Checking if a place is within an itinerary

1# Checks whether a place has been added to an itinerary, for creating a button
2# state on an "Add to Itinerary" button. If a result is returned, you may then
3# want to indicate to the user it is already present in their itinerary, or
4# offer them to remove it. You can pass the matching itinerary location ID that
5# has this place associated from this query to the deleteItineraryItem operation
6
7query CheckItineraryPlacePresent {
8  # Use the itinerary query, supplying the itinerary ID to check
9  itinerary(id: "itinerary/ABC123") {
10    # Query the descendants, providing some constraints
11    descendants(
12      # Provide the place identifiers to check
13      placeIds: ["place/123"]
14      # You may support adding a place multiple times, but for most reading
15      # back one will be enough
16      first: 1
17    ) {
18      nodes {
19        # Obtain the ID, so we can remove this location using the operation
20        # deleteItineraryItem() to remove the item from the itinerary.
21        id
22      }
23      # Total Count should be greater than 0, as the place could be added more
24      # than once to an itinerary
25      totalCount
26    }
27  }
28}