Creating a Handler Class

A query handler is a Java class that retrieves items from the Content Engine using search criteria entered into a Data Source query form. A query handler must:

• Extend com.escenic.framework.datasource.fetcher.impl.AbstractFetcher

• Override its fetch() method

The following example shows a skeleton handler class definition:

package com.mycompany.datasource.query.handler;

import com.escenic.framework.datasource.fetcher.impl.AbstractFetcher;
import com.escenic.framework.datasource.ContextInfo;
import com.escenic.framework.datasource.model.SourceDefinition;
import com.escenic.framework.datasource.model.SourceSettings;

import java.util.List;

public class MyQueryHandler extends AbstractFetcher {

  @Override
  public List<ResultItem> fetch(final SourceDefinition pSourceDefinition,
                                final SourceSettings pSettings,
                                final ContextInfo pContextInfo) {

    // your code here

  }
}

The fetch() method's first parameter is a com.escenic.framework.datasource.model.SourceDefinition object. This object is a bean containing all the values set by the user in the query tab. It has a set of getXxx() methods for recovering various predefined standard query parameters (getSection() and getContentTypes(), for example), plus a getFields() method that returns a map containing all other custom parameters that you may have defined for your query form. The query form (and therefore the contents of the SourceDefinition bean) are determined by the query type definition (see Creating a Query Type Definition).

Once you have a created a query handler class, you need to:

• Create .properties files to register the handler class in the system

• Package the handler in a JAR file

• Deploy the JAR file in your publication