Data Processing Nodes

Data Processing nodes convert raw upstream content into the format required by downstream nodes. This guide covers all 5 Data Processing nodes.

Except for Variable Management, processing does not modify the original variable. Save a result to a new output variable before using it downstream.

Data Processing nodes

Variable Management

Create or update variables during a workflow using the same editor as Start.

Use it to:

• Prepare default values at a particular stage.
• Update a variable based on an earlier result.
• Define several configuration values for one downstream path.

The later definition of a name overwrites the earlier value. A Variable Management node affects only reachable downstream paths and does not make values available to upstream nodes.

For naming, types, and JSON, see Variables and Data.

Variable Management node

Extract Text

Uses a regular expression to extract content from a selected variable and saves it to an output variable.

Configure:

• Input variable.
• Regular expression or a common-rule shortcut.
• Case sensitivity.
• Whether to return only the first match.
• Output variable name.

For example, with:

Order: ZY-20260724, Status: Completed

this expression extracts the order number:

ZY-\d+

Use test data when the match is uncertain. Returning the first match suits a single value; for every match, confirm that downstream nodes support the result structure.

Regular Expressions

Search the following resources for regular-expression reference material:

• Regular Expression Tutorial - Runoob
• Common Regular Expressions

Parse JSON

Parses JSON text in a selected variable into an object and saves it to a new variable.

The input must be valid JSON:

{"name":"Example Product","price":99.9,"in_stock":true}

Common combination:

Listen for Request Results → Parse JSON → Extract Field

If the input includes an API prefix, extra log text, or incomplete JSON, use Extract Text first and then parse the cleaned content.

Extract Field

Reads a named field from an array, object, or Unknown variable and saves it to an output variable.

Enter according to the structure:

• Object: Enter an object key such as username.
• Array: Enter an array index.
• Unknown: Use the runtime structure and validate with debugging.

Object example:

{"username":"demo@example.com","roles":["admin","editor"]}

Extracting username returns demo@example.com. To read roles, pass the first result to another Extract Field node.

Array indexes follow programming rules and differ from the user-facing natural indexes in element selectors. Follow the node hint and test data.

Randomly Extract a Field

Selects one field at random from an array, object, or Unknown value and saves it to an output variable.

Use it to select a keyword, message template, or test record from a materials list. An empty input has no valid result, so check existence with IF or guarantee data upstream.

The result can differ on every run. Use Extract Field for repeatable validation or For Each Data Item for complete traversal.

Processing Examples

Parse an API Response

Listen for Request Results → Parse JSON → Extract Field → Save to Excel

Listen for Request Results configuration

Parse JSON configuration

Extract Field configuration

Save the transformed result to Excel

1. Listen for the API response and save it as response_text.
2. Parse JSON and save it as response_data.
3. Extract the target field from response_data.
4. Write the final variable to Excel.

Read an Identifier from Text

Get Clipboard Content → Extract Text → Enter Text

1. Read clipboard text.
2. Extract the business identifier with a regular expression.
3. Enter the output variable into a page form.

Select One Material at Random

1. Create an array variable named messages in Start.
2. Add Randomly Extract a Field and select messages as input.
3. Save the result as current_message.
4. Reference ${current_message} in Enter Text.

Troubleshooting

JSON Parsing Fails

Use ASCII quotes, brackets, and commas, and remove text outside the JSON value. Empty or truncated API responses also fail parsing.

Extracted Field Is Empty

Inspect the upstream variable structure and check object-key case and array index. Object keys are case-sensitive.

An Updated Variable Still Returns the Old Value

Confirm that the using node is downstream of Variable Management and that no branch bypasses the update. A new value takes effect only when execution reaches the new definition.

Random Result Is Unstable

This is expected. Use Extract Field for deterministic debugging or For Each Data Item to process everything.

Related Guides

• Variables and Data: Review types, names, and overwrite rules.
• Data Collection and Storage Nodes: Read page, request, and file data.
• Flow Control Nodes: Process data by condition or loop.