The Appkit Workflow module can be used to apply custom business logic during the search/response/render lifecycle. Workflow Processors are designed to intercept any Appkit model object, and for example, modify a Query before it is submitted to a Platform or augment a Response before it is rendered.

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Developing Processors

All processors implement the Processor interface, parameterized with the object they are designed to work with: 
public class AcmeProcessor implements Processor<Query> {
    public void init() {
        ...
    }
    public void process(Query query) {
        ...
    }
    public void done() {
        ...
    }
}
Or: 
public class AcmeProcessor implements Processor<Response> {
    public void process(Response response) {
        ...
    }
}
Processors also support the change(T obj) method which will let you substitute model objects: public Response change(Response response);
If you extend an AbstractProcessor class then change() is automatically named by the process() method making it sufficient to implement the former.
A number of abstract helper classes make it easier to implement processors for a given purpose, such as:
  • twigkit.processor.AbstractProcessor<T> Provides abstract implementations of init() and done() and handles setting parameters.
  • twigkit.search.processors.AbstractResultProcessor Makes it easy to implement processors for Results by taking care of the iterations
    public void processResult(int index, Result result) {…​}
  • twigkit.search.processors.AbstractNamedFieldProcessor Makes it easy to implement processors that target specific fields. Requires the fields parameter (use * for all fields). Only the named fields will be passed on to the process method.
    public void process(Field field) {…​}
  • twigkit.search.processors.AbstractNamedFieldValueProcessor<T> Use this abstract class to implement a Processor that will pass the named field values (where the value is an instance of T). Requires the fields parameter (use * for all fields). Validation of the field value being of the correct type is done by the abstract class.
    public Value<String> processValue(Value<String> value) {…​}
  • twigkit.search.processors.AbstractNamedFacetProcessor Use this abstract class to implement Processor that will process specific named facets. Requires the facetNames parameter (use * for all facets).
    public void processFacet(Facet facet) {…​}
  • twigkit.search.processors.AbstractNamedFacetFiltersProcessor Use this abstract class to process all the FacetFilters in the named facets. Requires the facetNames parameter (use * for all facets).
    public void processFilter(FacetFilter filter) {…​}