A contract upload form is not a decorated file picker. It is a chain of trust from the user’s device to a reviewed, versioned document.
The interface should make the requested document, accepted formats, progress, review state, and next action unmistakable. Most expensive mistakes happen between those states, not on the button itself.
Table of contents
- Design every state before the happy path
- Validate early and explain plainly
- Make review and replacement safe
- Build accessibility into the control
- How this fits the rest of the stack
- FAQ
Design every state before the happy path
- Empty: explain the contract requested and accepted formats.
- Selected: show filename, type, size, and replace action.
- Uploading: show determinate progress and prevent duplicate submission.
- Processing: explain scanning or conversion separately from transfer.
- Success: show version, timestamp, and next step.
- Error: preserve user input and offer a specific recovery action.
Validate early and explain plainly
Display the size and format constraints beside the control, then validate immediately after selection. Say PDF required or file exceeds 10 MB, not invalid input. Client-side checks improve speed, but the server must repeat them because browser values cannot be trusted.
Inspect file signatures, generate safe names, scan content, and store uploads outside executable paths. Do not reveal internal storage locations in an error.
Make review and replacement safe
Before final submission, let the user open the selected contract, confirm the counterparty, and replace the file. After submission, a replacement should create a new version instead of silently overwriting the audit trail.
If signatures follow, show whether the document is draft, awaiting signature, completed, or rejected. Status language should describe the contract, not an invisible backend job.
Build accessibility into the control
Use a visible label, keyboard-operable button, clear focus state, and a live status message for progress. Drag and drop can be a convenience, but it cannot be the only path.
Keep errors associated with the input and move focus thoughtfully after submission. Colour may reinforce a state, but text and icons must carry the meaning too.
How this fits the rest of the stack
Model upload, scanning, versioning, and review as separate states before choosing infrastructure. Price the web service and managed database with the RunxBuild calculator, then ship the workflow from the RunxBuild dashboard.
Useful related references:
- AJAX Form File Upload: FormData, fetch, and a Real Server Handler
- SaaS Full Form: Software as a Service, and the Two Layers Beneath It
- phpMyAdmin Upload Limit: The Four Numbers That Cap Your Import
- Services on RunxBuild
FAQ
Should a contract upload support drag and drop?
It can, but always provide a standard keyboard-accessible file picker as an equal option.
When should the form validate a file?
Show immediate browser feedback after selection, then repeat every security-sensitive check on the server.
Can users replace a submitted contract?
Yes, if the process allows it, but preserve the old version and record who replaced it and when.
What progress should the interface show?
Distinguish transfer progress from server-side scanning or processing so users know whether it is safe to leave.