# Painless: problem accessing nested object using dot notation **URL:** \ **Category:** Elasticsearch\ **Created:** [October 1, 2018, 6:55pm UTC](https://discuss.elastic.co/t/painless-problem-accessing-nested-object-using-dot-notation/150599 "2018-10-01T18:55:55Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![rozling](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rozling/32/16401_2.png) [@rozling](https://discuss.elastic.co/u/rozling)\ **Post date:** [October 1, 2018, 6:55pm UTC](https://discuss.elastic.co/t/painless-problem-accessing-nested-object-using-dot-notation/150599/1 "2018-10-01T18:55:56Z")
Hi, I'm having problems reindexing data using a painless script. The nested field `context.data.result` is mapped as an object in the destination index, but in some cases the source data is either a string or an array of longs The script attempts to: 1. Check if the field exists 2. Check the field's type 3. If it is a string or array - create a temporary string / array variable - assign the value of the offending field to this variable - change the value of the field to be a new object (passed in via params) using a `put` command - assign the value of the temp variable to the first key/value pair of the new object This works fine for strings, but it's not working for arrays. Here's one document it fails on: ```json { "_index": "logstash-crm-2018.04.29", "_type": "doc", "_id": "ssNuEGMBPRb2-UEOO0NF", "_version": 1, "found": true, "_source": { "context": { "data": { "result": [ 3433229, 3433301, 2993663 ], "resultCount": 3 }, "message": "success", "status": 200 }, "message": "DOCUMENT_VALIDATIONS_NEEDED", "type": "log", "level": 200, "log_type": "json", "source": "/var/www/our-crm/log/our-crm-2018-04-29.log", "datetime": { "timezone_type": 3, "date": "2018-04-29 09:04:08", "timezone": "Europe/London" }, "@version": "1", "level_name": "INFO", "tags": [ "beats_input_codec_plain_applied" ], "@timestamp": "2018-04-29T08:04:09.437Z", "input_type": "log", "service": "crm", "offset": 82722, "beat": { "version": "5.6.8", "name": "aws-hostname", "hostname": "aws-hostname" }, "log_source": "file" } } ``` And here's my Painless script: ```auto { "source": { "index": ["{{source}}"] }, "dest": { "index": "{{dest}}" }, "script": { "source": """ if (ctx._source.context != null) { if (ctx._source.context instanceof String) { String name = ctx._source.context; ctx._source.put(\"context\", params.context); ctx._source.context.name = name } else if (ctx._source.context.data != null) { if (ctx._source.context.data.result instanceof Long) { Long number = ctx._source.context.data.result; ctx._source.put(\"context.data.result\", params.result); ctx._source.context.data.result.number = number } else if (ctx._source.context.data.result instanceof List) { long[] longArray = new long[ctx._source.context.data.result.length]; longArray = ctx._source.context.data.result; ctx._source.put(\"context.data.result\", params.result2); ctx._source.context.data.result.longArray = longArray } } } """, "lang": "painless", "params": { "context": { "name": "blank" }, "result": { "number": 1234 }, "result2": { "longArray": [1234, 5678] } } } } ``` Currently Painless throws an error at this point in the code: ```auto "if (ctx._source.context.data != null) {", " ^---- HERE" ``` And the error message is: ```auto "type": "illegal_argument_exception", "reason": "Illegal list shortcut value [data]." ``` I'm not sure why this would be the case, since I know the source data contains `context.data.result`? ---
**Author:** ![rjernst](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rjernst/32/6363_2.png) [@rjernst](https://discuss.elastic.co/u/rjernst)\ **Post date:** [October 3, 2018, 11:35pm UTC](https://discuss.elastic.co/t/painless-problem-accessing-nested-object-using-dot-notation/150599/2 "2018-10-03T23:35:06Z")
It looks like `ctx._source.context` is an array in your source. So you need to iterate through each value of the array and dereference it by index. So instead of `ctx._source.context.data`, you need a loop like: ```auto for (int i = 0; i < ctx._source.context.length; ++i) { ctx._source.context[i].data } ``` ---
**Author:** ![rozling](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rozling/32/16401_2.png) [@rozling](https://discuss.elastic.co/u/rozling)\ **Post date:** [October 5, 2018, 1:38pm UTC](https://discuss.elastic.co/t/painless-problem-accessing-nested-object-using-dot-notation/150599/3 "2018-10-05T13:38:43Z")
Hi Ryan, thanks for your reply! `result` is definitely an array but `context` is an object, unless I'm misunderstanding something? ---
**Author:** ![rjernst](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rjernst/32/6363_2.png) [@rjernst](https://discuss.elastic.co/u/rjernst)\ **Post date:** [October 14, 2018, 10:53pm UTC](https://discuss.elastic.co/t/painless-problem-accessing-nested-object-using-dot-notation/150599/4 "2018-10-14T22:53:36Z")
Are you sure _all_ of your documents have `context` as an object? The error from painless indicates it found a List. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [November 11, 2018, 10:53pm UTC](https://discuss.elastic.co/t/painless-problem-accessing-nested-object-using-dot-notation/150599/5 "2018-11-11T22:53:38Z")
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