Zig
Zig
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 Zig Downloads
const std = @import("std");
const chilkat = @import("chilkat");
pub fn main(init: std.process.Init) !void {
const alloc = init.arena.allocator();
// 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.
const fb_cache = try chilkat.Cache.init();
defer fb_cache.deinit();
// The cache will use 1 level of 256 sub-directories.
fb_cache.setLevel(1);
// Use a directory path that makes sense on your operating system..
fb_cache.addRoot("C:/fbCache");
// This example assumes a previously obtained an access token
const oauth2 = try chilkat.OAuth2.init();
defer oauth2.deinit();
oauth2.setAccessToken("FACEBOOK-ACCESS-TOKEN");
const rest = try chilkat.Rest.init();
defer rest.deinit();
// Connect to Facebook.
rest.connect("graph.facebook.com", 443, true, true) catch {
std.debug.print("{s}\n", .{try rest.getLastErrorText(alloc)});
return;
};
// Provide the authentication credentials (i.e. the access key)
rest.setAuthOAuth2(oauth2) catch {};
// 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", "uploaded") catch {};
// 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", "100") catch {};
// Get the 1st page of photos ids.
// See https://developers.facebook.com/docs/graph-api/reference/user/photos/ for more information.
var response_json: [:0]const u8 = rest.fullRequestNoBody(alloc, "GET", "/v2.7/me/photos") catch {
std.debug.print("{s}\n", .{try rest.getLastErrorText(alloc)});
return;
};
const photo_json = try chilkat.JsonObject.init();
defer photo_json.deinit();
const sa_photo_urls = try chilkat.StringArray.init();
defer sa_photo_urls.deinit();
const sb_photo_id_path = try chilkat.StringBuilder.init();
defer sb_photo_id_path.deinit();
const json = try chilkat.JsonObject.init();
defer json.deinit();
json.setEmitCompact(false);
json.load(response_json) catch {};
var i: i32 = 0;
var photo_id: [:0]const u8 = "";
var image_url: [:0]const u8 = "";
// Get the "after" cursor.
var after_cursor: [:0]const u8 = try json.stringOf(alloc, "paging.cursors.after");
while (json.getLastMethodSuccess()) {
std.debug.print("-------------------\n", .{});
std.debug.print("afterCursor = {s}\n", .{after_cursor});
// For each photo id in this page...
i = 0;
const num_items = json.sizeOfArray("data");
while (i < num_items) {
json.setI(i);
photo_id = try json.stringOf(alloc, "data[i].id");
std.debug.print("photoId = {s}\n", .{photo_id});
// 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.
var photo_json_str: [:0]const u8 = fb_cache.fetchText(alloc, photo_id) catch "";
if (!fb_cache.getLastMethodSuccess()) {
// It's not locally available, so get it from Facebook..
sb_photo_id_path.clear();
sb_photo_id_path.append("/v2.7/") catch {};
sb_photo_id_path.append(photo_id) catch {};
rest.clearAllQueryParams() catch {};
rest.addQueryParam("fields", "id,album,images") catch {};
std.debug.print("Fetching photo node from Facebook...\n", .{});
// This REST request will continue using the existing connection.
// If the connection was closed, it will automatically reconnect to send the request.
photo_json_str = rest.fullRequestNoBody(alloc, "GET", try sb_photo_id_path.getAsString(alloc)) catch {
std.debug.print("{s}\n", .{try rest.getLastErrorText(alloc)});
return;
};
// Add the photo JSON to the local cache.
fb_cache.saveTextNoExpire(photo_id, "", photo_json_str) catch {};
}
// 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.
photo_json.load(photo_json_str) catch {};
image_url = try photo_json.stringOf(alloc, "images[0].source");
if (photo_json.getLastMethodSuccess()) {
// Actually, we'll add a small JSON document that contains both the image ID and the URL.
const img_url_json = try chilkat.JsonObject.init();
defer img_url_json.deinit();
img_url_json.appendString("id", photo_id) catch {};
img_url_json.appendString("url", image_url) catch {};
sa_photo_urls.append(try img_url_json.emit(alloc)) catch {};
std.debug.print("imageUrl = {s}\n", .{image_url});
}
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() catch {};
rest.addQueryParam("type", "uploaded") catch {};
rest.addQueryParam("limit", "20") catch {};
rest.addQueryParam("after", after_cursor) catch {};
// Get the next page of photo ids.
response_json = rest.fullRequestNoBody(alloc, "GET", "/v2.7/me/photos") catch {
std.debug.print("{s}\n", .{try rest.getLastErrorText(alloc)});
return;
};
json.load(response_json) catch {};
after_cursor = try json.stringOf(alloc, "paging.cursors.after");
}
std.debug.print("No more pages of photos.\n", .{});
// 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.
const http = try chilkat.Http.init();
defer http.deinit();
// We'll cache the image data so that if run again, we don't re-download the same image again.
const num_urls = sa_photo_urls.getCount();
i = 0;
const url_json = try chilkat.JsonObject.init();
defer url_json.deinit();
const fac = try chilkat.FileAccess.init();
defer fac.deinit();
while (i < num_urls) {
url_json.load(try sa_photo_urls.getString(alloc, i)) catch {};
photo_id = try url_json.stringOf(alloc, "id");
image_url = try url_json.stringOf(alloc, "url");
// Check the local cache for the image data.
// Only download and save if not already cached.
ERROR: Method not in the Zig package: Cache.FetchFromCache
ERROR: Method not in the Zig package: Cache.FetchFromCache
image_bytes = fb_cache.ERROR();
if (!fb_cache.getLastMethodSuccess()) {
// This photo needs to be downloaded.
const sb_image_url = try chilkat.StringBuilder.init();
defer sb_image_url.deinit();
sb_image_url.append(image_url) catch {};
// Let's form a filename..
var extension: [:0]const u8 = ".jpg";
if (sb_image_url.contains(".gif", false)) {
extension = ".gif";
}
if (sb_image_url.contains(".png", false)) {
extension = ".png";
}
if (sb_image_url.contains(".tiff", false)) {
extension = ".tiff";
}
if (sb_image_url.contains(".bmp", false)) {
extension = ".bmp";
}
const sb_local_file_path = try chilkat.StringBuilder.init();
defer sb_local_file_path.deinit();
sb_local_file_path.append("C:/Photos/facebook/uploaded/") catch {};
sb_local_file_path.append(photo_id) catch {};
sb_local_file_path.append(extension) catch {};
ERROR: Method not in the Zig package: Http.QuickGet
ERROR: Method not in the Zig package: Http.QuickGet
image_bytes = http.ERROR();
if (!http.getLastMethodSuccess()) {
std.debug.print("{s}\n", .{try http.getLastErrorText(alloc)});
return;
}
// We've downloaded the photo image bytes into memory.
// Save it to the cache AND save it to the output file.
ERROR: Method not in the Zig package: Cache.SaveToCacheNoExpire
_ = fb_cache.ERROR();
ERROR: Method not in the Zig package: FileAccess.WriteEntireFile
_ = fac.ERROR();
std.debug.print("Downloaded to {s}\n", .{try sb_local_file_path.getAsString(alloc)});
}
i = i + 1;
}
std.debug.print("Finished downloading all Facebook photos!\n", .{});
}