Nest ElasticSearch adding conditional Terms

Question

I have the following Query that I am building up, notice that filtering on the companyGroupId I cant seem to find suitable way to add and conditional Term.

I would like to check the includeTerminationDate value and conditionally add the term

So in a nutshell, if false don't return records with an termination date.

private Func<QueryContainerDescriptor<EmployeeDocument>, QueryContainer> EmployeeSearchQuery(string query, long companyGroupId, bool includeTerminationDate)
        {
            return q => q
                            .MultiMatch(m => m
                                .Query(query)

                                .Type(TextQueryType.MostFields)
                                .MinimumShouldMatch("90%")
                                .Fields(f => f
                                    .Field(ff => ff.FullName, 3)
                                    .Field(ff => ff.Number, 3)
                                    .Field(ff => ff.Email)
                                    .Field(ff => ff.JobNumber)
                                    .Field(ff => ff.Description))) && q.Term(f => f.CompanyGroupId, companyGroupId);
        }

The one why would just be to duplicate the code and add the Term per the condition. But i would like to keep to the DRY Principle. The other way would be something like the below, which I cant seem to figure out.

return q => q
                            .MultiMatch(m => m
                                .Query(query)

                                .Type(TextQueryType.MostFields)
                                .MinimumShouldMatch("90%")
                                .Fields(f => f
                                    .Field(ff => ff.FullName, 3)
                                    .Field(ff => ff.Number, 3)
                                    .Field(ff => ff.Email)
                                    .Field(ff => ff.JobNumber)
                                    .Field(ff => ff.Description))) && q.Term(f => f.CompanyGroupId, companyGroupId)
                                                                     && !includeTerminationDate ? q.Term(f => f.TerminationDate, null) : 'Otherwise do not include term';

Answer 1

One way to achieve this would be to convert the expression to a method group, and conditionally add the query

private Func<QueryContainerDescriptor<EmployeeDocument>, QueryContainer> EmployeeSearchQuery(string query, long companyGroupId, bool includeTerminationDate)
{
    return q =>
    {
        var qc = q.MultiMatch(m => m
                   .Query(query)
                   .Type(TextQueryType.MostFields)
                   .MinimumShouldMatch("90%")
                   .Fields(f => f
                       .Field(ff => ff.FullName, 3)
                       .Field(ff => ff.Number, 3)
                       .Field(ff => ff.Email)
                       .Field(ff => ff.JobNumber)
                       .Field(ff => ff.Description))) && 
                q.Term(f => f.CompanyGroupId, companyGroupId);

        // whatever your logic is for adding termination date
        if (includeTerminationDate)
            qc &= q.Term(f => f.TerminationDate, DateTime.UtcNow);

        return qc;
    };
}

Then to use

client.Search<EmployeeDocument>(s => s
    .Query(EmployeeSearchQuery("query", 2, false))
);

emits

{
  "query": {
    "bool": {
      "must": [
        {
          "multi_match": {
            "type": "most_fields",
            "query": "query",
            "minimum_should_match": "90%",
            "fields": [
              "fullName^3",
              "number^3",
              "email",
              "jobNumber",
              "description"
            ]
          }
        },
        {
          "term": {
            "companyGroupId": {
              "value": 2
            }
          }
        }
      ]
    }
  }
}

and

client.Search<EmployeeDocument>(s => s
    .Query(EmployeeSearchQuery("query", 2, true))
);

emits

{
  "query": {
    "bool": {
      "must": [
        {
          "multi_match": {
            "type": "most_fields",
            "query": "query",
            "minimum_should_match": "90%",
            "fields": [
              "fullName^3",
              "number^3",
              "email",
              "jobNumber",
              "description"
            ]
          }
        },
        {
          "term": {
            "companyGroupId": {
              "value": 2
            }
          }
        },
        {
          "term": {
            "terminationDate": {
              "value": "2018-05-16T23:21:16.8309753Z"
            }
          }
        }
      ]
    }
  }
}