Getting status for playlist from Youtube API - ios

Question

I'm building an app that based on user's choice connects to youtube api and get's list of videos of certain playlist.
I would like to make it safe to use and if the status is not 200, make it impossible for the next screen to show.
The JSON result from my request does not return any information on the status other than privacy status (similarly, if I get data for a video not a playlist I get detailed information) :
var urlString = "https://www.googleapis.com/youtube/v3/playlistItems?part=snippet&maxResults=500&playlistId=\(playlistId)&key=XXXXX"
"status":{
"privacyStatus":"public"
}
How do I verify that the request for the playlist is valid?
Thanks!

Answer 1

I have not found a reliable way to test the YT api status, so I generally will look for results from the call that should be there. And if they are not there (i.e. empty or '0' ) , then it is normally a failed call.
So [totalResults] and/or [title] as example.

Answer 2

There are two parts here.
You need to determine if the actual HTTP request was successful or not (that is the request to https://googleapis/youtube/v3/[method]?[parameters])
You have a specific requirement where you need to handle cases where there is no data. The response from the API itself will not explicitly provide this to you, instead you need to define what failure means.
With this in mind, you could implement two levels of checks:
Check 1 - HTTP status code
The first level would check the HTTP status code (200 = OK, 400 = Bad Request, etc.).
If your API request returns a status of 200, you can move on to the next level of checks (see Check 2). However, if your API request returns a status of 400, then the request has failed and no further checks are required (or necessary).
Note: If you do get a 400 status, there is some JSON in the response which contains detailed information regarding the error.
{
"error": {
"errors": [
{
"domain": "youtube.parameter",
"reason": "missingRequiredParameter",
"message": "No filter selected. Expected one of: id, playlistId",
"locationType": "parameter",
"location": ""
}
],
"code": 400,
"message": "No filter selected. Expected one of: id, playlistId"
}
}
Check 2 - Data
The second level would check to see if any results have been returned (as it seems possible to have a HTTP status code of 200 and no results).
This has nothing to do with the status of the actual HTTP request itself. Instead you have to check the response to see if the data you application requires is present or not.
With the example of a 200 response below, the items array is empty. So you could say that even though the request was successful, this is a failure condition and not show your next screen.
{
"kind": "youtube#playlistItemListResponse",
"etag": "\"[etag would appear here]\"",
"nextPageToken": "CAAQAA",
"pageInfo": {
"totalResults": 199,
"resultsPerPage": 0
},
"items": [
]
}
Note: The above is an example where the results per page was purposely set to 0.