How should i check if gravatar exist?

Question

using this gem https://github.com/sinisterchipmunk/gravatar how do i check if gravatar for specified email exist or not? I think i am missing some force default option? Because this

url = Gravatar.new("[email protected]").image_url

always return a picture

Midwinter

Have you tried with an invalid email address other than [email protected] ? – Gyronny

yeah, i tried, same result :-( – Midwinter

Answer 1

Looking at that gem's documentation, it sounds like you need an API key before you can run the exists method:

Fine, but how about the rest of the API as advertised at en.gravatar.com/site/implement/xmlrpc? Well, for that you need either the user’s Gravatar password, or their API key:

api = Gravatar.new("[email protected]", :api_key => "AbCdEfG1234")

api.exists?("[email protected]") #=> true or false, depending on whether the specified email exists.

If the user doesn't have a gravatar, an image will be generated for them based on the email (at least that has been my experience). I've used the gem gravatar_image_tag - http://rubygems.org/gems/gravatar_image_tag which lets you change the default gravatar image.

Inherit

This is maybe another approach to try: #2104120 – Inherit

well, i just did not catch the politics gem vs gravatar. As in written in gravatar documentation u can easy pass d= parameter to an image request: 404: do not load any image if none is associated with the email hash, instead return an HTTP 404 (File Not Found) response. That i was looking for in the mentioned gem – Midwinter

Answer 2

In case people would like to know how to do it without any gems :

The trick is to get gravatar image with a false default image and then check header response. It's achieved with the Net::HTTP ruby library.

require 'net/http'

def gravatar?(user)
    gravatar_check = "http://gravatar.com/avatar/#{Digest::MD5.hexdigest(user.gravatar_email.downcase)}.png?d=404"
    uri = URI.parse(gravatar_check)
    http = Net::HTTP.new(uri.host, uri.port)
    request = Net::HTTP::Get.new(uri.request_uri)
    response = http.request(request)
    response.code.to_i != 404 # from d=404 parameter
end

Gametogenesis

But if email doesn't exists, it doesn't reply with 404, but with the default gravatar, so how could you return false? – Chaco

Yes, that's exactly what allows you to get an error if there is no gravatar, because you provide a false default picture. – Knap

@ Noémien Kocher This works great for me on localhost, but when I deploy to Heroku, I get the error 'uninitialized constant Net::HTTP' Does anyone know why? – Blaubok

@TomD did you try to add "require 'net/http'" at the top of your file ? – Knap

@ Noémien Kocher. No, I hadn't done that, and adding it as you suggest resolved the issue. Many thanks! – Blaubok

also start with require 'digest' – Aldas

Answer 3

if (response.code.to_i == 404)
  return false
else
  return true
end

Instead of whole block, use only this(as a last line):

response.code.to_i != 404

Lipfert