This brief tutorial shows you an easy way to use CSIP services. Postman, a chrome extension to exercise RESTful services is used in this document. Postman is a widely accessible tool with an intuitive user interface suited even for the "RESTful beginner". The CSIP manual introduces many other ways to execute CSIP services with tools such as CURL and from various programming languages. Developers most likely pick their tool of language of choice based on integration requirements.
Postman is a powerful HTTP client for testing web services. It is a Chrome application. Follow the steps as described here to first install Chrome and then Postman. Postman is available at the Chrome Webstore.
Figure 1: Postman
After successful installation, Postman should start with empty content.
Invoking a Service
Let's exercise a simple temperature conversion service. It converts a temperature value from Celsius in Fahrenheit. The service runs on a local machine.
First, select the POST method in Postman as required by the CSIP specification to execute a service. Next, provide the service URL to the appropriate field. You will find many other, more useful endpoints of various services in this project.
The request payload is provided as the Body of this HTTP/POST request. Select raw as input type and select JSON (application/json) from the drop down list. Finally, paste or type in the JSON request content in the text field below.
Figure 2: Creating a CSIP request in Postman
The structure of a JSON CSIP request is discussed in the CSIP manual. In this example, a simple temperature value of 25 Grad C is provided. There is no metadata passed into the service.
These are all the required steps for a basic CSIP service call. More complex calls might require attaching input files which can also be done using the Postman UI. However, this simple example does not require any extra input. Finally, hit the blue Send button to execute the service.
Figure 3 shows the result of the service call. You might need to scroll to the bottom of the window.
Figure 3: Service Result
The service response as shown in the Body is also in JSON format. On successful execution, the response status is set to Finished. Service metainfo is provided about the service call. You find the result in the received payload, along with the request parameter.