comfyui-conditional-string-concat

ComfyUI Conditional String Concat

A custom node for ComfyUI that concatenates multiple text fields, but only includes the ones whose paired checkbox is enabled.

Useful for building prompts (or any text) out of optional fragments — tags, style modifiers, negative terms, etc. — without having to manually delete/re-type text every time you want to toggle a piece on or off.

Features

• Multiple text + enable (boolean) pairs
• Only text from enabled slots is included in the output
• Empty text fields are skipped automatically, even if enabled
• Custom separator (default: , )
• Variable number of slots — use the + Add slot / - Remove slot buttons on the node to grow or shrink how many fields are shown
• Slot count is preserved when you save and reload a workflow

Example

With the following setup:

Slot	Text	Enabled
1	a	false
2	2	true
3	x	false
4	y	true
5	z	true

Output: 2, y, z

Installation

Manual

cd ComfyUI/custom_nodes
git clone https://github.com/bravotan/comfyui-conditional-string-concat.git

Restart ComfyUI afterward.

ComfyUI Manager

Search for "Conditional String Concat" in ComfyUI Manager and install from there.

Usage

1. Add the Conditional String Concat node (found under utils/string)
2. Type text into any of the visible slots
3. Toggle each slot's enable checkbox to control whether it's included
4. Use the + Add slot / - Remove slot buttons to change how many slots are shown (up to 20)
5. Connect the concatenated output wherever you'd use a string — e.g. a prompt input

Note: - Remove slot only hides the field — it doesn't clear its content. Re-adding the slot will restore whatever text was there. Clear the text manually if you want it gone for good.

How it works

• The Python side (__init__.py) declares a fixed pool of optional inputs (text1/enable1 ... text20/enable20) and simply joins whichever ones are enabled and non-empty.
• The JavaScript side (web/) is a small ComfyUI/LiteGraph.js extension that shows or hides slot widgets based on how many slots you've chosen to display, and persists that count via onSerialize / onConfigure so it survives saving and reloading a workflow.

Requirements

No external Python dependencies beyond ComfyUI itself.

License

MIT