elasticsearch:use script to update nested field? - elasticsearch

Question

I want to add a object into the nested field every update time.
For example,I have a doc:
{
"test":[{"remark":"remark1"}]
}
Next time,i want to add a remark object into test field and save the old remark objects.And the result is :
{
"test":[{"remark":"remark1"},{"remark":"remark2"}]
}
How to achieve it？
Edit
I use the script:
{
"script": "ctx._source.test= ((ctx._source.test?: []) += remarkItem)",
"params": {
"remarkItem": {
"remark": "addd"
}
}
}
But,i get the exception:
{
"error": {
"root_cause": [
{
"type": "remote_transport_exception",
"reason": "[es77][10.14.84.77:9300][indices:data/write/update[s]]"
}
],
"type": "illegal_argument_exception",
"reason": "failed to execute script",
"caused_by": {
"type": "script_exception",
"reason": "Failed to compile inline script [ctx._source.test= ((ctx._source.test?: []) += remarkItem)] using lang [groovy]",
"caused_by": {
"type": "script_exception",
"reason": "failed to compile groovy script",
"caused_by": {
"type": "multiple_compilation_errors_exception",
"reason": "startup failed:\na8220b2cf14b8b7ebeead7f068416882d04fa25d: 1: \nclass org.codehaus.groovy.ast.expr.ElvisOperatorExpression, with its value '(ctx._source.test) ? ctx._source.test: []', is a bad expression as the left hand side of an assignment operator at line: 1 column: 82. File: a8220b2cf14b8b7ebeead7f068416882d04fa25d # line 1, column 82.\n CILastCallResultRemark ?: []) += remarkI\n ^\n\n1 error\n"
}
}
}
},
"status": 400
}
edit
Now,i want to add a field to ensure update or insert the object.
For example:
{
"test":[{"remark":"remark1","id":"1"}]
}
When i update the field,when the id exist,i will update the object.On the contrary,i will insert the object.

Answer 1

I suggest to try a script like this, which takes two parameters in argument. It will check if any of the nested objects already contains the given id:
if yes, it will update the given remark
if not, it will insert a new nested object in the test array.
The script goes like this:
def updated = false
ctx._source.test?.each { obj ->
if (obj.id == item.id) {
obj.remark = item.remark
updated = true
}
}
if (!updated) {
ctx._source.test = ((ctx._source.test ?: []) + item)
}
After being inlined and with proper semicolons, the script looks like this:
{
"script": "def updated = false; ctx._source.test?.each { obj -> if (obj.id == item.id) { obj.remark = item.remark; updated = true } }; if (!updated) { ctx._source.test = ((ctx._source.test ?: []) + item)}",
"params": {
"item": {
"remark": "addd",
"id": "1"
}
}
}