Overview
A form field turns into a file upload control — instead of a text box — based on its field name in Hubstream:
| Field name starts with | Renders as |
|---|---|
HFImages | Image picker — add one or more images, shown as thumbnails |
HFPDFs | PDF picker — add one or more PDF files |
The match ignores case and the automatic HubUI prefix, so fields created in the management UI (which get names like HubUIHFPDFs1TuaU) work as-is, and so do plain HFImages or hfimages2. Anything else — including HF_Images with an underscore — renders as a regular field.
Creating an upload field
- Add a field to your form as usual (see Form Management).
- Name it starting with
HFImages(for photos) orHFPDFs(for documents). - Give it the JSON data type. The submitted value is a JSON payload of file references, so a plain text field (256-character limit) rejects it and the whole submission fails.
What’s accepted
- Images: JPEG, PNG, GIF, WebP.
- PDFs: PDF files only.
- Up to 15 MB per file, multiple files per field.
Files are only accepted after the submission passes the security checks — see How Submissions Are Protected.
How uploads travel: files don’t go straight into Hubstream. They upload to the Hubstream file service, and the submission carries references to them — Hubstream then retrieves the files from the service. So attachments can appear on the record slightly after the submission itself.