# Plugin Helper: Parser

The `parser` plugin helper manages the lifecycle of the parser plugin.

Here is an example:

```ruby
require 'fluent/plugin/input'

module Fluent::Plugin
  class ExampleInput < Input
    Fluent::Plugin.register_input('example', self)

    # 1. Load parser helper
    helpers :parser

    # Omit `shutdown` and other plugin APIs

    def configure(conf)
      super

      # 2. Create parser plugin instance
      @parser = parser_create
    end

    def start
      super

      # Use parser helper in combination usually with other plugin helpers
      timer_execute(:example_timer, 10) do
        read_raw_data do |text|
          # 3. Call `@parser.parse(text)` to parse raw data
          @parser.parse(text) do |time, record|
            router.emit(tag, time, record)
          end
        end
      end
    end
  end
end
```

For more details, see the following articles:

* [Parser Plugin Overview](/parser.md)
* [Writing Parser Plugins](/plugin-development/api-plugin-parser.md)
* [Parser Plugin](/configuration/parse-section.md)

## Methods

### `parser_create(usage: "", type: nil, conf: nil, default_type: nil)`

This method creates a parser plugin instance with the given parameters.

* `usage`: unique name required for multiple parsers
* `type`: parser type
* `conf`: parser plugin configuration
* `default_type`: default parser type

**Examples**

```ruby
# Create parser plugin instance using <parse> section in fluent.conf during configure phase
@parser = parser_create
@parser.parse(text) do |time, record|
  # ...
end

# Create JSON parser
@json_parser = parser_create(usage: 'parser_in_example_json', type: 'json')
@json_parser.parse(json) do |time, record|
  # ...
end

# Create MessagePack parser
@msgpack_parser = parser_create(usage: 'parser_in_example_msgpack', type: 'msgpack')
@msgpack_parser.parse(msgpack_binary) do |time, record|
  # ...
end
```

## Plugins using `parser`

* [`filter_parser`](/filter/parser.md)
* [`in_exec`](/input/exec.md)
* [`in_http`](/input/http.md)
* [`in_syslog`](/input/syslog.md)
* [`in_tail`](/input/tail.md)
* [`in_tcp`](/input/tcp.md)
* [`in_udp`](/input/udp.md)
* [`out_exec_filter`](/output/exec_filter.md)

If this article is incorrect or outdated, or omits critical information, please [let us know](https://github.com/fluent/fluentd-docs-gitbook/issues?state=open). [Fluentd](http://www.fluentd.org/) is an open-source project under [Cloud Native Computing Foundation (CNCF)](https://cncf.io/). All components are available under the Apache 2 License.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.fluentd.org/plugin-helper-overview/api-plugin-helper-parser.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.