ObserverTutorial

Creating and integrating a new observer

The goal of this tutorial is to demonstrate how to develop a new observer for Unicorn.

The tutorial will focus on a service that performs simple arithmetic operations.

The observer will only accept URLs to documents described as follows:

• Mime-Type: text/plain
• Format:
  • • one expression per line
    • An expression is composed of numbers, simple operators (+,-,*,/) and brackets, that can be combined using the regular arithmetic grammar

Example:

For each line of this document, the observer will evaluate and return the result or throw an error.

Observer can take one optional parameter to multiply results by 2.

Table of contents

 1. [wiki:ObserverTutorial/WebService Write the webservice]
 1. [wiki:ObserverTutorial/Output Adapt the webservice's output]
 1. [wiki:ObserverTutorial/Contract Write the contract file]