Topics

REST Connector topics are collections of tags. Each tag defines a URL to communicate with the REST service. Topic settings apply to all tags within the topic.

Add Topics

To add topics, click the “Add” button with the REST connector’s “Topics” node selected in the main application’s nagivation pane.

../_images/rest-add-topics.png

Topic Settings

For each topic you can configure:

  • Name

    The topic’s name.

  • Access

    Either “Read-Only”, “Read and Write”, “Write-Only”, or “Process”. Initially the topic is “Read-Only” and all requests sent to the REST service are “GET” requests. Topics with “Read” access may be used as inputs in tasks; topics with “Write” access may be used as outputs. Writable topics offer the additional option to select the “Write” method for sending data to the REST service (see below).

    “Process” topics may have inputs and outputs for integration into task logic. After changing the topic access to “Process”, select a suitable request method and enter additional input tag names in the entry field provided.

  • Read Rate

    The read rate (in milliseconds) determines how often “GET” requests are sent to the REST service to fetch data. Ensure that the REST service is performant enough to respond to periodic requests at the configured rate.

  • Write Method

    A “Write” method may be selected for topics with “Write” access. Supported “Write” methods are: “PATCH”, “PUT” and “POST”. Select the appropiate method for the intended use.

  • Process Method

    A “Process” method may be selected for topics with “Process” access. Supported “Process” methods are: “GET”, “PATCH”, “PUT” and “POST”. Select the appropiate method for the intended use.

For “Process” access the following additional settings are available.

  • Do not retry failed requests
    If checked, then failed requests are not retried. Task logic should be used to handle retries.

For “Process” access with a process method other than “GET” the following additional settings are available.

  • Input values are JSON objects
    If checked, then values sent to the topic inputs are expected to be JSON objects. These are sent in requests as an array of JSON objects. If unchecked, then input values are url-encoded as key-value pairs.

Press the “Apply” button to commit any changes.

Remove Topics

Remove topics by selecting “Topics” in the navigation panel, then select one or more topics to remove in the content panel, and finally click on the “Remove” toolbar button to remove selected topics.

../_images/rest-remove-topics.png

Warning

Note that topics are also removed from any task using the topics.