OpenSearch/docs/painless/painless-contexts/painless-ingest-processor-context.asciidoc

[[painless-ingest-processor-context]]
=== Ingest processor context

Use a Painless script in an {ref}/script-processor.html[ingest processor]
to modify documents upon insertion.

*Variables*

`params` (`Map`, read-only)::
        User-defined parameters passed in as part of the query.

{ref}/mapping-index-field.html[`ctx['_index']`] (`String`)::
        The name of the index.

{ref}/mapping-type-field.html[`ctx['_type']`] (`String`)::
        The type of document within an index.

`ctx` (`Map`)::
        Contains extracted JSON in a `Map` and `List` structure for the fields
        that are part of the document.

*Side Effects*

{ref}/mapping-index-field.html[`ctx['_index']`]::
        Modify this to change the destination index for the current document.

{ref}/mapping-type-field.html[`ctx['_type']`]::
        Modify this to change the type for the current document.

`ctx` (`Map`)::
        Modify the values in the `Map/List` structure to add, modify, or delete
        the fields of a document.

*Return*

void::
        No expected return value.

*API*

The standard <<painless-api-reference, Painless API>> is available.

*Example*

To run this example, first follow the steps in
<<painless-context-examples, context examples>>.

The seat data contains:

* A date in the format `YYYY-MM-DD` where the second digit of both month and day
  is optional.
* A time in the format HH:MM* where the second digit of both hours and minutes
  is optional. The star (*) represents either the `String` `AM` or `PM`.

The following ingest script processes the date and time `Strings` and stores the
result in a `datetime` field.

[source,Painless]
----
String[] dateSplit = ctx.date.splitOnToken("-");                     <1>
String year = dateSplit[0].trim();
String month = dateSplit[1].trim();

if (month.length() == 1) {                                           <2>
    month = "0" + month;
}

String day = dateSplit[2].trim();

if (day.length() == 1) {                                             <3>
    day = "0" + day;
}

boolean pm = ctx.time.substring(ctx.time.length() - 2).equals("PM"); <4>
String[] timeSplit = ctx.time.substring(0,
        ctx.time.length() - 2).splitOnToken(":");                    <5>
int hours = Integer.parseInt(timeSplit[0].trim());
int minutes = Integer.parseInt(timeSplit[1].trim());

if (pm) {                                                            <6>
    hours += 12;
}

String dts = year + "-" + month + "-" + day + "T" +
        (hours < 10 ? "0" + hours : "" + hours) + ":" +
        (minutes < 10 ? "0" + minutes : "" + minutes) +
        ":00+08:00";                                                 <7>

ZonedDateTime dt = ZonedDateTime.parse(
         dts, DateTimeFormatter.ISO_OFFSET_DATE_TIME);               <8>
ctx.datetime = dt.getLong(ChronoField.INSTANT_SECONDS)*1000L;        <9>
----
<1> Uses the `splitOnToken` function to separate the date `String` from the
    seat data into year, month, and day `Strings`.
    Note::
    * The use of the `ctx` ingest processor context variable to retrieve the
      data from the `date` field.
<2> Appends the <<string-literals, string literal>> `"0"` value to a single
    digit month since the format of the seat data allows for this case.
<3> Appends the <<string-literals, string literal>> `"0"` value to a single
    digit day since the format of the seat data allows for this case.
<4> Sets the <<primitive-types, `boolean type`>>
     <<painless-variables, variable>> to `true` if the time `String` is a time
     in the afternoon or evening.
     Note::
     * The use of the `ctx` ingest processor context variable to retrieve the
       data from the `time` field.
<5> Uses the `splitOnToken` function to separate the time `String` from the
     seat data into hours and minutes `Strings`.
     Note::
     * The use of the `substring` method to remove the `AM` or `PM` portion of
       the time `String`.
     * The use of the `ctx` ingest processor context variable to retrieve the
       data from the `date` field.
<6> If the time `String` is an afternoon or evening value adds the
     <<integer-literals, integer literal>> `12` to the existing hours to move to
     a 24-hour based time.
<7> Builds a new time `String` that is parsable using existing API methods.
<8> Creates a `ZonedDateTime` <<reference-types, reference type>> value by using
     the API method `parse` to parse the new time `String`.
<9> Sets the datetime field `datetime` to the number of milliseconds retrieved
     from the API method `getLong`.
     Note::
     * The use of the `ctx` ingest processor context variable to set the field
       `datetime`. Manipulate each document's fields with the `ctx` variable as
       each document is indexed.

Submit the following request:

[source,console]
----
PUT /_ingest/pipeline/seats
{
  "description": "update datetime for seats",
  "processors": [
    {
      "script": {
        "source": "String[] dateSplit = ctx.date.splitOnToken('-'); String year = dateSplit[0].trim(); String month = dateSplit[1].trim(); if (month.length() == 1) { month = '0' + month; } String day = dateSplit[2].trim(); if (day.length() == 1) { day = '0' + day; } boolean pm = ctx.time.substring(ctx.time.length() - 2).equals('PM'); String[] timeSplit = ctx.time.substring(0, ctx.time.length() - 2).splitOnToken(':'); int hours = Integer.parseInt(timeSplit[0].trim()); int minutes = Integer.parseInt(timeSplit[1].trim()); if (pm) { hours += 12; } String dts = year + '-' + month + '-' + day + 'T' + (hours < 10 ? '0' + hours : '' + hours) + ':' + (minutes < 10 ? '0' + minutes : '' + minutes) + ':00+08:00'; ZonedDateTime dt = ZonedDateTime.parse(dts, DateTimeFormatter.ISO_OFFSET_DATE_TIME); ctx.datetime = dt.getLong(ChronoField.INSTANT_SECONDS)*1000L;"
      }
    }
  ]
}
----