ReplaceTransformer

Replaces an existing metadata value with another one.

importerJavadoc: ReplaceTransformer

Notes

It is possible to only keep values that changed from a replacement and discard others by setting discardUnchanged to true.

The toField argument is optional.

Not specifying a toValue will delete the matches from sources values.

Storing values in an existing field

If a target field with the same name already exists for a document, values will be added to the end of the existing value list. It is possible to change this default behavior by supplying a PropertySetter.

Can be used both as a pre-parse or post-parse handler.

You can specify whether matches should be made against the whole field value or not (default). You can also specify whether replacement should be attempted on first match only (default) or all occurrences. This last option is only applicable when whole value matching is false.

Examples

The following example replaces occurrences of "apple" to "orange" in the "fruit" field.

YAML

handler:
  class: ReplaceTransformer
  operations:
    - fieldMatcher:
        pattern: fruit
      valueMatcher:
        replaceAll: true
        pattern: apple
      toValue: orange

JSON

{
  "handler": {
    "class": "ReplaceTransformer",
    "operations": [
      {
        "fieldMatcher": {
          "pattern": "fruit"
        },
        "valueMatcher": {
          "replaceAll": true,
          "pattern": "apple"
        },
        "toValue": "orange"
      }
    ]
  }
}

XML

<handler>
  <class>ReplaceTransformer</class>
  <operations>
    <op>
      <fieldMatcher>
        <pattern>fruit</pattern>
      </fieldMatcher>
      <valueMatcher>
        <replaceAll>true</replaceAll>
        <pattern>apple</pattern>
      </valueMatcher>
      <toValue>orange</toValue>
    </op>
  </operations>
</handler>

Usage

Full configuration skeleton, with every option and its default

YAML

class: ReplaceTransformer
label: string
maxReadSize: 0
operations:
  - discardUnchanged: false
    fieldMatcher: {}
    onSet: APPEND
    toField: string
    toValue: string
    valueMatcher: {}
sourceCharset: string

JSON

{
  "class": "ReplaceTransformer",
  "label": "string",
  "maxReadSize": 0,
  "operations": [
    {
      "discardUnchanged": false,
      "fieldMatcher": {},
      "onSet": "APPEND",
      "toField": "string",
      "toValue": "string",
      "valueMatcher": {}
    }
  ],
  "sourceCharset": "string"
}

XML

<handler>
  <class>ReplaceTransformer</class>
  <label>string</label>
  <maxReadSize>0</maxReadSize>
  <operations>
    <op>
      <discardUnchanged>false</discardUnchanged>
      <fieldMatcher/>
      <onSet>APPEND</onSet>
      <toField>string</toField>
      <toValue>string</toValue>
      <valueMatcher/>
    </op>
  </operations>
  <sourceCharset>string</sourceCharset>
</handler>

Properties

Property	Type	Required	Default
label	string	No	-
maxReadSize	integer	No	10000000
operations	ReplaceOperation[]	No	-
sourceCharset	string	No	-

Property Details

label

An optional, user-supplied label for this step in the importer pipeline. It has no effect on processing — it exists purely to help identify this step, for example in large configurations or in the visual configurator.

maxReadSize

Max characters to read at once

operations

One or more replacements to perform, each pairing a fieldMatcher (which fields), a valueMatcher (what to replace) and a toValue (what to put there). They can also write to a different toField and drop values left unchanged. See ReplaceOperation.

sourceCharset

Sets the character encoding of the source document to ensure proper reading and processing.