Form data and uploaded file will be hashed separately and will be uploaded onto IPFS
Upload data, you data will be then hashed with IPFS. Same data will generate same IPFS hash.
Push to Blockchain
Make a small payment to embed your IPFS hash onto bitcoin blockchain.
Try uploading the same data again, you'll receive a same IPFS hash for your document.
If you want to know more about IPFS (InterPlanetary File System).
Please head over to: https://ipfs.io