Order of returned entities in IBM Watson Conversation service

Question

I want to create a node in the dialog that can detect airport_from and airport_to from a sentence:

"I want to go from Paris Orly to London heathrow"

This should give me both values London Heathrow and Paris Orly as an entity @airport using the indexes like this:

{
"context": {
"from": "@airport[0]",
"to": "@airport[1]"
},
"output": {
"text": {
  "values": [
    "you are going from @airport[0] to @airport[1]"
  ],
  "selection_policy": "sequential"
}
}
} 

Typicaly you would have:

@airport[0] = 'Paris Orly'
@airport[1] = 'London Heathrow' 

That works fine, but the problem is when you invert the two airports you get exatly the same result as before (ie @airport[0] = 'Paris Orly' ) and not the inverse.

What I need is getting these entities in the same order as they are in the sentence. Any ideas folks ?

Answer 1

You could use a ternary operator in the response. It is linked on the Watson Conversation expression language :

<? entities['airport'][0].location[0]<entities['airport'][1].location[0] ? 
'First, then second' : 'Second comes first' ?>

The above evaluates the first expression and if true uses the expression after the ? , if false the expression after the : .

Answer 2

I found a way to do it, you'll have to test the location of the entities and create separate answers (as many as you need).:

I am still hoping for a better approach.

Answer 3

A simple way is to create 2 entities. "From City" and "To City" and add same values in both like in "From City" add From London ,From Newyork and in "To City" add To London,To Newyork. This is a better way.