoints not included in the pre-built templates or apply further customizations to exactly suit your needs.
    • To configure this source manually, follow the instructions in Configure Manually.

Configure Using a Template​

Nexla provides pre-built templates that can be used to rapidly configure data sources to ingest data from common TFL endpoints. Each template is designed specifically for the corresponding TFL endpoint, making data source setup easy and efficient.

Endpoint Settings​

  • Select the endpoint from which this source will fetch data from the Endpoint pulldown menu. Available endpoint templates are listed in the expandable boxes below. Click on an endpoint to see more information about it and how to configure your data source for this endpoint.

    Get air quality feed

    This endpoint template retrieves air quality data feed from the Transport for London API. Use this template when you need to access real-time air quality information for London for analysis, reporting, or integration purposes.

    • This endpoint automatically retrieves air quality data from the TFL API. No additional configuration is required beyond selecting this endpoint template.

    This endpoint returns real-time air quality data feed from the Transport for London API, including air quality indices, pollutant levels, and other air quality metrics. The endpoint returns current air quality information for London.

    For detailed information about air quality data, API response structures, and available air quality metrics, see the TFL API Portal documentation.

    Gets the list of available StopPoint modes

    This endpoint template retrieves a list of available StopPoint modes from the Transport for London API. Use this template when you need to access information about available transportation modes (e.g., bus, tube, train) for analysis, reporting, or integration purposes.

    • This endpoint automatically retrieves all available StopPoint modes from the TFL API. No additional configuration is required beyond selecting this endpoint template.

    This endpoint returns a list of available StopPoint modes from the Transport for London API, including mode IDs, names, and other mode metadata. Use this endpoint to discover available transportation modes for use with other endpoints.

    For detailed information about StopPoint modes, API response structures, and available mode data, see the TFL API Portal documentation.

Endpoint Testing​

Once the selected endpoint template has been configured, Nexla can retrieve a sample of the data that will be fetched according to the current settings. This allows users to verify that the source is configured correctly before saving.

  • To test the current endpoint configuration, click the Test button to the right of the endpoint selection menu. Sample data will be fetched & displayed in the Endpoint Test Result panel on the right.

  • If the sample data is not as expected, review the selected endpoint and associated settings, and make any necessary adjustments. Then, click the Test button again, and check the sample data to ensure that the correct information is displayed.

Configure Manually​

TFL data sources can be manually configured to ingest data from any valid TFL API endpoint. Manual configuration provides maximum flexibility for accessing endpoints not covered by pre-built templates or when you need custom API configurations.

With manual configuration, you can also create more complex TFL sources, such as sources that use chained API calls to fetch related data or sources that require custom query parameters or filters.

API Method​

  1. To manually configure this source, select the Advanced tab at the top of the configuration screen.

  2. Select the API method that will be used for calls to the TFL API from the Method pulldown menu. TFL API typically uses GET method for retrieving data from endpoints.

API Endpoint URL​

  1. Enter the URL of the TFL API endpoint from which this source will fetch data in the Set API URL field. This should be the complete URL to your TFL endpoint (e.g., https://api.tfl.gov.uk/AirQuality, https://api.tfl.gov.uk/StopPoint/Meta/Modes). The Application Key from your credential will be automatically appended as the app_key query parameter. Include any additional required query parameters in the URL.

Ensure the API endpoint URL is correct and accessible with your current credentials. The TFL API endpoint URL should include the API base URL (https://api.tfl.gov.uk/) and the resource path. The Application Key from your credential will be automatically appended as the app_key query parameter. You can test the endpoint using the Test button after configuring the URL.

Response Data Path​

  1. Enter the JSONPath expression in the Response Data Path field to specify which part of the API response should be treated as the relevant data by Nexla. For TFL API responses, use $ to extract the entire response object, $[*] to extract all items from a response array, or $.{field}[*] to extract items from a specific field array, depending on your endpoint.

The JSONPath expression must correctly reference the structure of your TFL API response. TFL API responses may have different structures depending on the endpoint. Ensure your JSONPath expression matches the structure returned by your specific endpoint. The JSONPath expression determines which data will be extracted and processed by Nexla.

Pagination (if applicable)​

  1. If your endpoint supports pagination, configure the pagination settings in the Pagination section. TFL API may use different pagination mechanisms depending on the endpoint. Select the pagination type that matches your endpoint's pagination mechanism.

  2. Configure the pagination parameters based on your selected pagination type. For incrementing page-based pagination, specify the page parameter name, page size parameter name, and starting page number.

Save the Data Source​

  1. Once all of the relevant steps in the above sections have been completed, click the Next button to proceed with the rest of the data flow configuration, or click Save to save the data source configuration for later use.