Elastic search - aggregation filter for product options - ruby-on-rails

Question

I have a products catalogue where every product is indexed as follows (queried from http://localhost:9200/products/_doc/1) as sample:
{
"_index": "products_20201202145032789",
"_type": "_doc",
"_id": "1",
"_version": 1,
"_seq_no": 0,
"_primary_term": 1,
"found": true,
"_source": {
"title": "Roncato Eglo",
"description": "Amazing LED light made of wood and description continues.",
"price": 3990,
"manufacturer": "Eglo",
"category": [
"Lights",
"Indoor lights"
],
"options": [
{
"title": "Mount type",
"value": "E27"
},
{
"title": "Number of bulps",
"value": "4"
},
{
"title": "Batteries included",
"value": "true"
},
{
"title": "Ligt temperature",
"value": "warm"
},
{
"title": "Material",
"value": "wood"
},
{
"title": "Voltage",
"value": "230"
}
]
}
}
Every option contains different value, so there are many Mount type values, Light temperature values, Material values, and so on.
How can I create an aggregation (filter) where I can let customers choose between various Mount Type options:
[ ] E27
[X] E14
[X] GU10
...
Or let them choose from different Material options displayed as checkboxes:
[X] Wood
[ ] Metal
[ ] Glass
...
I can handle it on frontend once the buckets are created. Creation of different buckets for these options is What I am struggling with.
I have succesfully created and displayed and using aggregations for Category, Manufacturer and other basic ones. Thes product options are stored in has_many_through relationships in database. I am using Rails + searchkick gem, but those allow me to create raw queries to elastic search.

Answer 1

The prerequisite for such aggregation is to have options field as nested.
Sample index mapping:
PUT test
{
"mappings": {
"properties": {
"title": {
"type": "keyword"
},
"options": {
"type": "nested",
"properties": {
"title": {
"type": "keyword"
},
"value": {
"type": "keyword"
}
}
}
}
}
}
Sample docs:
PUT test/_doc/1
{
"title": "Roncato Eglo",
"options": [
{
"title": "Mount type",
"value": "E27"
},
{
"title": "Material",
"value": "wood"
}
]
}
PUT test/_doc/2
{
"title": "Eglo",
"options": [
{
"title": "Mount type",
"value": "E27"
},
{
"title": "Material",
"value": "metal"
}
]
}
Assumption: For a given document a title under option appears only once. For e.g. there can exists only one nested document under option having title as Material.
Query for aggregation:
GET test/_search
{
"size": 0,
"aggs": {
"OPTION": {
"nested": {
"path": "options"
},
"aggs": {
"TITLE": {
"terms": {
"field": "options.title",
"size": 10
},
"aggs": {
"VALUES": {
"terms": {
"field": "options.value",
"size": 10
}
}
}
}
}
}
}
}
Response:
{
"took" : 2,
"timed_out" : false,
"_shards" : {
"total" : 1,
"successful" : 1,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : {
"value" : 2,
"relation" : "eq"
},
"max_score" : null,
"hits" : [ ]
},
"aggregations" : {
"OPTION" : {
"doc_count" : 4,
"TITLE" : {
"doc_count_error_upper_bound" : 0,
"sum_other_doc_count" : 0,
"buckets" : [
{
"key" : "Material",
"doc_count" : 2,
"VALUES" : {
"doc_count_error_upper_bound" : 0,
"sum_other_doc_count" : 0,
"buckets" : [
{
"key" : "metal",
"doc_count" : 1
},
{
"key" : "wood",
"doc_count" : 1
}
]
}
},
{
"key" : "Mount type",
"doc_count" : 2,
"VALUES" : {
"doc_count_error_upper_bound" : 0,
"sum_other_doc_count" : 0,
"buckets" : [
{
"key" : "E27",
"doc_count" : 2
}
]
}
}
]
}
}
}
}