Getting Started – REST API

Step 1

To use the OAS REST API you must first register the HTTP listener. This is done with the OAS Service Control Manager under the section labeled “HTML HMI Registration”.

Define the exclusive Node Name and Port Number  that is to be supported. The Node Name should be the registered domain name, IP address, or network node name that all clients will connect to from their browsers. If you are unsure of which node name to use, localhost will work in most cases.

NOTE: Before clicking “Register”, be sure to stop all services. If services are running, the Service Control app will prompt you to stop them.

Step 2

Start up all services, and be sure to include the Framework 4.5 Service as this houses the listener specific to the REST API.

Step 3

Test your API service.
Navigate to http://restapi.openautomationsoftware.com to open the REST API online documentation.

This documentation illustrates all of the operations available to any REST API client and can be tested using the Postman application client.  In the upper right corner of the documentation, you will see a button to Run in Postman, which will install the API documentation into the Postman client for direct execution against any OAS server.  Additionally, the documentation can be configured to display code samples in multiple languages including cURL, jQuery, and NodeJS. Feel free to browse the documentation at any time and to refer back to it while developing your applications.

Clicking Run in Postman will pop up a dialog box to import the REST API into an existing installation of Postman, or you can choose to install the app for the first time. Postman is available for Windows and Mac desktops as well as in a Chrome extension.

Once installed and the API has been downloaded into the app, you will see the following interface, with all operations on the left, organized identically to the online documentation:

The first operation to execute is the Authenticate call, which will generate a REST API session and returns a clientid and token to be used in all subsequent calls to the OAS server.

In the list of operations, expand and select Authenticate and you will see the following on the right side of the app:

This shows that the Authenticate operation is executed as an HTTP POST against the /authenticate URL appended to the base {{url}}. This base URL is defined in your Environment here. Select Manage Environments to add new fields:

Click ADD to create a new Environment which will hold environment variables:

Add a name for your environment, then add a key of url with a value of http://localhost:58725/OASREST/v2 and click ADD to create the new environment. Then return to the Authenticate operation.

Now under the Environments dropdown, select your new Environment. You should see the {{url}} turn orange, indicating that the environment variable is being used.

You can now click SEND to execute the post against your server. If successful, you should see a response body similar to the one below, containing the clientid and token fields.

You can then use these fields in the header of all other operations using the Postman app to test your server.