Writing a Query Modifier

Writing a QM is very much like writing a new Data Provider. The only difference is you import a different set of interfaces. Follow the documentation for creating a Data Provider and create a new plugin project.

Edit MANIFEST entries

After creating a brand new project, $PROJECT_HOME/META-INF/MANIFEST.MF must be modified to import packages that are required by this project to develop a QM. These packages are as follows.

 

Import-Package: com.google.gson;version="2.1.0",

 com.google.gson.annotations;version="2.1.0",

 com.google.gson.internal;version="2.1.0",

 com.google.gson.internal.bind;version="2.1.0",

 com.google.gson.reflect;version="2.1.0",

 com.google.gson.stream;version="2.1.0",

 edu.emory.cci.bindaas.framework.api,

 edu.emory.cci.bindaas.framework.event,

 edu.emory.cci.bindaas.framework.event.listeners,

 edu.emory.cci.bindaas.framework.model,

 edu.emory.cci.bindaas.framework.provider.exception,

 edu.emory.cci.bindaas.framework.util,

 org.apache.commons.logging;version="1.1.1",

 org.osgi.framework;version="1.3.0"

 

One more entry needs to be added in order to tell Bindaas where to pick-up spring configuration files :

 

Spring-Context: META-INF/spring/*.xml

Writing LoggingQM

public class LoggingQRM implements IQueryModifier{
    private Log log = LogFactory.getLog(getClass());
    @Override
    public JsonObject getDocumentation() {
        return new JsonObject();
    }
    @Override
    public void validate() throws ModifierException {
        // not implemented  
    }

    @Override
    public String getDescriptiveName() {
        return "Plugin for logging query";
    }

    @Override
    public String modifyQuery(String query, JsonObject dataSource,
            RequestContext requestContext, JsonObject modifierProperties)
            throws AbstractHttpCodeException {
        log.info("Query  intercepted [" + query + "]");
        return query;
    }
    @Override
    public Map<String, String> modiftQueryParameters(Map<String, String> queryParams, JsonObject dataSource,    RequestContext requestContext, JsonObject modifierProperties) throws AbstractHttpCodeException {
        return queryParams;
    }
}