It's not clear to me that it's not possible to access the ctx['_source'] inside a function in a painless script. I looked in the documentation and couldn't find anything about it.
Below is an example of the code I was trying to run. The script was giving compilation error.
void initialize(def attrName, def defaultValue) {
if (ctx._source[attrName] == null) {
ctx._source[attrName] = defaultValue;
}
}
initialize("events", []);
initialize("my_counter", 0);
...
...
I did a little refactoring to solve my problem. But I didn't find anything in the documentation about this limitation.
void initialize(def source, def attrName, def defaultValue) {
if (source[attrName] == null) {
source[attrName] = defaultValue;
}
}
initialize(ctx._source, "events", []);
initialize(ctx._source, "my_counter", 0);
...
...
Here is a full example:
PUT my-index-000001/_doc/1
{
"counter" : 1
}
- with error
POST my-index-000001/_update/1
{
"script": {
"source": "void add(def value) { ctx._source.counter += value } add(params.count)",
"lang": "painless",
"params": {
"count": 1
}
}
}
- fixed
POST my-index-000001/_update/1
{
"script": {
"source": "void add(def source, def value) { source.counter += value } add(ctx._source, params.count);",
"lang": "painless",
"params": {
"count": 1
}
}
}