User-agent Assign Role

This module will assign a role to an anonymous user if the HTTP_USER_AGENT is one of a specified set of values.

Use Cases

When the URL is pasted into the share textbox on Facebook, the page will be scraped for content and images. If the page is unpublished or protected, Facebook will cache an error page and this error page will be displayed for future shares. This condition persists unless manually rescraped.

The Facebook bot can be identified by HTTP_USER_AGENT and IP address range. This module enables Drupal to assign a user role based on these identifiers. This role could then be used to show unpublished content using View Unpublished.

Another use case would be to assign a specific role to visitors with Internet Explorer 6.

Limitations

This module only allows a single assignment of a role. It will not assign one role to User-agent "A" and a different role to User-agent "B".

Cautions

This module allows you to assign higher privileges to anonymous users based on user-agent—something that is possible to falsify.

To be safe:

• Restrict by IP address range, if possible.
• Add only the bare minimum of additional privileges—add one role for use with this module.
• Do not add any privileges that would allow editing content or performing admin functions.