Use cases

• Query using custom condition
• Return custom field
• Update field with custom value

Query with custom condition

POST /_search
{
    "query": {
        "script" : {
            "script" : {
                "inline": "doc['value'].value > 1"
             }
        }
    }
}

Return custom field

GET /_search
{
  "script_fields": {
    "square_root_field": {
      "script": {
        "inline": "return Math.sqrt(doc['value'].value);"
      }
    }
  }
}

Update field with custom value

POST /_update
{
    "script": "ctx._source.date='2018-03-22T06:01:47+0000'"
}

Get field

• doc['simple_field']
• params['_source']['field_1']['field_2']
• ctx['_source']['field_1']['field_2']

doc['simple_field']

• Can be used in Search and Aggregation script
• Only can be used with simple field
• Fast
• Use more memory

params['_source']['field_1']['field_2']

• Can be used in Search and Aggregation script
• Only can be used any field
• Very slow

ctx['_source']['field_1']['field_2']

• Can be used in Update script
• Only can be used any field

Tips

• We can create complex script using function, if/else, loop
• We can store script to re-use
• Use heredoc <<< in to write script in php

Complex JAVA Script

GET /_search
{
  "script_fields": {
    "square_root_field": {
      "script": {
        "inline": "
            int totalScore(def scores) {
               def total = 0;  
               for (def score : scores) {  
                   total += score;
               }
               return total; 
            }
            if (totalScore(doc['scores']) > 90) {
               return 'passed';
            } else {
               return 'failed';
            };
            "
      }
    }
  }
}

Store Script

POST _scripts/calculate-score
{
  "script": {
    "lang": "painless",
    "source": "Math.log(_score * 2) + params.my_modifier"
  }
}

GET _scripts/calculate-score

DELETE _scripts/calculate-score

heredoc

public $script = <<<JAVA
if (doc['age'] > 18) {
    return 'old';
} else {
    return 'young';
}
JAVA;