# Update a field value using a script processor
**URL:** https://discuss.elastic.co/t/update-a-field-value-using-a-script-processor/179766
**Category:** Elasticsearch
**Created:** [May 6, 2019, 12:21pm UTC](https://discuss.elastic.co/t/update-a-field-value-using-a-script-processor/179766 "2019-05-06T12:21:47Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@sreed](https://discuss.elastic.co/u/sreed)
#### Post date: [May 6, 2019, 12:21pm UTC](https://discuss.elastic.co/t/update-a-field-value-using-a-script-processor/179766/1 "2019-05-06T12:21:47Z")
**My use-case** : Before the document is indexed, I would like to update one of the fields using a script processor (defined in a pipeline). When I try to create a index using the pipeline with the script processor a null-pointer exception is thrown. Any pointers would be of great help.
Created a index
```auto
curl -v -H "Content-Type:application/json" -X PUT http://localhost:9200/students
```
Created a pipeline with script processor
```auto
curl -X PUT "localhost:9200/_ingest/pipeline/my-scriptpipeline" -H 'Content-Type: application/json' -d'
{
"description" : "script pipeline",
"processors" : [
{
"script": {
"source": "ctx._source.age += params.extra",
"params": {
"extra": 2
}
}}]}| json_pp
```
Simulated the pipeline
```auto
curl -X POST "localhost:9200/_ingest/pipeline/my-scriptpipeline/_simulate?verbose" -H 'Content-Type: application/json' -d'
{
"docs": [
{
"_index": "students",
"_type": "student",
"_id": "1",
"_source": {
"name":"Chota Bheem",
"age":10,
"address":"Dholakpur",
}}]}' | json_pp
```
I get a null-pointer exception
```auto
{
"docs" : [
{
"processor_results" : [
{
"error" : {
"script" : "ctx._source.age += params.extra",
"reason" : "runtime error",
"lang" : "painless",
"script_stack" : [
"ctx._source.age += params.extra",
" ^---- HERE"
],
"caused_by" : {
"reason" : null,
"type" : "null_pointer_exception"
},
"type" : "script_exception",
"root_cause" : [
{
"reason" : "runtime error",
"script" : "ctx._source.age += params.extra",
"script_stack" : [
"ctx._source.age += params.extra",
" ^---- HERE"
],
"type" : "script_exception",
"lang" : "painless"
}]}}]}]}
```
---
### Author:  [@spinscale](https://discuss.elastic.co/u/spinscale)
#### Post date: [May 6, 2019, 2:11pm UTC](https://discuss.elastic.co/t/update-a-field-value-using-a-script-processor/179766/2 "2019-05-06T14:11:00Z")
Hey,
no need to use `ctx._source.age`, just try to `ctx.age`.
--Alex
---
### Author:  [@sreed](https://discuss.elastic.co/u/sreed)
#### Post date: [May 7, 2019, 4:25am UTC](https://discuss.elastic.co/t/update-a-field-value-using-a-script-processor/179766/3 "2019-05-07T04:25:39Z")
Thanks Alex. It works!
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [June 4, 2019, 4:25am UTC](https://discuss.elastic.co/t/update-a-field-value-using-a-script-processor/179766/4 "2019-06-04T04:25:51Z")
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