# Can I conditionally trigger a processor based on the current nested iteration or execute a plugin in script?
**URL:** https://discuss.elastic.co/t/can-i-conditionally-trigger-a-processor-based-on-the-current-nested-iteration-or-execute-a-plugin-in-script/262288
**Category:** Elasticsearch
**Created:** [January 26, 2021, 10:19pm UTC](https://discuss.elastic.co/t/can-i-conditionally-trigger-a-processor-based-on-the-current-nested-iteration-or-execute-a-plugin-in-script/262288 "2021-01-26T22:19:48Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@dswitzer](https://discuss.elastic.co/u/dswitzer)
#### Post date: [January 26, 2021, 10:19pm UTC](https://discuss.elastic.co/t/can-i-conditionally-trigger-a-processor-based-on-the-current-nested-iteration-or-execute-a-plugin-in-script/262288/1 "2021-01-26T22:19:48Z")
Is there a way to process an attachment conditionally for a nested object that's represented by an array?
I looked into the foreach processor with a conditional `if`, but the `ctx` object does not appear to hold a reference to the current array position, so I cannot find a way to write the `if` in a way that's valid.
I've also been playing around with the `script` processor to see if I could find to loop through the property and conditional process each item, but I can't find a way to access the plugin logic from the painless script.
Here's a simplified version of the index I'm using:
```auto
{
"mappings": {
"properties": {
"title": { "type": "text" },
"keywords": { "type": "keyword" },
"article": {
"type": "nested",
"properties": {
"id": {
"type": "text"
},
"content": {
"type": "text"
},
"type": {
"type": "text"
}
}
}
}
},
"settings": {
"number_of_shards": 1,
"number_of_replicas": 2
}
}
```
An article document might look like this:
```auto
{
"title"="My article"
, "keywords"=[]
, "article": [
{type: "text", "id": "basic", content: "Some text"}
, {type: "attachment", "id": "file-id-1", content: "base64 encoded data..."}
, {type: "attachment", "id": "file-id-2", content: "base64 encoded data..."}
]
}
```
My goal is to process the `article` nested object, but only process the array items that have a `type` equal to `attachment`.
My first attempt, was to add a conditional statement to my pipeline:
```auto
{
"description" : "Extract attachment information from arrays",
"processors" : [
{
"foreach": {
"field": "article",
"processor": {
"attachment": {
"if": "ctx.article.type == \"attachment\""
, "target_field": "_ingest._value.content"
, "field": "_ingest._value.content"
}
}
}
}
]
}
```
However, the `ctx` variable holds the root document object and I cannot figure out a way to access the current index in the article collection.
Next, I tried implementing a script, but I cannot figure out how to programmatically trigger the `attachment` process. The follow code was the basic code I was working off and it does successfully remove the `content` key for attachments, but what I want to do is replace the base64 data with the extract text.
```auto
{
"description" : "Extract attachment information from arrays"
, "processors" : [
{
"foreach": {
"field": "article",
"processor": {
"script": {
"lang": "painless"
, "source": #serializeJSON('
ctx.article.stream()
.filter(x -> x.type == "attachment")
.forEach(x -> x.remove("content"))
;
')#
}
}
}
}
]
}
```
Is there a way to do what I want?
---
### Author:  [@dswitzer](https://discuss.elastic.co/u/dswitzer)
#### Post date: [January 27, 2021, 3:22pm UTC](https://discuss.elastic.co/t/can-i-conditionally-trigger-a-processor-based-on-the-current-nested-iteration-or-execute-a-plugin-in-script/262288/2 "2021-01-27T15:22:48Z")
In case no one has a solution to this problem, what I'm doing currently as an intermittent step is to send attachments to a simulated pipeline to extract the text and then using those results when updating the document. This of course requires multiple steps, but I can send the attachments in bulk.
So here's an example of what I'm sending:
```auto
POST /_ingest/pipeline/_simulate`
```
```auto
{
"pipeline" :
{
"description" : "Extract attachment information from arrays",
"processors" : [
{
"foreach": {
"field": "attachments",
"processor": {
"attachment": {
"target_field": "_ingest._value.attachment",
"field": "_ingest._value.data"
}
}
}
}
, {
"foreach": {
"field": "attachments",
"processor": {
"remove": {
"field": "_ingest._value.data"
}
}
}
}
]
},
"docs": [{
"_index": "tmp_attachment_pipeline_simulation",
"_id": "a92cb4de963529804557f465570fab9d",
"_source": {
"attachments": [
{ "filepath":"/some/path/to/file1", "data":"c29tZSBleGFtcGxlIHRleHQ=" }
, { "filepath":"/some/path/to/file2", "data":"c29tZSBleGFtcGxlIHRleHQ=" }
]
}
}]
}
```
You would just replace the `attachments` array with the input you want to send and then process the results to extract the `content` an use it in your document model.
I'm still looking for a way to do this in a single step, but for time being this works.
Anyone have a better solution?
---
### Author:  [@dswitzer](https://discuss.elastic.co/u/dswitzer)
#### Post date: [January 27, 2021, 7:01pm UTC](https://discuss.elastic.co/t/can-i-conditionally-trigger-a-processor-based-on-the-current-nested-iteration-or-execute-a-plugin-in-script/262288/3 "2021-01-27T19:01:07Z")
Here's something a pipeline that does what I want, but I don't like having to fall back to failing when the `content` key isn't base64. I'd rather just conditionally process it instead (plus it's theoretically possible the `content` could happen to be a valid base64 string, which would confuse things.)
Is there anyway to get the `if` property on the `foreach` or `attachment` process to see the current iteration value, so that I could just skip if the current article type was not `attachment` the processor is skipped?
```auto
{
"pipeline" :
{
"description" : "Extract attachment information from arrays",
"processors" : [
{
"foreach": {
"field": "article",
"processor": {
"attachment": {
"field": "_ingest._value.content"
, "target_field": "_ingest._value.attachment"
, "ignore_failure": true
}
}
}
}
, {
"script": {
"lang": "painless"
, "source": "ctx.article.stream().filter(x -> x.type == \"attachment\").forEach(x -> { x.content = x.attachment?.content; x.remove(\"attachment\"); });"
}
}
]
}
, "docs": [{
"_index": "tmp_test",
"_id": "a92cb4de963529804557f465570fab9d",
"_source": {
"title": "My Title"
, "keywords": []
, "article": [
{
"type" : "text",
"title" : "Basic",
"id" : "basic",
"content" : "This is some text."
},
{
"type" : "text",
"title" : "Intermediate",
"id" : "intermediate",
"content" : "Some secondary content"
},
{
"type" : "attachment",
"title" : "the_file_name.pdf",
"id" : "file-id-1",
"content" : "base64 encoded data..."
},
{
"type" : "attachment",
"title" : "the_file_name.docx",
"id" : "file-id-2",
"content" : "base64 encoded data..."
},
]
}
}]
}
```
Is there a better way to do this?
---
### Author:  [@dswitzer](https://discuss.elastic.co/u/dswitzer)
#### Post date: [February 16, 2021, 4:17pm UTC](https://discuss.elastic.co/t/can-i-conditionally-trigger-a-processor-based-on-the-current-nested-iteration-or-execute-a-plugin-in-script/262288/4 "2021-02-16T16:17:48Z")
Is there are better way to do this?
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [March 16, 2021, 4:18pm UTC](https://discuss.elastic.co/t/can-i-conditionally-trigger-a-processor-based-on-the-current-nested-iteration-or-execute-a-plugin-in-script/262288/5 "2021-03-16T16:18:01Z")
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