Barcode templates

Scanning a yarn ball-band shouldn't be just a one-shot prefill. It should teach the app what that product is, so the next time anyone scans it (you, a friend, a new install) the answer is there.

That's what barcode templates are for.

The basic flow

You're at the yarn store. You buy two skeins of a Sandnes yarn you've never logged before. At home:

Stash → barcode icon (next to Add yarn).
Camera opens, scan the ball-band.
Purl recognises Sandnes Sunday, opens the Add-yarn form prefilled with the brand, name, weight, fibre, gauge, recommended needle. You just type the colour name and the dye lot.
Save.

That recognition happens because Sandnes Sunday is in the bundled catalogue that ships with Purl.

If the yarn isn't recognised:

(unknown code): the form opens blank with the barcode attached. You fill in brand / name / weight / etc.
Save.

That save quietly creates a barcode template. The next time you (or a friend with the same template) scan the same code, it'll be recognised.

The catalogue

Purl ships with a curated catalogue of ~20 Nordic yarn producers and their lines: DROPS, Sandnes Garn, Ístex, Knitting for Olive, Du Store Alpakka, Hillesvåg, Filcolana, Rauma, Dale, Camilla Pihl, Viking of Norway, Järbo, Svarta Fåret, CaMaRose, Hjertegarn, Isager, Novita, and more.

For most of them: brand, yarn names, weight, fibre, meterage, populated. For some of them: colourways too (full DROPS range, Ístex Lopi numbers, the entire Knitting for Olive named ranges).

The catalogue is read-only at the source but you can edit any entry: your edit forks into your own template store. App updates ship new catalogue entries without overwriting what you've changed.

Barcode templates view

More → Barcode templates opens the management surface.

At the top: a live camera for scanning. Below it: the list of templates you own + everything in the catalogue (which surfaces only when you search, so the day-one list isn't ~150 items long).

Each row: brand · name + a subtitle showing barcode count, weight, fibre. Tap a row to open it.

Inside a template:

Barcodes: a chip list. Add one via the text input; remove via the × on each chip. Multiple barcodes per template is the whole point: manufacturers cycle EAN codes between packaging runs, and an old skein + a fresh one can have different codes for the same product.
Brand / name / weight / fibre / gauge / needle / meters / grams fields.

The search field above the list searches everything (brand, name, weight, fibre, barcodes). Diacritic-folded: "jarbo" finds Järbo.

Duplicates

If you end up with two templates for the same yarn (a blank weight one time, "DK" another time, or a slight name typo), Purl notices: a Possible duplicates card appears at the top of the list. Tap Merge on a group and they fold together: barcodes unioned, blank fields filled from the others, the most-complete entry kept as the primary.

You can also avoid creating duplicates in the first place: v0.1.96+ uses brand + name as the identity for save-time matching, falling back from brand + name + weight, so a blank weight won't fork.

Linking a scanned code to an existing template

If you scan an unknown code but you can see the matching product in your library (or in the catalogue), tap Or attach this barcode to an existing template in the form. A picker opens (searchable across user + catalogue) to find the right product. Tap it, the barcode gets attached, and you don't end up with two templates for the same yarn.

Sharing templates with a friend

More → Barcode templates → share icon in the header. Purl writes a .purlt file with your whole template library and opens the system share sheet. Email it / Drive it / AirDrop it.

Your friend receives the file, taps it (on Android with Purl installed), Purl opens straight to the import screen and merges:

Templates that match by brand + name + weight get their barcodes combined.
New products land as fresh entries.

No yarn / projects / photos cross over. Just the template catalogue.

The flywheel

Over time:

You scan yarn → templates accrue in your library.
You share .purlt with your tester contact (or it rides in your regular .purl backups).
The new templates get folded into the bundled catalogue in a future Purl release.
The next user installing Purl gets your templates as part of the catalogue, ready to recognise on day one.

The whole catalogue is built this way. The folding-in step is manual by design: Purl has no server, so nothing leaves your device unless you choose to share it.