Collection Operations

The Collection Operations node allows workflows to create, manage, and manipulate in-memory collections (such as lists of objects, strings, or numbers) dynamically during execution. It provides a simple way to initialize collections, add or remove elements, and query or serialize them for downstream tasks.

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🧩 Overview

This node is designed for scenarios where you need to:

• Accumulate results across multiple iterations.
• Perform list-based operations (add, remove, get, join, etc.).
• Pass structured data between workflow nodes.
• Convert collections to and from JSON.

It supports most basic collection manipulations found in common programming environments.

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🧠 Supported Operations

Operation	Description
Initialize	Creates a new collection variable of a specified type (e.g., List<string>).
Add	Adds a single value to an existing collection.
AddRange	Adds multiple values (from another collection or array).
Remove	Removes a specific value from the collection (first match).
RemoveAt	Removes an item at a specific index.
Clear	Removes all elements from the collection.
Count	Returns the number of items in the collection.
Contains	Checks if a given value exists in the collection.
Get	Returns the item at a specified index.
GetAll	Returns all elements of the collection.
Join	Joins the collection into a single string, separated by a specified delimiter.
ToJson	Serializes the collection into a JSON string.

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🧾 Inputs

Label	Type	Description	Required	Visible When
Operation	Picklist	The operation to perform.	✅	Always visible
Collection Name	Text	The variable name for the collection (used to reference it later).	✅	Always visible
Collection Type	Picklist	Type of collection to create. Options: List<object>, List<string>, List<int>, List<double>.	❌	Initialize
Value	Text / Object	The value to add, remove, or check for.	❌	Add, Remove, Contains
Values	Text / Array	Multiple values to add at once (e.g., ["A","B","C"]).	❌	AddRange
Index	Number	The index position for retrieving or removing an element.	❌	RemoveAt, Get
Separator	Text	The character(s) used to join list elements. Default: , .	❌	Join
Output Variable Name	Text	Optional variable name to store the result of the operation (e.g., count, joined string, JSON, etc.).	❌	Visible for all operations

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📤 Outputs

Depending on the operation:

Operation	Output Type	Description
Initialize, Add, AddRange, Remove, RemoveAt, Clear, GetAll	Collection	Returns the updated list.
Count	Integer	The total number of elements.
Contains	Boolean	true if the value exists, otherwise false.
Get	Object	The value at the specified index.
Join	String	The concatenated string result.
ToJson	String	JSON string representation of the collection.

If Output Variable Name is provided, the result will be stored in that variable for use in subsequent nodes.

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💡 Example Scenarios

Example 1: Initialize and Add Items

1. Initialize →

   • Operation: Initialize
   • Collection Name: MyList
   • Collection Type: List<string>

2. Add →

   • Operation: Add
   • Collection Name: MyList
   • Value: "First Item"

3. AddRange →

   • Operation: AddRange
   • Values: ["Second","Third","Fourth"]

4. Count →

   • Operation: Count
   • Output Variable Name: ItemCount

Result: MyList = ["First Item", "Second", "Third", "Fourth"]ItemCount = 4

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Example 2: Join and Convert to JSON

1. Join →

   • Operation: Join
   • Collection Name: MyList
   • Separator: ,
   • Output Variable Name: JoinedText

2. ToJson →

   • Operation: ToJson
   • Collection Name: MyList
   • Output Variable Name: MyListJson

Result:

• JoinedText = "First Item, Second, Third, Fourth"
• MyListJson = ["First Item","Second","Third","Fourth"]

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⚠️ Validation & Error Handling

• Required Fields:Operation and Collection Name must be provided.
• Type Mismatch: If an operation targets a non-list variable, execution fails with an error message.
• Index Out of Range: When using Get or RemoveAt, the index must exist in the list.
• Invalid Operation: Any unrecognized operation will return a failure status with message "Unsupported operation: <operation>".

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🧩 Tips

• Use Output Variable Name consistently to store intermediate results between nodes.
• When performing numeric operations, ensure the correct collection type (List<int> or List<double>).
• CollectionOperations is often paired with Loop, Condition, or DataOperations nodes for more complex automation logic.

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🔍 Summary

Feature	Description
Purpose	Manage and manipulate lists and collections dynamically during workflow execution.
Common Uses	Accumulating data, filtering lists, joining strings, serializing arrays.
Key Inputs	Operation, Collection Name, Value/Values, Output Variable Name.
Outputs	Modified collections or computed results (count, boolean, string, JSON).

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✅ Example Use Case: Combine with a Loop Node to aggregate results from repeated API calls, build a list of items, and convert the list to JSON before sending to another service.