How to post an image to a Facebook wall using Grails - facebook

Question

I am using the grails facebook-sdk plugin to connect and post to facebook.
To publish a message to a user's wall I use:
def publishMessageResponse = facebookClient.publish("me/feed", [message:"RestFB test"])
This works fine, but I want to post an image to a specific album of the user. The documentation says that it should work with:
def publishPhotoResponse = facebookClient.publishFile("me/photos", [message, "Test cat"], "/cat.png")
But I alway get a "File not found" error. The image I have is stored in a data base and can be retrieved by getting the url to the image.
Knowing the url of the image, how can I post this image to a specific user photo album? How can I create a new Album?

Answer 1

I haven't used the facebook-sdk but I would assume that the issue is that it can't find the file '/cat.png' relative to the location of you're project. You'll need to provide valid and accessible file path.
You could confirm this by doing something like this before publishFile...
assert new File("/cat.png").exists(), "File does not exist!"
UPDATE:
Here is an example of converting a url to a file. This may not be the ideal solution if there are other options besides using an actual file.
def someUrl = "http://www.google.com/images/logo.gif";
def file = File.createTempFile("facebookUpload",".temp").withOutputStream { out ->
out << new URL(someUrl).openStream()
}
file.deleteOnExit();
def publishPhotoResponse = facebookClient.publishFile("me/photos", [message, "Test cat"], file)