Properly way for obtaining the N latest videos of channel : search vs playlistItem vs activities endpoints - youtube-data-api

Question

I'm developing for a web app that needs to retrieve the last 10 videos of a user(channel).
First approach
Was to use the search endpoint with param 'forMine' ordering by date, but then I figured that maybe that param could retrieve videos uploaded by the user in a diferent channel or whatever...
First result with channel ID and date - 1st Aproach
Second approach
Was to use the search endpoint with param 'channelId' ordering by date, but then I realized that descriptions were incomplete and most importantly there were some videos missing comparing with first aproach, even if the missing videos belonged to same channel (as showed in pics links)
First resutl with channel ID and date - 2nd Aproach
So, then I googled to find some solution and found other way.
Third approach
Was to use the playlistItem endpoint as I found in Google, and seemed ok (I supposed) because it returned same videos that first aproach and consumed less quota but this method left me with doubts as I didn't knew if the videos would be the latest or maybe they would be sorted by position in the playlist and couldn't be trusted to be the most recent
That said, what would be the correct way to get the N most recent videos from a channel, please?
Regardless of the quota consumption (the less quota the better, of course, but an accurate result is essential)
I'm so confussed with the API response...
Thank you so much!
-- EDITED: NEW APPROACH AND FURTHER INVESTIGATIONS --
Fourth approach
Was to use activities endpoint as was stated by #stvar in his answer. I found that this way, as on second approach, there were some videos missing comparing with first and third approaches, and it was required to retrieve everything without 'maxResults' param because there were activities not related to video upload, making mandatory to perform pagination and a self filtering by type 'upload' after retrieving response in order to get N videos (or be confident in getting N videos uploaded in first 50 retrieved items)
Self Investigations
Further investigations and tests bringed me response to the issue of 'missing videos' of some approaches.
The status of that missing videos were 'unlisted', so they were videos uploaded to the channel, property of the channel, uploaded by user of the channel... but not retrieved by some methods that seemed to retrieve only 'public' videos not 'unlisted' (hidden) nor 'private'.
NOTE: I did my test with Google API PHP Client Library, this behaviour seems not to be on 'Try this API' as it returns only 'public' items, so be careful on trust in 'Try this API' results as it seems to use some hidden filters or something...
Also I tested the channel upload playlist to verify that the order can not be changed and has a LIFO sorting
CONCLUSIONS
At this point, my self conclusion is that there is not a proper way to solve this but quite ways to do it in depend of requisites of status and amount of free quota
Search endpoint seems to work all right, if you have a good amount of unused quota (100 each call) that is the direct way and easiest one as you can sort it and filtering as needed by a bunch of params, taking care to use 'forMine' param if you need every uploaded video or 'channelId' if you need only 'listed' and 'public' ones.
PlaylistItems endpoint is a proper way if you are in a quota crisis (1 each call) as the result is sorted by recent date, taking care to do pagination and post filtering if only 'public' videos are needed till retrieve the desired amount of video ids, otherwhise you can go all the way easy.
Note that the date used to order is the upload date not the post date
(thanks to #stvar for bringing this to the attention)
Activity endpoint, also for quota crisis (1 each call), while it could be more accurate than the others if you only want public videos (it is ordered by recent 'first publish date' so not accurate 100% neither ), is for me the one that gives more work, as it retrieves activities other than 'video upload', so you can not skip pagination and post filtering to retrieve the desired amount of video ids, besides that way you only have access, as said before, to public videos (which is fine if that meets your needs).
Anyway, if you need more than 50 ids, you need to make pagination whatever the aproach you use.
Hope this help someone else and thanks so much to contributors
PS: People in charge of the YouTube API, perhaps a filter by state among some others would be interesting, Thanks!!!

Answer 1

You may employ the Activities.list API endpoint, queried with:
mine=true,
part=snippet,contentDetails,
fields=items(snippet(type),contentDetails(upload)), and
maxResults=50.
For to obtain your desired N uploads, you have to implement pagination. That is that you have to successively call the endpoint until you reach N result set items that have snippet.type equal with upload.
Note that you may well use channelId=CHANNEL_ID instead of mine=true, if you're interested about the most recent uploads of a channel identified by its ID CHANNEL_ID rather than your own channel.
According to the docs, you'll get from this endpoint a result set made of Activities resource items that will contain the following info:
contentDetails.upload (object)
The upload object contains information about the uploaded video. This property is only present if the snippet.type is upload.
contentDetails.upload.videoId (string)
The ID that YouTube uses to uniquely identify the uploaded video.
The official docs state that each call to Activities.list endpoint has a quota cost of one unit.
Futhermore, upon obtaining a set of video IDs, you may invoke the Videos.list endpoint with a properly assigned id parameter, for to obtain from the endpoint all the details you need for each and every video of your interest.
Note that if you have a set of video IDs of cardinality K, since the parameter id of Videos.list endpoint can be specified as a comma-separated list of video IDs, then you may reduce the number of calls to Videos.list endpoint from K to floor(K / 50) + (K % 50 ? 1 : 0) by appropriately using the feature of id just mentioned.
According to the official docs, each call to Videos.list endpoint has also a quota cost of one unit.
Clarifications upon OP's request:
Question no. 1: The Activities.list endpoint produces only the activities specified by the Activities resource. The type property enumerates them all:
snippet.type (string)
The type of activity that the resource describes.
Valid values for this property are: channelItem, comment (not currently returned), favorite, like, playlistItem, promotedItem, recommendation, social, subscription, upload, bulletin (deprecated).
Indeed your remark is correct. For example, when getting the most recent 10 uploads, is possible that you'll have to scan a number of pages P of result sets, with P >= 2, until you reached collecting the desired 10 upload items. (Actual tests have confirmed me this to be factual.)
Question no. 2: The Activities.list endpoint produces items that are sorted by publishedAt; just replace the above fields with:
fields=items(snippet(type,publishedAt),contentDetails(upload))
and see that for yourself.
I could make here the following argument justifying the necessity that the items resulted upon the invocation of Activities.list endpoint be ordered chronologically by publishedAt (the newest first). One may note that, indeed, the official docs quoted above do not specify explicitly that ordering condition I just mentioned; but bare with me for a while:
My argument is of a pragmatic kind: if the result set of Activities.list is not ordered as mentioned, then this endpoint becomes useless. This is so, since, in this case, for one to obtain the most recent upload activity would have to fetch locally all the upload activities, for to then scan that result set for the most recent one. Being compelled to fetch all upload activities only for to obtain the newest one is pragmatically a nonsense. Therefore, by way of contradiction, the result set has to be ordered chronologically by publishedAt with the newest being the first.
Question no. 3: Indeed Search.list is not precise -- it has a fuzzy behavior. I can confirm this based on my own experience; but, unfortunately, I cannot point you to official docs (from Google or YouTube) that acknowledge and explain this behavior. As unfortunate as it is, for its users Search.list is completely opaque.
On the other hand, Activities.list is precise -- it has to be like that; if it wouldn't be precise, then that's a serious bug in the implementation (in my educated opinion).