get dropbox thumbnails with getThumbnailBatch - ios

Question

I'm using the dropbox objc API and I'm trying to get all thumbnails in a specific dropbox folder.
But I'm completely stuck at DBFILESGetThumbnailBatchArg. How do I initiate paths to all images in a folder?
This is the line I'm stuck at:
[[client.filesRoutes getThumbnailBatch:<#(nonnull NSArray<DBFILESThumbnailArg *> *)#>]
setResponseBlock:^(
DBFILESGetThumbnailBatchResult * _Nullable result,
DBFILESGetThumbnailBatchError * _Nullable routeError,
DBRequestError * _Nullable networkError) { etc etc..
Documentation says
DBFILESThumbnailArg *arg = [[DBFILESThumbnailArg alloc] initWithPath:<#(nonnull NSString *)#>];
DBFILESGetThumbnailBatchArg *batchArg = [[DBFILESGetThumbnailBatchArg alloc]
initWithEntries:<#(nonnull NSArray<DBFILESThumbnailArg *> *)#>];
How do I init a list of paths of DBFILESThumbnailArg?
Link to documentation:
https://dropbox.github.io/dropbox-sdk-obj-c/api-docs/latest/Classes/DBFILESRouteObjects.html#/c:objc(cs)DBFILESRouteObjects(cm)DBFILESGetThumbnailBatch

Answer 1

As you found, the getThumbnailBatch method expects an NSArray<DBFILESThumbnailArg *>, so calling it would look like this:
NSArray<DBFILESThumbnailArg *> *entries = #[[[DBFILESThumbnailArg alloc] initWithPath:#"/test1.jpg"], [[DBFILESThumbnailArg alloc] initWithPath:#"/test2.jpg"]];
[[client.filesRoutes getThumbnailBatch:entries]
setResponseBlock:^(DBFILESGetThumbnailBatchResult *result, DBFILESGetThumbnailBatchError *routeError, DBRequestError *networkError) {
if (result) {
NSLog(#"result:");
NSLog(#"%#", result);
} else if (routeError) {
NSLog(#"routeError:");
NSLog(#"%#", routeError);
} else if (networkError) {
NSLog(#"networkError:");
NSLog(#"%#", networkError);
};
}];

Answer 2

I solved this using a NSMutableArray, posting my solution if others come looking:
//Create a temporary NSMutableArray
NSMutableArray *thumbArgMutable = [[NSMutableArray alloc] init];
for (NSString* image in _images)
{
//Create DBFILESThumbnailArg from NSString
DBFILESThumbnailArg *arg = [[DBFILESThumbnailArg alloc] initWithPath:image];
//Add path as DBFILESThumbnailArg to NSMutableArray
[thumbArgMutable addObject:arg];
}
//Copy NSMutableArray to a new DBFILESThumbnailArg
DBFILESThumbnailArg *thumbArg = [thumbArgMutable copy];
//create a DBFILESGetThumbnailBatchArg and init with the copied DBFILESThumbnailArg
DBFILESGetThumbnailBatchArg *thumbArgBatch = [[DBFILESGetThumbnailBatchArg alloc] initWithEntries:thumbArg];
DBUserClient *client = [[DBUserClient alloc] initWithAccessToken:#"TOKEN"];
//use property entries from DBFILESGetThumbnailBatchArg
[[client.filesRoutes getThumbnailBatch:thumbArgBatch.entries]
setResponseBlock:^(DBFILESGetThumbnailBatchResult * _Nullable result,
DBFILESGetThumbnailBatchError * _Nullable routeError,
DBRequestError * _Nullable networkError)
{
if (result) {
NSLog(#"%#\n", result);
//loop all downloaded thumbnails
for (DBFILESGetThumbnailBatchResultEntry *data in result.entries)
{
//extract data from each base64 encoded thumbnail string
NSData *thumbData = [[NSData alloc] initWithBase64EncodedString:data.success.thumbnail options:0];
//create UIImage from data
UIImage *thumbImage = [UIImage imageWithData:thumbData];
}
}
else { //if download failed
NSLog(#"%#\n%#\n", routeError, networkError);
}