DeepsetRegexParser

Extract text from a string or chat message using a regular expression pattern.

Deprecation Notice

This component is deprecated. Use RegexTextExtractor from Haystack instead. Existing pipelines that use this component continue to work for now.

Key Features

• Extracts text using a regex pattern with capture groups.
• Accepts plain strings or lists of ChatMessage objects as input.
• Can search all messages or only the last message in a chat history.
• Supports returning a single match or all matches.

Configuration

1. Drag the DeepsetRegexParser component onto the canvas from the Component Library.
2. Click the component to open the configuration panel.
3. Enter the regex_pattern with at least one capture group to extract the desired text.
4. Configure consider_all_messages, return_all_matches, and return_empty_on_no_match as needed.

Connections

DeepsetRegexParser accepts text_or_messages as input — either a string or a list of chat messages. It outputs captured_text for a single match or captured_texts for multiple matches.

Connect a Generator or chat component to the input. Connect the output to components that need the extracted value, such as DeepsetGitHubIssueViewer.

Usage Examples

Basic Configuration

  DeepsetRegexParser:
    type: deepset_cloud_custom_nodes.parsers.regex_parser.DeepsetRegexParser
    init_parameters:
      regex_pattern: '<issue url="(.+)">'
      consider_all_messages: false
      return_empty_on_no_match: false
      return_all_matches: false

Using the Component in a Pipeline

This example extracts a URL from a chat message:

# haystack-pipeline
components:
  regex_parser:
    type: deepset_cloud_custom_nodes.parsers.regex_parser.DeepsetRegexParser
    init_parameters:
      regex_pattern: '<issue url="(.+)">'
      consider_all_messages: false
      return_empty_on_no_match: false
      return_all_matches: false

inputs:
  text_or_messages:
    - regex_parser.text_or_messages

outputs:
  captured_text: regex_parser.captured_text

Parameters

Inputs

Parameter	Type	Default	Description
text_or_messages	str or List[ChatMessage]		Text or chat messages to search.

Outputs

Parameter	Type	Default	Description
captured_text	str		First captured text when return_all_matches is False.
captured_texts	List[str]		All captured texts when return_all_matches is True.

Init Parameters

These are the parameters you can configure in Pipeline Builder:

Parameter	Type	Default	Description
regex_pattern	str		Regular expression pattern with a capture group to extract text.
consider_all_messages	bool	False	If True, applies the regex to all chat messages. If False, only the last message is searched.
return_empty_on_no_match	bool	False	If True, returns an empty dictionary when no match is found.
return_all_matches	bool	False	If True, returns all matches as captured_texts. If False, returns only the first match as captured_text.

Run Method Parameters

These are the parameters you can configure for the component's run() method. This means you can pass these parameters at query time through the API, in Playground, or when running a job. For details, see Modify Pipeline Parameters at Query Time.

Parameter	Type	Default	Description
text_or_messages	str or List[ChatMessage]		Text or chat messages to search.