I am working on Google API like chat, contacts and so on...
I am stuck on developer_key
as mentioned in gdata doc.
You can get this at https://code.goog
Go to https://code.google.com/p/google-api-php-client/wiki/OAuth2
Scroll down to where it says 'Visit the Google API Console to generate your developer key, OAuth2 client id, OAuth2 client secret, and register your OAuth2 redirect uri. Copy their values since your will need to input them in your application.'
Click on the 'Google API Console' link.
When it pops up and says 'Welcome to the new Google Developers Console! Prefer the old console? Go back | Dismiss' Click on 'GO BACK'