scrambls>developer>Main>DeveloperReference>PolicyInterface

External Policy Interface

Scrambls policy can be configured to reference an external server. This allows the owner of a group to divert policy decisions to his or her own server. When a user tries to view a post configured with such a policy, scrambls makes a real-time request to the server has group owner has specified. The request can be contain attribute tokens that scrambls will populate from the current context. The external server is responsible for responding with a boolean that determines whether the policy term is satisfied or not.

External Policy Interface

Creating a Group Policy with an External Server Term

From the scrambls logged-in home page select Define Groups
Click Define New Group
Click Add New Rule
In the rule dialog select the rule type Validate with External Service
In the entry field that appear type in the fully qualified URL to be called along with any parameters
Save the rule, give the group a name and save it.

Post Protocol

Scrambls issues an HTTP "GET" request with the given URL. The external server should be configured to conduct the conversation over SSL, but this is not required. The response header should identify the content as: application/json.

The response is a JSON structure containing the following attributes:

name	type	description
item	string
inlist	boolean	set to true if the test is satisfied indicating to scrambls that this policy term has passed
cache	integer	determines the length in time, in seconds, that this response may be cached by scrambls. If set to 0, scrambls will not cache the response and will reach out to the external server on every request

Scrambls Attribute Tokens

Scrambls attribute tokens allow you to configure the URL of your policy test with information from the current context. Currently only one attribute is supported, email address. Other attributes and identifiers will become available over time.

Token	Description
$(email)	any instance of '$(email)' in the server URL will be replaced with the email address of the user requesting access

Examples

The following url configured as an external service will post a request to inlist on policy.myserver.com along with the paramter email

http://policy.myserver.com/TestPolicy/inlist?email=$(email)

If the current user is, say [email protected], then the call received by the external server from scrambls would be

http://policy.myserver.com/TestPolicy/[email protected]

The server configures it's response in JSON, and assuming [email protected] is to be granted access, returns:

{"item":"[email protected]","inlist":true,"cache":0}

Sample Code