(Ruby) Download Photo to a File

Assuming we have the ID of a Photo, this example demonstrates how to download the photo image data to a file.

Chilkat Ruby Downloads Ruby Library for Linux and MAC OS X

require 'chilkat'

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

# This example assumes a previously obtained an access token
oauth2 = Chilkat::CkOAuth2.new()
oauth2.put_AccessToken("FACEBOOK-ACCESS-TOKEN")

rest = Chilkat::CkRest.new()

# Connect to Facebook...
success = rest.Connect("graph.facebook.com",443,true,true)
if (success != true)
    print rest.lastErrorText() + "\n";
    exit
end

# Provide the authentication credentials (i.e. the access key)
rest.SetAuthOAuth2(oauth2)

# Assumes we've already obtained a Photo ID.
photoId = "10210199026347451"

sbPath = Chilkat::CkStringBuilder.new()
sbPath.Append("/v2.7/")
sbPath.Append(photoId)

# First we're going to get the photo informaton so we can get the URL of the image file data.
# Select the fields we want.
# See https://developers.facebook.com/docs/graph-api/reference/photo/
rest.AddQueryParam("fields","id,album,images")

responseJson = rest.fullRequestNoBody("GET",sbPath.getAsString())
if (rest.get_LastMethodSuccess() != true)
    print rest.lastErrorText() + "\n";
    exit
end

json = Chilkat::CkJsonObject.new()
json.put_EmitCompact(false)
json.Load(responseJson)

# Show the JSON in human-readable format.
print json.emit() + "\n";

# Get the image URL.
imageUrl = json.stringOf("images[0].source")
print "Downloading from " + imageUrl + "\n";

sbImageUrl = Chilkat::CkStringBuilder.new()
sbImageUrl.Append(imageUrl)

# Build the output local file path.
sbToPath = Chilkat::CkStringBuilder.new()
sbToPath.Append("qa_output/fb")
sbToPath.Append(json.stringOf("id"))
bCaseSensitive = false
if (sbImageUrl.Contains(".jpg",bCaseSensitive) == true)
    sbToPath.Append(".jpg")
else
    sbToPath.Append(".png")
end

print "Downloading to " + sbToPath.getAsString() + "\n";

# Download using Chilkat HTTP.
http = Chilkat::CkHttp.new()
success = http.Download(imageUrl,sbToPath.getAsString())
if (success != true)
    print http.lastErrorText() + "\n";
else
    print "Downloaded." + "\n";
end