Elasticsearch Mustache optional parameters

A workaround probably not the most elegant would be to change template query to be a should clause and add a match_all clause for empty list.

example:

{    "filter" : {         "bool" : {            "should" : [                  { "terms" : { "status" : [ "{{#ProductIDs}}","{{.}}","{{/ProductIDs}}"] }}                 {{^ProductIDs}},                {"match_all":{}}                {{/ProductIDs}}            ]        }    }}

Didn't try it, but shouldn't something like this work?

{  "filter" : {    "bool" : {      "must" : [        {{#ProductIDs}}          {{^ProductIDs.isEmpty}}            { "terms" : { "Product.ProductID" : [{{#ProductIDs}}{{.}},{{/ProductIDs}}] } }          {{/ProductIDs.isEmpty}}          {{#ProductIDs.isEmpty}}            {"match_all":{}}          {{/ProductIDs.isEmpty}}        {{/ProductIDs}}        {{^ProductIDs}}          {"match_all":{}}        {{/ProductIDs}}      ]    }  }}

Ain't pretty, maybe there's better way.

My suggestion to overcome this using a JSON template is:

{   "query": {      "bool": {        "must": [            {                "script": {                    "script": {                        "inline": "1==1 {{#ProductIDs}} &&  [\"{{#ProductIDs}}\",\"{{.}}\",\"{{/ProductIDs}}\"].contains(doc['Product.ProductID'].value){{/ProductIDs}}",                        "lang": "painless"                    }                }            }        ]    }}