Preview Image (DOM) [Stop]

What it is

Preview Image (DOM) [Stop] is the DOM preview from the sibling node, plus one extremely useful button: a stop_review toggle that, when flipped on, halts the entire workflow the moment this node runs so you can look at the image before anything else executes. It's the "review point" pattern - pause the pipeline at a checkpoint, inspect, decide, continue.

The name tells you exactly what it is. "DOM" because the preview renders in a browser-DOM widget with a resizable grid instead of a fixed canvas image. "[Stop]" because of the interrupt. Same rendering engine, one added superpower.

How it works

Backend and frontend are the same as the plain DOM preview: images are flattened, written to temp as PNGs with the workflow metadata embedded, and shown in the DOM grid widget. The difference is in the execute path - when stop_review is active, the node calls ComfyUI's interrupt mechanism and stops processing mid-run, right after the preview has been displayed.

The subtlety worth understanding is when the stop happens. The preview is written and shown first, then execution is interrupted. So you get to see the result before the graph dies on you. The intended flow is an interactive one: run a workflow up to the preview with the toggle on, stop, judge the image, and if it's good, continue or disable the toggle for unattended runs. The toggle is wired as a socketless boolean widget (labelled "active"/"bypass"), so it's a click on the node, not a wire you have to route.

The inputs that matter

• images (required) - the batch to preview.
• stop_review (required, but it's a widget) - default off. Flip it on and the run stops after previewing.

Output:

• IMAGE - the images passed through as a list. It's an output node, so it always runs; the pass-through keeps the graph chainable past the review point.

When you'd use it

When you're testing a long pipeline and don't want the whole thing to plow through expensive downstream steps (an upscale pass, a video encode) before you've confirmed the intermediate image is worth continuing with. Drop it after the point you care about, flip the toggle, and you get a cheap "eyeball it here" checkpoint. It's also handy in shared workflows where you want the next person to approve a stage before the heavy lifting runs.

Installing it

Part of ComfyUI_Eclipse - Manager (search "Eclipse") or:

cd ComfyUI/custom_nodes
git clone https://github.com/r-vage/ComfyUI_Eclipse
pip install -r ComfyUI_Eclipse/requirements.txt

then restart. If you're reviving old workflows, remember this pack is the successor to RvTools_v2 and legacy nodes were removed in v4.0.0 - use the bundled migration tool on old graphs.

Common issues

The main gotcha is forgetting the toggle is on. If your workflow mysteriously stops in the middle every time you queue it, check every [Stop]-style node - this one will cheerfully halt your run until you flip stop_review back to bypass. Also remember the temp-folder rule: previews go to temp, so the image you're approving won't outlive the session unless you route the pass-through into a real save.