Objective-C
Objective-C
Facebook Download all Photos to Local Files
See more Facebook Examples
Demonstrates how to download all of one's Facebook photos to a local filesystem directory. This sample code keeps a local cache to avoid re-downloading the same photos twice. The program can be run again after a time, and it will download only photos that haven't yet been downloaded.Chilkat Objective-C Downloads
#import <CkoCache.h>
#import <CkoOAuth2.h>
#import <CkoRest.h>
#import <NSString.h>
#import <CkoJsonObject.h>
#import <CkoStringArray.h>
#import <CkoStringBuilder.h>
#import <CkoHttp.h>
#import <CkoFileAccess.h>
BOOL success = NO;
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
// This example will use a local disk cache to avoid re-fetching the same
// photo id after it's been fetched once.
CkoCache *fbCache = [[CkoCache alloc] init];
// The cache will use 1 level of 256 sub-directories.
fbCache.Level = [NSNumber numberWithInt:1];
// Use a directory path that makes sense on your operating system..
[fbCache AddRoot: @"C:/fbCache"];
// This example assumes a previously obtained an access token
CkoOAuth2 *oauth2 = [[CkoOAuth2 alloc] init];
oauth2.AccessToken = @"FACEBOOK-ACCESS-TOKEN";
CkoRest *rest = [[CkoRest alloc] init];
// Connect to Facebook.
success = [rest Connect: @"graph.facebook.com" port: [NSNumber numberWithInt: 443] tls: YES autoReconnect: YES];
if (success != YES) {
NSLog(@"%@",rest.LastErrorText);
return;
}
// Provide the authentication credentials (i.e. the access key)
[rest SetAuthOAuth2: oauth2];
// There are two choices:
// We can choose to download the photos the person is tagged in or has uploaded
// by setting type to "tagged" or "uploaded".
[rest AddQueryParam: @"type" value: @"uploaded"];
// To download all photos, we begin with an outer loop that iterates over
// the list of photo nodes in pages. Each page returned contains a list of
// photo node ids. Each photo node id must be retrieved to get the download URL(s)
// of the actual image.
// I don't know the max limit for the number of records that can be downloaded at once.
[rest AddQueryParam: @"limit" value: @"100"];
// Get the 1st page of photos ids.
// See https://developers.facebook.com/docs/graph-api/reference/user/photos/ for more information.
NSString *responseJson = [rest FullRequestNoBody: @"GET" uriPath: @"/v2.7/me/photos"];
if (rest.LastMethodSuccess != YES) {
NSLog(@"%@",rest.LastErrorText);
return;
}
CkoJsonObject *photoJson = [[CkoJsonObject alloc] init];
CkoStringArray *saPhotoUrls = [[CkoStringArray alloc] init];
CkoStringBuilder *sbPhotoIdPath = [[CkoStringBuilder alloc] init];
CkoJsonObject *json = [[CkoJsonObject alloc] init];
json.EmitCompact = NO;
[json Load: responseJson];
int i;
NSString *photoId = 0;
NSString *imageUrl = 0;
// Get the "after" cursor.
NSString *afterCursor = [json StringOf: @"paging.cursors.after"];
while (json.LastMethodSuccess == YES) {
NSLog(@"%@",@"-------------------");
NSLog(@"%@%@",@"afterCursor = ",afterCursor);
// For each photo id in this page...
i = 0;
int numItems = [[json SizeOfArray: @"data"] intValue];
while (i < numItems) {
json.I = [NSNumber numberWithInt: i];
photoId = [json StringOf: @"data[i].id"];
NSLog(@"%@%@",@"photoId = ",photoId);
// We need to fetch the JSON for this photo. Check to see if it's in the local disk cache,
// and if not, then get it from Facebook.
NSString *photoJsonStr = [fbCache FetchText: photoId];
if (fbCache.LastMethodSuccess == NO) {
// It's not locally available, so get it from Facebook..
[sbPhotoIdPath Clear];
[sbPhotoIdPath Append: @"/v2.7/"];
[sbPhotoIdPath Append: photoId];
[rest ClearAllQueryParams];
[rest AddQueryParam: @"fields" value: @"id,album,images"];
NSLog(@"%@",@"Fetching photo node from Facebook...");
// This REST request will continue using the existing connection.
// If the connection was closed, it will automatically reconnect to send the request.
photoJsonStr = [rest FullRequestNoBody: @"GET" uriPath: [sbPhotoIdPath GetAsString]];
if (rest.LastMethodSuccess != YES) {
NSLog(@"%@",rest.LastErrorText);
return;
}
// Add the photo JSON to the local cache.
[fbCache SaveTextNoExpire: photoId eTag: @"" strData: photoJsonStr];
}
// Parse the photo JSON and add the main photo download URL to saPhotoUrls
// There may be multiple URLs in the images array, but the 1st one is the largest and main photo URL.
// The others are smaller sizes of the same photo.
[photoJson Load: photoJsonStr];
imageUrl = [photoJson StringOf: @"images[0].source"];
if (photoJson.LastMethodSuccess == YES) {
// Actually, we'll add a small JSON document that contains both the image ID and the URL.
CkoJsonObject *imgUrlJson = [[CkoJsonObject alloc] init];
[imgUrlJson AppendString: @"id" value: photoId];
[imgUrlJson AppendString: @"url" value: imageUrl];
[saPhotoUrls Append: [imgUrlJson Emit]];
NSLog(@"%@%@",@"imageUrl = ",imageUrl);
}
i = i + 1;
}
// Prepare for getting the next page of photos ids.
// We can continue using the same REST object.
// If already connected, we'll continue using the existing connection.
// Otherwise, a new connection will automatically be made if needed.
[rest ClearAllQueryParams];
[rest AddQueryParam: @"type" value: @"uploaded"];
[rest AddQueryParam: @"limit" value: @"20"];
[rest AddQueryParam: @"after" value: afterCursor];
// Get the next page of photo ids.
responseJson = [rest FullRequestNoBody: @"GET" uriPath: @"/v2.7/me/photos"];
if (rest.LastMethodSuccess != YES) {
NSLog(@"%@",rest.LastErrorText);
return;
}
[json Load: responseJson];
afterCursor = [json StringOf: @"paging.cursors.after"];
}
NSLog(@"%@",@"No more pages of photos.");
// Now iterate over the photo URLs and download each to a file.
// We can use Chilkat HTTP. No Facebook authorization (access token) is required to download
// the photo once the URL is known.
CkoHttp *http = [[CkoHttp alloc] init];
// We'll cache the image data so that if run again, we don't re-download the same image again.
int numUrls = [saPhotoUrls.Count intValue];
i = 0;
CkoJsonObject *urlJson = [[CkoJsonObject alloc] init];
NSData imageBytes;
CkoFileAccess *fac = [[CkoFileAccess alloc] init];
while (i < numUrls) {
[urlJson Load: [saPhotoUrls GetString: [NSNumber numberWithInt: i]]];
photoId = [urlJson StringOf: @"id"];
imageUrl = [urlJson StringOf: @"url"];
// Check the local cache for the image data.
// Only download and save if not already cached.
imageBytes = [fbCache FetchFromCache: imageUrl];
if (fbCache.LastMethodSuccess == NO) {
// This photo needs to be downloaded.
CkoStringBuilder *sbImageUrl = [[CkoStringBuilder alloc] init];
[sbImageUrl Append: imageUrl];
// Let's form a filename..
NSString *extension = @".jpg";
if ([sbImageUrl Contains: @".gif" caseSensitive: NO] == YES) {
extension = @".gif";
}
if ([sbImageUrl Contains: @".png" caseSensitive: NO] == YES) {
extension = @".png";
}
if ([sbImageUrl Contains: @".tiff" caseSensitive: NO] == YES) {
extension = @".tiff";
}
if ([sbImageUrl Contains: @".bmp" caseSensitive: NO] == YES) {
extension = @".bmp";
}
CkoStringBuilder *sbLocalFilePath = [[CkoStringBuilder alloc] init];
[sbLocalFilePath Append: @"C:/Photos/facebook/uploaded/"];
[sbLocalFilePath Append: photoId];
[sbLocalFilePath Append: extension];
imageBytes = [http QuickGet: imageUrl];
if (http.LastMethodSuccess != YES) {
NSLog(@"%@",http.LastErrorText);
return;
}
// We've downloaded the photo image bytes into memory.
// Save it to the cache AND save it to the output file.
[fbCache SaveToCacheNoExpire: imageUrl eTag: @"" data: imageBytes];
[fac WriteEntireFile: [sbLocalFilePath GetAsString] fileData: imageBytes];
NSLog(@"%@%@",@"Downloaded to ",[sbLocalFilePath GetAsString]);
}
i = i + 1;
}
NSLog(@"%@",@"Finished downloading all Facebook photos!");