I want to invoke a webservice within watson-conversation response and display the returned result from webservice to client.
For example, if I ask watson this question: how about the weather in New York 2016-12-30 ?
then watson will invoke a weather related webservice and pass the parameters city(New York) and date(2016-12-30) to the webservice, the webservice will return message "It is sunny, temperature is 30".
The client will get "It is sunny, temperature is 30" as the answer.
You might want to checkout the weather bot built with Watson Conversation and the Weather API. https://github.com/watson-developer-cloud/text-bot