# Filter Plugin: Elasticsearch

**URL:** https://discuss.elastic.co/t/filter-plugin-elasticsearch/44144
**Category:** Logstash
**Created:** [March 11, 2016, 12:21pm UTC](https://discuss.elastic.co/t/filter-plugin-elasticsearch/44144 "2016-03-11T12:21:05Z")
**Posts on this page:** 1
**Showing post:** 6

<div class="post-metadata">

### Author: ![Christian16](https://avatars.discourse-cdn.com/v4/letter/c/a9a28c/32.png) [@Christian16](https://discuss.elastic.co/u/Christian16)
#### Post date: [March 14, 2016, 2:27pm UTC](https://discuss.elastic.co/t/filter-plugin-elasticsearch/44144/6 "2016-03-14T14:27:30Z")

</div>

i found a solution to retrieve data from a previous event using Ruby Fitler.

```
   if[transaction_Id] {
        ruby {  
            init => "@@map = {}"
            code => "
                @@map[event['verif_id']] = event['transaction_Id']
                @@map[event['session_id']] = event['session_id']
            "
        }
   } else if[classname] == "SendingSMS" {
        ruby{
            code => "
                if event['session_id'] == @@map[event['session_id']] 
                then
                    event['transaction_Id'] = @@map[event['verif_id']] 
                end"
        }
   }

```

Sincerely,  
Chris.

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