Enforcing context model based policies with forward chaining

A method for enforcing a number of context model-based policies with forward chaining comprising:

• obtaining a context model by establishing inter-document references for a set of documents in XML format, the context model comprising a number of documents in XML Schema Definition Language;
• generating a set of policies, each policy based on the context model, each policy including a condition part and an action part;
• generating an instantiated context model by replacing a number of the documents of the context model in the XML Schema Definition Language with a corresponding XML instance document conforming to an XML Schema Definition of the context model such that the instantiated context model is an instance of the context model, the instantiated context model comprising instance documents, wherein said instance documents are in XML format;
• sequentially applying each policy in the set of policies to the instantiated context model;
• for each policy, determining whether the instantiated context model should be updated and, where determined that the instantiated context model should be updated, executing an updating operation;
• and
• after each updating operation, detecting and resolving any conflict created by the updating operation;
• wherein each updating operation produces a new instantiated context model to which a next policy in the set of policies is then applied.

A computer-implemented policy engine for enforcing a number of context model-based policies with forward chaining, the policy engine comprising:

• at least one processor;
• and
• a memory communicatively coupled to said at least one processor, said memory storing machine-executable instructions that, when executed by said at least one processor, cause said at least one processor to implement:
• a policy application device that applies a policy set including a plurality of policies to an instantiated context model with forward chaining as the plurality of policies in the policy set are applied, the instantiated context model comprising a set of referenced instance documents in XML format, the set of referenced instance documents comprising inter-document references among the instance documents within the set of referenced instance documents, wherein the instantiated context model is derived by replacing at least one document in an abstract context model with a corresponding instance document;
• an updating determining module that determines whether the instantiated context model should be updated;
• an updating module to:
• execute an updating operation;
• and
• a confliction detecting and resolving module that detects and resolves a confliction caused by the updating operation;
• a context model regenerator to re-generates a new instantiated context model according to the updated instance documents and the instantiated context model,
• wherein the new instantiated context model is provided to the policy application device and the policy application device applies the policy set to the new instantiated context model;
• and
• wherein the policies include a condition part and an action part;
• and
• wherein the policy application device comprises:
• a document validating unit that validates whether any instance document in the instantiated context model enables the condition part of the policy to be met by using each of the plurality of policies;
• a validation report generating unit that generates a validation report when the condition part of the policy is met;
• and
• an action enforcing unit that enforces the action part of the policy according to the validation report.