[[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[] split(String s, char d) {                                   <1>
    int count = 0;

    for (char c : s.toCharArray()) {                                 <2>
        if (c == d) {
            ++count;
        }
    }

    if (count == 0) {
        return new String[] {s};                                     <3>
    }

    String[] r = new String[count + 1];                              <4>
    int i0 = 0, i1 = 0;
    count = 0;

    for (char c : s.toCharArray()) {                                 <5>
        if (c == d) {
            r[count++] = s.substring(i0, i1);
            i0 = i1 + 1;
        }

        ++i1;
    }

    r[count] = s.substring(i0, i1);                                  <6>

    return r;
}

String[] dateSplit = split(ctx.date, (char)"-");                     <7>
String year = dateSplit[0].trim();
String month = dateSplit[1].trim();

if (month.length() == 1) {                                           <8>
    month = "0" + month;
}

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

if (day.length() == 1) {                                             <9>
    day = "0" + day;
}

boolean pm = ctx.time.substring(ctx.time.length() - 2).equals("PM"); <10>
String[] timeSplit = split(
        ctx.time.substring(0, ctx.time.length() - 2), (char)":");    <11>
int hours = Integer.parseInt(timeSplit[0].trim());
int minutes = Integer.parseInt(timeSplit[1].trim());

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

String dts = year + "-" + month + "-" + day + "T" +
        (hours < 10 ? "0" + hours : "" + hours) + ":" +
        (minutes < 10 ? "0" + minutes : "" + minutes) +
        ":00+08:00";                                                 <13>

ZonedDateTime dt = ZonedDateTime.parse(
         dts, DateTimeFormatter.ISO_OFFSET_DATE_TIME);               <14>
ctx.datetime = dt.getLong(ChronoField.INSTANT_SECONDS)*1000L;        <15>
----
<1> Creates a `split` <<painless-functions, function>> to split a
    <<string-type, `String`>> type value using a <<primitive-types, `char`>>
    type value as the delimiter. This is useful for handling the necessity of
    pulling out the individual pieces of the date and time `Strings` from the
    original seat data.
<2> The first pass through each `char` in the `String` collects how many new
    `Strings` the original is split into.
<3> Returns the original `String` if there are no instances of the delimiting
    `char`.
<4> Creates an <<array-type, array type>> value to collect the split `Strings`
    into based on the number of `char` delimiters found in the first pass.
<5> The second pass through each `char` in the `String` collects each split
    substring into an array type value of `Strings`.
<6> Collects the last substring into the array type value of `Strings`.
<7> Uses the `split` function to separate the date `String` from the seat data
    into year, month, and day `Strings`.
    Note::
    * The use of a `String` type value to `char` type value
      <<string-character-casting, cast>> as part of the second argument since
      character literals do not exist.
    * The use of the `ctx` ingest processor context variable to retrieve the
      data from the `date` field.
<8> Appends the <<string-literals, string literal>> `"0"` value to a single
    digit month since the format of the seat data allows for this case.
<9> Appends the <<string-literals, string literal>> `"0"` value to a single
    digit day since the format of the seat data allows for this case.
<10> 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.
<11> Uses the `split` 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 a `String` type value to `char` type value
       <<string-character-casting, cast>> as part of the second argument since
       character literals do not exist.
     * The use of the `ctx` ingest processor context variable to retrieve the
       data from the `date` field.
<12> 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.
<13> Builds a new time `String` that is parsable using existing API methods.
<14> Creates a `ZonedDateTime` <<reference-types, reference type>> value by using
     the API method `parse` to parse the new time `String`.
<15> 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[] split(String s, char d) { int count = 0; for (char c : s.toCharArray()) { if (c == d) { ++count; } } if (count == 0) { return new String[] {s}; } String[] r = new String[count + 1]; int i0 = 0, i1 = 0; count = 0; for (char c : s.toCharArray()) { if (c == d) { r[count++] = s.substring(i0, i1); i0 = i1 + 1; } ++i1; } r[count] = s.substring(i0, i1); return r; } String[] dateSplit = split(ctx.date, (char)\"-\"); 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 = split(ctx.time.substring(0, ctx.time.length() - 2), (char)\":\"); 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;"
        }
      }
    ]
}
----