SerializableMessageFilter.java

package com.netflix.suro.routing.filter;

/**
 * An optional feature for a {@link MessageFilter} which indicates that the event filter can be converted back and forth
 * from a string. <br/>
 * Typically, if the filter is an expression of a language, as defined by {@link com.netflix.suro.routing.filter.lang}, then
 * it should implement this interface. On the other hand, if the filter is represented as code, implementation of this
 * interface is not required. <br/>
 * Any persistence of an {@link MessageFilter} will require the filter to implement this interface, else it will not be
 * persisted. Since, the filters created in code will typically be registered by the subscribers themselves, they
 * typically will not need any persistence. <br/>
 * One will notice that this filter only supports converting the object representation to a string and not back as the
 * conversion from arbitrary string is handled by {@link MessageFilterCompiler}. Such, factory
 * kind of methods are deliberately not provided here so that the filter classes do not have to provide any parsing
 * logic.
 *
 * @author Nitesh Kant (nkant@netflix.com)
 */
public interface SerializableMessageFilter extends MessageFilter {

    /**
     * Serializes this filter into the filter string
     *
     * @return String representation of the filter.
     */
    String serialize();
}