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 * The contents of this file are subject to the Mozilla Public License Version
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 * The Original Code is Mozilla Communicator client code.
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 * The Initial Developer of the Original Code is
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#ifndef nsRDFTestNode_h__
#define nsRDFTestNode_h__

#include "nsRuleNetwork.h"

class nsIRDFResource;
class nsIRDFNode;

/**
 * An abstract base class for all of the RDF-related tests. This interface
 * allows us to iterate over all of the RDF tests to find the one in the
 * network that is apropos for a newly-added assertion.
 */
class nsRDFTestNode : public TestNode
{
public:
    nsRDFTestNode(TestNode* aParent)
        : TestNode(aParent) {}

    /**
     * Determine whether the node can propagate an assertion
     * with the specified source, property, and target. If the
     * assertion can be propagated, aInitialBindings will be
     * initialized with appropriate variable-to-value assignments
     * to allow the rule network to start a constrain and propagate
     * search from this node in the network.
     *
     * @return PR_TRUE if the node can propagate the specified
     * assertion.
     */
    virtual PRBool CanPropagate(nsIRDFResource* aSource,
                                nsIRDFResource* aProperty,
                                nsIRDFNode* aTarget,
                                Instantiation& aInitialBindings) const = 0;

    /**
     *
     */
    virtual void Retract(nsIRDFResource* aSource,
                         nsIRDFResource* aProperty,
                         nsIRDFNode* aTarget) const = 0;
};

#endif // nsRDFTestNode_h__
