Nested aggregation using a loop

[vipulbhavsar94]

Suppose if I have a list of aggregations which I want to nest in an array, how should I go about being able to do that since it expects a parameter for the nested aggregations which means that I'll have to put all the aggregations in the single expression itself and I can't do it by iterating over the loop and inserting the nested aggregations somehow, any other way to achieve this?

[danpaz]

Not sure I followed. Can you show me the final desired elasticsearch query you're aiming for?

[vipulbhavsar94]

The final query I want to achieve is this :
{ "aggregations": { "location_wise": { "terms": { "field": "xAxis" }, "aggs": { "agg_terms_name": { "terms": { "field": "name" }, "aggs": { "agg_terms_class": { "terms": { "field": "class" } } } } } }, "stats": { "stats": { "field": "number of schools" } } } }
I know I can achieve this as :
var body = new BodyBuilder() .aggregation('terms', "xAxis", 'location_wise',null, agg=>agg.aggregation('terms','name',null,null, agg=>agg.aggregation('terms','class'))) .aggregation('stats', 'number of schools', 'stats') .build();

But if I have the list of aggregations to be nested in an array like this:
[{ "aggregationType:"terms", "aggregationField:"name" }, { "aggregationType:"terms", "aggregationField:"class" }]

If these were multiple aggregations, I could have simply used multi line expressions and traversed through the array, but I can't do so in case of nested aggregations, any other way to achieve this?

[danpaz]

I see, so you'd like to programatically generate arbitrarily nested aggregations from an array of aggregation definitions. Though this is more of a javascript question and not really related to the bodybuilder library, I played around with it a I think something like this will work:

var statements = [{ 
  "aggregationType":"terms", 
  "aggregationField":"name" 
}, { 
  "aggregationType":"terms", 
  "aggregationField":"class" 
}, { 
  "aggregationType":"terms", 
  "aggregationField":"grades" 
}]

new Bodybuilder()
  .aggregation('terms', "xAxis", 'location_wise', null, (agg) => {
    var index = 0;
    var nestedAgg;
    function makeNestedAgg(aggBuilder) {
      if (!statements[index]) return nestedAgg;
      var type = statements[index].aggregationType;
      var field = statements[index].aggregationField;
      index++;
      return aggBuilder.aggregation(type, field, (agg) => makeNestedAgg(nestedAgg = agg));
    }
    return makeNestedAgg(agg);
  }) 
  .aggregation('stats', 'number of schools', 'stats') 
  .build();

[vipulbhavsar94]

Thanks, that works.